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BMW FAQ.15
BMW Digest FAQ Version 4.1

Section 15: E30 ('84-'91 3-series)


Table of Contents:

15.1: Overview

         15.1.1:   325e vs 325i (or "what's an ETA?")
         15.1.2:   325iX (AWD)
         15.1.3:   323
    15.2: Body
         15.2.1:   Water Leaks
         15.2.2:   Tucking in large front bumpers
    15.3: Engine
         15.3.1:   Adjusting valves
         15.3.2:   Transfer Fuel Pump
         15.3.3:   Early twin cam fours' coolant leaks
         15.3.4:   Small six (M20) head bolts
         15.3.5:   'i motor oil leak
         15.3.6:   ETA head job
         15.3.7:   Idle problems
         15.3.8:   Timing Belt

15.4: Suspension & Steering
15.5: Brakes
15.6: HVAC
15.7: Electrical

         15.7.1:   Jerky Wipers
         15.7.2:   Erratic blinkers
         15.7.3:   Wiring fog lights to work with high beams
         15.7.4:   Service Indicator Lights
         15.7.5:   Finding 'iC check-control relays
         15.7.6:   Installing 318 cruise control
         15.7.7:   Fixing Erratic Clock (not OBC)
         15.7.8:   Adjusting Headlights
         15.7.9:   Killing the Key Gong
         15.7.10:  Replacing OBC bulbs
    15.8: Misc
         15.8.1:   Steel wheel center caps
    15.9: Performance
         15.9.1:   ETA Differentials
         15.9.2:   MCU switch settings
         15.9.3:   ETA engine performance
         15.9.4:   Racing Harness Install
         15.9.5:   Sway Bar mount points

15.1: Overview
15.1.1: 325e vs 325i (E30)
(by Rick Kjeldsen, fcmk_at_watson.ibm.com)

>Whats the difference between the 325e and the 325i?

The engine. The 'e uses the economy minded small 6 ETA engine, while the 'i uses a more performance tuned version.

Both engines share the same block and are in many ways very similar. The 'e was designed during the 70s gas crunch, so the emphasis is on mpg. BMWs solution to making a non-boring economy car was to use high torque and low RPMs, so the engine was designed from the bottom up with that in mind. With respect to the 'i it has a longer throw crank (and so is 2.7 liters vs 2.5), has the intake and exhaust tuned for low RPM torque, uses low friction bearings and 4 instead of 7 on the cam shaft, and uses weaker valve springs for less frictional losses. It's chip and cam profile are set for very lean and effecient running. It is generally matched with a very tall rearend ratio to run at low highway RPMs.

So the engine has very high torque (170 ft/lbs) at quite a low speed (~3500 RPM). It has a low redline (4700 stock) though, so HP (= torque*RPM) is only about 125. It pulls smooth and strong from idle to redline because the torque curve is very flat.

The result is a car that feels smooth and powerful in daily driving. It accelerates well (faster from 0-60 than a 2002tii was stock), but it won't win drag races. Because it's peak torque is in the RPM range we use day to day on the street, it often feels more powerful than the 'i cars. In stock form it will easily get >30 mpg on the highway, and cruises comfortably at triple digit speeds. The tall gearing means highway RPM is very low (just over 2000 at 65), so it is smooth and quiet. The engine also seems to be very reliable, probably because of the softer valve springs and lower RPMs than the 'i engines, it seems to have fewer problems.

The down side is that the tall gearing and low RPM limit make the car feel less thrilling when pushed than car enthusiasts like. You hit the rev limiter very quickly in the first couple of gears. You have to down-shift for crisp highway passes. In the US, the 325 was marketed as a performance car and the ETA engine disappointed a lot of people because of that. So in the late 80s BMW redisigned the engine with a shorter throw crank, different intake/exhaust plumbing, different cam timing and stiffer valve springs, different programming and gearing to make the 'i engine (M20/B25). This produces slightly less torque (165 ft/lbs) at a much higher 4500 RPM. It can rev to 6500 RPM, so produces far more HP (165 hp). It has a much peakier torque curve, so it feels somewhat flat at low RPMs, but comes on strong above about 4000. It loves to rev, and sounds wonderful doing it, but can be annoying in traffic and around town because it doesn't pull as strong in the low end. Because the gearing is lower, it spins faster on the highway. It will get 3-5 mpg less than an 'e car and is about a second faster 0-60. The useable top end (where acceleration falls off, so it takes much longer to go a bit faster) is about 10-15 mph better than the 'e.

>Which is the better/more
>expensive of the two?

"Better" depends on what you like. I really like the powerful low end torque of the 'e. It's a wonderful commuter car, good around town, excellent on long trips. With a few minor tweeks it gets a much more exciting top end (chip to increase redline and take care of some of the minor drivability bugs caused by the very lean programming of the stock computer, and a somewhat lower differential ratio to increase torque to the wheels) without sacrificing the smooth powerful low end. My 'e is by far my favorite car for daily driving, many people seem to prefer the 'i. That engine got rave reviews from car-buff mags when it came out. In stock form it feels much more like a performance car than an 'e. Because it has a better reputation and is used in the newer E30s, you will pay slightly more for an 'i.

I'd say to drive them both, and decide which you like. They are both wonderful, reliable engines. If performance is your primary goal you will probably prefer the 'i. For a reliable commuter car the 'e probably has a slight edge. An automatic on an 'e can feel pretty slow.

rick
'87 325es
'90 325iX
'88 M3

(Editors NOTE: In '88 BMW had already introduced the 'i engine. For one more year they sold the 'e engine in the base model 325 and the 528e, but they modified it slightly, maintaining the long stroke crankshaft, but switching to the 'i head and doing some other mods to produce more power than the original 'e. This is often refered to as the "super eta".)


(by tedcrum_at_garnet.berkeley.edu (Ted Crum))

According to the BMP catalog, the m.y. '88 528e ("super eta") not only has the same head as the 87-91 325i, but it also uses the same dual valve springs. It also shows the 1/87 - 9/87 eta using the same valves, guides, and springs as the "i", but with a different head (fewer active cam bearings?)
...
Also, they show the (3/87-on) super e having different injectors and airmeter than the earlier e's, but not the same as the 325i parts.


15.1.2: 325iX (AWD)
(by Gorden Haines <GAHAINES_at_aol.com> or ghaines_at_hops.entertain.com)

The 325iX was produced from '86 through '91 and imported into the U.S. for model years '88-'91. The iX has viscous couplings (filled with silicone) in the drivetrain to split torque front to rear and also in the rear axle to provide limited slip. Handling in the dry is quite satisfactory, particularly with a few mods that I've made (cutting the front springs to lower the front 1-1/2 inches, adding a stiff rear bar, installing Koni sport shocks and a Dinan chip, upgrading bushings and running D40M2's. The iX is very satisfactory on the track and that it will not be embarassed by any E30 with a close-to-stock engine.

But the iX is really in it's glory in inclement weather. With studded Hakkapelitta 10's, the iX is awesome. Even on the most slippery surfaces (including the ice on the lake at Georgetown, CO) the iX can accelerate at full throttle after the first several yards. The ABS which includes a special program (not included in the ordinary 325) for low friction surfaces is also very impressive. Jeeps!, Ford Exploders and Chevy Blazeers have no idea what left them at the stop light. If you love BMWs and need a car for all seasons, this is your car!

The '88s were available only as a 2dr loaded with standard features such as Recaro seats, electric sunroof, map lights, full trip computer and upgraded radio. In '89 a 4dr was offered, but many items were added cost options. The '89 and later models came with a removable rear armrest and skibag and had smaller color-coordinated bumpers. These later models also had a 15" alloy spare rather than a 14" steel spare wheel. A driver airbag was added in some '90 and all '91 models. All models came with special body side moulding and 15" wheels. Asking prices in January '95 in the prime Denver market range from about $10K for '88s to $23K for '91s.

The iX viscous couplings on the 325iX are filled with silicone and are not computer controlled. The one behind the transmission splits torque front to rear (nominally 37/63%). A series of plates with holes and slots turn in the silicone fluid. Some plates are attached to the input front axle driveshaft and some are attached to the rear axle driveshaft. Normally the plates turn at the same rate without relative motion. The silicone becomes very viscous as soon as it is heated by friction and shear caused by differences between the motion of the plates. This tends to lock the driveshafts. If the rear wheels and driveshaft are slipping and turning faster than the front, friction between the plates increases, slippage is reduced, the rear wheel spin is reduced and the power from the input shaft is transferred to the front.

The drive system add only 140lb. to the vehicle and is very reliable. The viscous couplings are sealed permanently and require no maintenace. The only additonal maintenance items required are changes of 1) the front differential oil (GL-5 90 weight, same as the rear) and 2) the transfer case fluid which is ATF. All drivetrain fluids should be changed at "Inspeciton II", nominally at 30K miles.

The front wheels always have some torque transmitted to them. BMW choose this ratio (37/63) because this corresponds to the weight distribution on each axle under full acceleration. This avoids the problem typical of front wheel drive vehicles in which the front wheels spin under acceleration due to weight transfer to the rear. Road & Track (April '88) states that "The net effect of the center differential is to act as a power-management system, transferring engine torque away from the end that is slipping and to the end with greater grip; as much as 90 percent of the torque may be shifted to the front or rear as required. This is done actively, quickly and without the occupants of the car ever being aware of it."

Another interesting aspect: EPA figures for the iX are 17/23 and for the iX 18/24. One might expect more of a penalty for the AWD, but I recall Audi actually advertising that their Quattro system decreased overall fuel consumption because a driven wheel imparts less drag than a rolling wheel over about 20mph. I've never seen BMW discuss this issue or expliot this in their adverstising.

In it's stock form, the iX understeers somewhat more than most BMWs, is 0.4 seconds slower than an ordinary E30 from 0 to 60, and 0.3 seconds slower in the quarter mile. The rear axle ratio is changed slightly (3.91 vs.3.73:1) to minimize the effect of the added weight on acceleration. Car and Driver specifically notes that the iX stops 13 ft. shorter than an 325is, probably due to wider stock tires (205s vs. 195s). With the few mods that I've made, I picked up 1.4 sec 0-60 and 7 sec. on a two minute lap around Pueblo, Colorado's track.

Although the iX does not have enough power to break the rear end loose in 3rd gear, the AWD system does provide some advantages when the car is 4 wheel drifting through a turn near the limit of adhesion. At the point where a the
driver of a rear drive BMW would have to lift off the throttle slightly and countersteer, its likely that an iX would allow the driver to stay on the throttle. Power would be transferred to the front axle and the front wheels will pull the car through the turn. This is certainly the case on snow, ice, gravel, etc. and the same principle applies on dry pavement near the limit. It's just at higher speed and more exciting.

The basic technique used to drive the iX quickly is to "point and shoot". Upon entering a turn, aim to run over the apex, get on and stay on the throttle early, and allow the slight understeer to carry the car out away from the apex to the outside of the exit. Through turn keep the front wheels pointed in the direction you want to go and don't worry too much about where the rear end is going. This provides a high exit speed from the turn to carry you down the next straight. The iX and rear driver BMWs are great performers -- they are just different and need to be driven differently for maximum performance.

There's no significant difference between the 2- and 4-door models except the 4 door is maybe 50 lb. heavier due to the door hardware and window motors. The '88 iX seats provide lots of lateral support, are very adjustable, and have the extendable thigh support in the seat bottom. They were standard on all '88's (only 2-door iX's were imported in'88) and were optional in later years.

Until '90 or '91, the only colors availble were red, black, white and silver. Later, a few other colors were offered, including a beautiful dark metalic blue/purple. I've driven a quattro coupe and it does have a bit more power, due to the turbo, but there is no way I'd buy one. Personal preference and bias, perhaps, but they are just not built as well as the BMWs. From an enthusiasts viewpoint, the '88 iX is very desirable, but if you'd like lower mileage, an airbag, skibag and more attractive bumpers, go for a later model. In any case you'll have a car for all seasons, weather or not!

If you'd like to join the 325iX Registry, contact Gordon Haines at ghaines_at_entertain.com or write/call him at 11375 E. Vassar Dr., Aurora, CO 80014 (303) 750-9045.


<by "Rick Kjeldsen" <fcmk_at_watson.ibm.com>>

> What do you think of 325iX (89)?
> I would welcome some wisdom on this year and 4wd system.

The AWD system is very solid and reliable. The only "they all do that" problem is some leaking from the rear of the transfer case (the box behind the tranny where the front and rear drive shafts exit). It should be fixed if the leak is bad, and it can be expensive to fix (~$600 at a dealer). Otherwise the system is very reliable. It doens't seem to eat CV joint boots the way some 4WD trucks do. It doesn't seem to go out of allignment easily (the way my blazer does).
You get a little more cabin noise than the rwd version of the same car (from the AWD mechanicals) but it isn't obnoxious. Kind of a mechanical whirr. Actually comforting once you get used to it. The steering is a little heavier than the rwd version, but the handling is still crisp and precise. Once in a while you will feel the front wheels pull the steering wheel a little (e.g. driving fast over a bumpy road or driving hard through sharp curves. Generally when one front wheel looses traction and the other doesn't) but it isn't annoying, just different. There is none of the classic torque steer you feel with most front drive cars. Expect about 22 mpg, vs about 26 for the rwd version.


>BTW how do you like your iX model?

Love it. You can feel a little difference in the dry between it and it's 2WD siblings - it's steering isn't as light, the suspension doesn't feel quite as refined, there is a little more drivetrain noise, and every once in a while you can feel that the front wheels are driven as well. Don't get me wrong, it's still a blast to drive, but driving the 'es and the 'iX back to back, I can feel a difference. As you start to push the car to the limit you find that you can't upset it. You can't get the back end to come around, or get the car to start to feel out of control in any way. As you reach the limit of the tires traction, you gently drift to the outside of the turn, but it always feels very controlable. What is really fun is that as the road starts to get slick the car actually starts to handle BETTER! The heavyness in the steering fades, you start to be able to get the tail out a little (but just a little, and very controlable. Lift off the throttle and the car snaps right back into line.) By the time you get on "terrible" slick roads, the car feels as at home, as tossable, as confident as my 'es does in the dry. You can really tell it was made for those conditions.
The road up to a place I like to ski in Vt is a 5 mile steep curvy hill. The summer speed limit is 35, 15 in the corners. Last time I was up there, the road was covered with 5" of new snow, and had not been sanded. It was late, noone else was around, so I decided to see how well the 'iX would do. I was able to very comfortably maintain 50 both up and down hill, curves and all! The car never once got unsettled. Stop in the middle of a steep hill, then floor it - the car accelerates hard up the hill. At some point the wheels start to spin if you push it hard enough, but you can't really tell it's happening. All you feel is a little vagueness in the steering, but the car still basically feels like normal, so you will be driving along very comfortably and controlably with all 4 wheels spinning! Go into a sharp downhill corner fast, lift off the throttle (the classic way to make a car spin), the car slows down - not even the begining of a spin. Do the same thing again and hit the brakes, the car drifts a couple of inches to the outside, but otherwise behaves perfectly normal. To get the rear end out, I had to come around a curve really fast and floor it half way through. The tail would gently come out, very controlable, and as soon as you lift off, it snaps right back into place. There is basically NO WAY to get into serious trouble with this car without trying hard.
Sorry to rant and rave, but this is my first winter with it, and I'm more than impressed. It's the most amazing winter car I've ever driven (btw I own a 4x4 Blazer, and have driven 4wd Subaru's - never an Audi though).

>I would like to get one but im leary of the parts avalibilty.

I don't think you have much to be worried about. Most wear items are either identical to other E30s or easily avalible in the aftermarket (as well as at the dealer). The dealers also seems very aware of 'iX's, have their specific parts, etc. I've done a fair amount of work on mine since I got it and have had no trouble. The only problem I've had is that many people arn't aware there is a AWD BMW, so you have to make sure you point it out to them. For example, I got the car aligned, and they used the 2WD specs (which are quite different).

>Are they fragile??

Not at all. Typical sturdy BMW drive train. I looked at them at car auctions for about 9 months before I found one I wanted and didn't get out-bid on. I probably checked 30 or more. The only drive train problem I ever saw was a leak from the seals on the output shaft of the transfer case. About 50% of them seem to have it. Not serious, but apparently expensive to fix ($600 or so).

>And are thier alot of x model parts only on say the engine etc??

The engine is identical except for the cooling system and oil pan. The frame is slightly different (front shock towers reinforced and more upright). The rear drivetrain (behind the transfer case) is identical. There are some minor changes in the ABS system to make it work with the AWD. The fuel system is different to account for the lower gas mileage (bigger gas tank, repositioned gas filter). The front suspension is, of course, beefier. I believe the brakes are different, but not much. That's about all I can think of - besides the transfer case and front diff, of course.

There arn't many advantages to the 'iX if you live where it seldom snows. It's a little better in the rain, but you also loose a little compared to the 2wd versions in the dry. But if you live in snow country, it's the best winter car you can find.

FWIW,
rick
'87 325es
'90 325iX


<by wellman_at_epas.utoronto.ca (Barry Wellman)>

The 325iX basically performs like a regular E30 325. There is 4-wheel drive, but it is rear biased, (2:1, I believe) so the handling is more or less similar.
The differences are nice though:
... snip ...
3. You can get away with all-seasons in a great many conditions. (I have been running all-seasons for 4 years in Toronto, including not bothering to shovel my garage entrance, and just plowing thru 6 inches.)

Negatives?

  1. It's obviously more expensive.
  2. It may be a bit slower in straight-line acceleration.
  3. Its turning circle is a bit wider.
  4. You have to be a bit careful in shopping for wheels because the offset is different than the regular E30. A few other parts are different. (see below) ...

For a list of different parts & other 325iX lore, you should join the 325iX registry, run by Gordon Haines, Aurora, Colorado. ($5/year in US for newsletter; give him $7 from Canada & $10 from abroad to cover postage.) I don't have Gordon's number available right now, but if the FAQ maintainer contacts me, I will send it to him.


15.1.3: 323
From: "Hoffman, Larry" <lhoffman_at_seckenheim-msmail.army.mil> Date: Mon, 18 Dec 95 08:41:00 W

Ref: John Echohawk's questions about 323i

A 82 323i is the same body style as a 320i (E21) or 318i (E30), but with 40 or so more horses. The engine is an injected, 2.3liter, 6 cyln ("baby six"). Basically the cars were hot rod versions of the E21 & E30, and were not officially imported to the states. The E30 version first appeared in '82.

I have a 1982 E21 323i. It's a good handling, adequately powered car. Top speed is about 125 with the OD 5 speed. I think the original HP spec was 146HP. 0 to 60 is probably around 8 seconds. Comes with vented front disks & solid rear disks. 4 or 5 speed. The following were options: sport seats, sport 5speed, limited slip diff, ac, power steering, and more. The E21's came with dual exhaust. The E30's had single exhaust w/twin outlets.

Many if not most parts are the same as the 320i & 318i. All parts are available one way or another. (Keep up with the digest & join a BMW club.) The motor compartment is probably less crowded than a 325i. I think the 323i is a good buy at under $4000. Your mechanic may have been trying to "protect" you from buying a gray market car. Due to the limited availability of the 323i in the states, ownership will be rewarding &, at times, taxing. What's it worth to you to have a car that's a bit different?

In Germany, the cars are plentiful. Used parts are cheap. New parts from aftermarket sources are cheap. Parts from BMW are not cheap. I enjoy my 323i. It's definitely not underpowered. It's kinda special. It's a car guy's car.

Larry Hoffman
82 323i (Opal Grun Metallic)


15.2: Body
15.2.1: Water Leaks
(by Rick Kjeldsen: fcmk_at_watson.ibm.com)

Water on the (usually passenger side) floor in an E30 is often caused by a clogged air plenenum drain hose. There is a large air plenun at the base of the windshield that takes air from the air vents to the heater core in the center. There is a drain on the passenger side that drains water that comes in the vents out into the engine compartement before it can soak in past the gaskets where the heater core punches through the firewall.

The easiest way to find it is from the engine compt. If you have a 325 (6 cyl) follow the plastic "tube" that holds the plug wires back toward the firewall. If it were long enough to touch the firewall, the place it would touch you will see a 3" by 1" by 1/2" rubber hose comming out of the firewall and pointing down. That is the drain that gets clogged. You can usually clean it by squeezing it on the sides, but if it's badly clogged, you can take it off and clean it out. If you have a 318 or M3, find it by looking at the very inside edge of the battery tray on the firewall.

The trunks also leak occasionally. This is usually from old seals around the rear lights. Fix: remove and caulk with silicone. It's also a good idea to open up the drain "eyes" in the floor of the trunk. They are little 1/2" slits with the front pulled down and/or the rear pulled up (so water won't blow in but can drain out), and they often get plugged with undercoating. Find them in the bottom of the spare tire well, and in each well on the side of the trunk.


15.2.2: Tucking in large front bumpers

(NOTE, this applies to the large 5mph silver bumpers on pre-89(?) E30s)


for anyone who has an E30, don't know if this applies to any others, and want to shrink the front diving board, here's what to do. There is no need to drill out the bumper shocks, nor replace them with 89-91 shocks which I was about to do. Instead,
>remove bumper
>remove shocks
>loosen lock nut at the opposite end of shock about 1.5"s >while holding shock body, turn the mount end clockwise and you'll magically see the shock length decrease. You can keep turning until it bottoms. >align the mount so that it will be vertical after the shock has been replaced and tighten the lock nut.
> mount the shock, you will have to fiddle with the play in the shock mount to the car in order to achieve the correct height from side to side so that when the bumper is installed there is no gap along the top. >actual time 20mins to do. This is a good time to check the turn signal connections for corrosion, apply lithium grease here. THIS WAS SO EASY AND THE APPEARANCE IS SUCH AN IMPROVEMENT
15.3: Engine
15.3.1: Adjusting valves

There is a good description in the E28 section (14)


15.3.2: Transfer pump

(intro)
Early E30s have two fuel pumps, a "transfer pump" in the fuel tank which feeds gas to a high preasure pump in front of the left rear wheel which in turn curculates gas through the fuel injector rail. The transfer pump helps avoid problems like vapor lock. When it fails you may get symptoms like erratic idle, hard hot starting and a noisy main pump, but the car will generally still run.


Testing the Transfer pump:


(by Mark Rubin: markr_at_phineas.ent-img.com)

> If your MAIN pump is buzzing, you probably have a dead transfer pump in > your gas tank ..

A "buzzing" noise *is* the symptom. Two different mechanics have told me the main, above-the-tank, high-pressure pump won't last long without the transfer pump feeding it.
Guess I have some kind of rust/goo/contamination in the tank, and it's clogging the pump or filter or something.


(by Jim Conforti: jec_at_us.dynix.com)

Here's how I determined that my transfer pump was gone...

First .. main pump is making loud buzzing sound ..

Second .. Access the transfer pump, borrow stetoscope from Nurse Wife

Third .. bypass fuel pump relay and listen to transfer pump ..

Now you WILL hear what sounds like the xfr pump working, but it is really just a column of sound from the main pump, up an hose of incompressible fluid (gas)

So ..

Fourth .. Listen to the xfr pump area while disconnecting and reconnecting the

xfr pump connector (smaller 2 pin job) .. hmm .. NO CHANGE in sound Which means ..

DER PUMPEN IST TOD


(by Rick Kjeldsen: fcmk_at_watson.ibm.com)

Noise isn't always accurate. I've seen a transfer pump which "works" (i.e. runs) but doesn't pump any gas. The only sure check is to pull the hose from the transfer to the main pump, bypass the fuel pump relay to provide power to the pumps (the pumps only run when the engine is RUNNING, not when just the key is on) and see if the transfer pumps pumps gas (you may want to remove the connectors to the main pump when you do this so it doesn't run dry).


Changing the Transfer pump:


(by Jim Conforti: jec_at_us.dynix.com)

Simple job, 15 minutes max ..

Thanks to all the tips ;)

BTW, I used a handivac to cleanup all the dust on the top of the tank, before opening anything ..

Here's what I did .. (just for posterity and others who may have to do this)

  1. Remove lower rear seat cushion, and remove access cover .. clean up dust!
  2. Disconnect 2 sets of wires, 1 for sensor, 1 for pump
  3. Remove 2 orig. clamps (with diag. cutters)
  4. Remove 4 nuts and washers from sensor ..
  5. Slowly remove sensor to avoid gas mess ..
  6. Remove 2 hoses from xfr. pump and rotate and remove pump

Note: once you have "unlocked" the pump, you'll have to turn it around

a bit to remove the pump from the gas tank ..

7) Reassembly is the reverse, using 2 new hose clamps and 2 new o rings ..

1 is included with the pump, and the second fits on the sensor and costs 3.00 (big deal) .. don't forget to pry out the old sensor o-ring which fits into a recess under the sensor bolt flange, around the sensor body tube .. use a paper clip ..

I detailed this for 1 main reason, note that the best way to make sure that nothing falls into the tank, is to make sure that nothing is NEAR the tank opening that CAN fall in (like nuts, hose clamps .. etc ..) :)

OH, AND BTW .. a bad transfer pump DOES affect idle quality .. once I replaced the pump .. I restarted to check for leaks .. it took about 15 sec. for the buzzing to stop as the system assumed proper pressure ..

Then on the test drive, my idle now stays ROCK steady and smooth ..


An aftermarket transfer pump


(by Sam Chien-shin Lin: sam_at_cmd.com: edited)

I paid $29.48 for a BWD P1 pump and $1.99 for a pack of hose clamps and headed home.
BTW, the dealer doesn't sell the strainers separately - YOU HAVE TO BUY THE WHOLE PUMP!!! Pep Boys sells a BWD F4 strainer for $4.12 which fits nicely on the VDO and the BWD P1 pumps. It is a different design from the BMW part, but the fitting is the same, and it appears to have more surface area than the BMW part, so it should flow better. Anyway, it's 70 micron polyester mesh.
The hardest part of the kludge was popping the rivets that held the positive wire and the brass negative strap onto the old VDO pump. Looking carefully at the VDO unit, I noticed that the mounting bracket had an outline around it, which would leave just enough extra plastic to clamp on my hose clamps. I got out my hacksaw to cut along the outline and used two hose clamps to clamp the bracket onto the Vega pump. After some fiddling, I was able to adjust the positioning so that the wires would reach and the short rubber connecting hose would fit. Using the screws supplied w/ the pump, I connected up the terminals and Voila! Done! When I tried to install it, I ran across an unpleasant surprise...the hole in the fuel tank is such a tight fit that the hose clamp screws wouldn't clear; I couldn't get it into the tank no matter how I tried. Back to the drawing board... I had to throw away the mount I cut out of the old pump, was too thick to fit into the fuel tank. Finally, I got a short length of fuel line hose and slipped it over the fuel return tube (for shock absorption and traction) - the fuel return tube is what the mount/negative terminal is welded to, and then secured the pump to the hose-covered return tube with two large nylon wire ties (the zip-on type). It might not sound secure, but I pulled on it hard, and it was firmly secured. This time, it fit into the tank w/ room to spare. BTW, the later models do away w/ the transfer/main pump setup, and have only one pump in the gas tank.


15.3.3: Early twin cam fours' coolant leaks
From: Jim Newman <neji_at_mbari.org>
Date: Thu, 12 Jan 1995 18:10:22 -0800

According to both an independent BMW repair place and a dealer here in Monterey (CA), early twin cam 1.8 liter fours, as in 1991-1992 US 318i and 318is models, have a propensity for losing their coolant catastrophically from between the head and the block.

As described to me, there is an O-ring that seals a coolant port from the block into the head, forward end. Normally would be within the head gasket, but for some reason they used an O-ring. Corrosion in the head's aluminum, under the O-ring seat, can eventually allow coolant to get by the O-ring, resulting, naturally, in loss of coolant. The BMW dealer says to expect it every 50k miles! It may be visible as a trickle off the right front side of the engine before things get too far along, but it sounds like most people find out about it the hard way.

BMW changed the design in 1993 to fix this, according to the local dealer. And apparently BMW NA will pay part of the cost of the repair.

The cure is to remove the head, fill in the corroded part with epoxy goop, clean it up and put it back together. $700 at both the dealer and the independent shop where I learned most of this. This should make recurrence less likely (less metal exposed to rot away), but it's not a guaranteed permanent fix.

The best prevention is to make sure coolant is changed regularly, which keeps down the acidity of the coolant, and thus the rate of corrosion. I've heard of well maintained examples of this engine going 100k miles with no trouble.

Jim Newman


15.3.4: Small six (M20) head bolts
From: GToyama_at_aol.com
Date: Tue, 25 Jul 1995 16:59:08 -0400

325i engines, up to about April '89, came with hex-head cylinder head bolts; after this the engines came from the factory with Torx-head bolts. Easy way to ID is to look from an angle thru oil fill hole. If you have hex type, replace them ASAFP with Torx head bolts. This does NOT seem to be a mileage- or hard-driving-dependent problem. Many 'i' engines, my '88 included, suffered head bolt failure, where the head of the bolt snaps off and becomes lodged between a cam lobe and the head casting, puching a hole in the head (All I need is a...) and buggering up the cam. Ugly and expensive, mostly both. I understand the bolts can be replaced and torqued one-at-a-time without disturbing the head gasket; makes sense, but I can't confirm. Don't know if BMW will cover repairs outside of warranty; this is the one time I wish I HAD taken the car to a dealer...

FYI, my particular scenario: easy driving, no stress. Low coolant light comes on without warning, and with no untoward noise. I stop, no outward leakage, no hoses damaged. Run engine, add water. Add water, add water, hmmm, rough idle, stall, restart, no power. Water must be going somewhere; check oil, looks like chocolate milk. Damn! Call AAA.

Replacing these bolts is also a good idea for eta engines, as I understand BMW used the same type hex bolts for them.

A CAVEAT: If you decide to replace the entire engine as I did, try to stay with the same production year, or rebuild the one you have. I bought a used '90 2.5 liter engine for my '88. Figured same model, same engine, etc. Somewhere in between, tho', there are differences, both in throttle body hoses to the brake booster and in the engine wiring harness, although the connectors appear same. My shop went nuts trying to get the proper hoses to fit the throttle body. Then, not aware of the one different wire in the harness, went nuts when a wire fried upon startup. After spending about a week staring at schematics, they were able to kluge the wiring to work. It's run great since, but I wouldn't want to do it again.

Happy Bimmerin'!
Banzai Bimmer :-{)


From: reb_at_oix.com
Date: Thu, 9 May 96 06:46 EDT

>
>I've had some experience with these. When I put the motor from an '87 325i >into my 528e I had a lot of dealings with Peter McHenry (I hope thats the >right name...) who is widely regarded as "the" expert on BMW small six >engines. He told me that before I even start the engine I should replace the >head bolts if they were the standard type. You can look into the oil filler >cap and see the head bolts, if they look like they take an allen wrench you're >OK, otherwise REPLACE THEM SOON!
>

Good advice, THEY do break!!!

>The replacement bolts are Torx head type and designed to stretch. The older >type had a nasty tendency to snap the heads off, causing major damage. >
The TORX bolt is a stretch bolt and can only be used ONCE, that is if you take the head off again later on, they SHOULD be replaced again.

>Peter said that I didn't need to replace the head gasket or remove the head at >all. Just replace the head bolts one at a time, so the others remain torqued. >This would be a good time to replace the head gasket if you think it might >need it in the near future. (good time to adjust valves, too) >

Yeah, that what the Service Info says, but think about it, when the bolt is removed there is oil that may "dribble" into the bolt hole (threaded part) if this happens and you start torquing down the bolt, there will be a hydraulic lock and possibly damage the block. If you do this procedure remove the old bolt, spray hole with brake cleaner, blow out with compressed air and check the hole with an inspection lamp to make sure the hole is dry.

>The local dealer said that they had not heard of this but were 'surprised' >that they changed the bolt style (yeah, right). Then about six months ago I >saw an iX in the shop getting some serious engine work done. I asked what >happened to it and they said that a head bolt had snapped (surprise!) causing >water to mix with the oil (bad) and the owner drove it home and then to the >shop (REALLY bad).
>

The head of the bolt breaks off and the camshaft punches it through the cyl head....OUCH!!

As for the dealer not knowing this.......tell 'em to read their technical info......

>If you have one of these cars it is in your best interest to change these >bolts. It is inexpensive (<$40) and only takes about an hour to do. You will >need a good Torque wrench and a Torx bit (I forget what size). >

You will need MORE than a torque wrench to do these bolts, you will also need an angle torque gauge, and there is no substitution for angle torque (others may/will disagree, no one bolt has the same elasticity) anyway here are the specs:

Step 1 30Nm torque

Step 2 90* torque angle

Step 3 90* torque angle

No setting time
No warm running time

Hope this helps

>>>>>REB<<<<<


From: Doug Donsbach <dld_at_Symtec.com>
Date: Tue, 21 May 1996 14:46:28 -0400 (EDT)

Sean Thompson wrote:
>
> I have to do the head bolt switch and have a question' how does one > accurately determine the 90 deg after torquing the bolt to 22 ft/lbs(from > bently)I am assuming this is pre-loading the fastener based on it's known > strength. I also think that the angle measurement is important to have as > accurate as possible. Am I correct? what is the tool used in addition to the > torque wrench?what would the dealer use? TIA >
This is done in two different modes. First you use a conventional torque wrench and torque the fastener to the spec'ed torque, in this case to 22 ft/lb. Then you set the torque wrench down and go into angle torque mode.

This mode uses what is called an angle torque gauge to rotate the fastener through the spec'ed angle, in this case 90'. This can be done by eyeball but to be really accurate you should buy an angle torque gauge. I've seen them at Pep Boys, by Lisle I think, but lots of places carry them. The angle torque gauge uses a flexible cable to provide a fixed reference to a simple dial. The dial is zeroed and the wrench is turned until the pointer reaches the required angle. Note that the gauge includes no wrench or socket - you will use a breaker bar and a conventional socket with the gauge.

I think the factory specs an angle torque to help reduce torque errors due to (1) poor torque wrench calibration and (2) friction present in the fastener threads and the face of the fastener on the washer or mating surface.

Doug


15.3.5: 'i motor oil leak
From: RODDHOT_at_aol.com
Date: Tue, 28 Nov 1995 17:38:00 -0500

Owners of 325i & M-3 cars with oil coolers (It's tucked behind the front air dam) BEWARE ! there is an inherent problem with leakage from the oil filter head. Previously the only fix was to buy a new filter head for $135. Now a repair kit is available under part # 11-42-9-059-338 for only $4.83. This repair is also covered under SECRET BMW Warranty. Have your dealer refer to service bulletin # 11-09-90 dated January 1991.There is a fair amount of labor involved & is a MESSY job. try to get done under warranty.


15.3.6: ETA head job
From: Larry Schuette <schuette_at_ait.nrl.navy.mil> Date: Mon, 13 Nov 1995 09:57:08 -0500 (EST)

How to do a Top end job on a Eta engine.

I finished the top end job on my 83 528E, and it made a real difference in how the car runs. With 93K on the engine, I had the exhaust guides and all the seals replaced. The cost for grinding the valves and the valve seats, milling .003" off the head, and replacing all the seals, and the exhaust guides was $250.00 at the local BMW speciality shop. They also cleaned it up with a walnut bead blast. My exhaust ports had coked up so that I only had about 70% of my exhaust port area left.

If you've got 100K on yours you may want to remove one of the exhaust manifolds and take a look, you can easily clean out the coke with the head on the block.

My cost was $250.00 for the shop, and about $200.00 more for the timing belt, tensioner, gaskets, copper nuts (exhaust), head gasket, seals, and head bolts. The only special tools you need are a E-14 Torx socket for the head bolts. It takes about 5 hours to take it apart, and another 8 to put it back together. The extra time is spent waiting for the engine to cool off so that you can adjust the valves again.

Other interesting, well known facts tidbits.

According to the local BMW dealers' mechanics and the guys at the speciality shop the following is lore (sure was news to me). First, early Eta engines have weak heads. They were redesigned after 10/83 to correct for a design flaw wrt the cam bearing journals. Early heads tend to crack (look for frothing in the valve area -- "like a milk shake"). Heads with the BMW logo and 4 "."'s around it are o.k., they should be stamped on the with a date after 83.

(Naturally, mine is stamped 10/82 :() ) In an effort to cheer me up, the machinist said "well, they weren't all bad, be sure to run good oil though" (great).

Secondly, the 6 cylinder engines because they are fairly long, tend to suffer torsional flex problems. This is true especially in early engines that have all the freeze plugs. This problem shows up in excessive oil consumption in cylinder #6. (thus check this one when buying a used car), The compression will be fine (it's an oil control problem). The solution is to loosen and then retighten the bolts connecting the block and tranny. Factory is like 100ft/lbs, they recommend 45 ft/lbs.

I miked my bores, and the first 5 were within 1/2 a thousandth of being round. Sure enough, #6 was 2 thousands out of round.

Larry


15.3.7: Idle problems

(NOTE: The idle control unit described controled the idle on early E30s using Motronic 1.0. This covers up to about '87. It does not cover the 'i)


From: Jim Conforti <jec_at_us.dynix.com>
Date: Tue, 27 Dec 1994 11:40:08 -700 (MST)

The Idle Control Unit (or module, hence called ICU) is an analog closed-loop controller based on some op-amps that outputs a PWM (Pulse Width Modulated) signal to the Idle Control Valve (called ICV) ..

A current of 0mA will cause the ICV to be fully open, and a current of about 500mA (approx) will fully close it ...

The ICU gets the following inputs ..

  1. 12vdc [power]
  2. Ground
  3. RPM Signal [from coil primary]
  4. Idle Switch input
  5. Auto Trans Park/Neutral Input
  6. Engine Coolant Temp Switch input (closes at 45degC+ coolant temp)
  7. Air Temp Switch (on firewall, behind battery; closes at OdegC- air temp)

The output is a two wire ckt. to the ICV ..

The PROPER operation is a follows ...

AT in ANY gear, 700 rpm

AT in P/N or MT vehicles ...

Engine cold (< 45degC) 950 rpm

Engine warm (> 45degC) ...

Ambient Air Cold (< 0degC) 850 rpm

Ambient Air Warm (> 0degC) ...

A/C ON 850 rpm

A/C OFF 700 rpm

Get either a Bentley, or a factory (318i and M3) service manual and check all of the inputs to the ICU ... you'll have to look close to see the Idle Switch value, as it is only there for a split second unless the engine is running .. both Bentley and factory manuals have good ICU input tests ..

Next check for proper setting of the throttle plate position ... it should be closed almost completely, a few thousandths is the proper opening! ... also check for vacuum leaks ..

You can check the ICV with a 9v battery .. if you remove the ICV and connect it to a 9v battery, it'll snap closed if O.K. ...

BTW, you DO have the silver metal ICV, and not the black plastic one, right?!?

If you have found nothing else, then it is a good bet that the ICU is dead or dying .. NOW .. if you are brave, you might be able to fix it!

Remove the ICU, unplug it, and bring it inside .. open the case and the connector (12 pin) will slide out with the 2 small circuit boards attached

You open it up by prying the connector out of the end of the case with 2 small flat-bladed screwdrivers ...

If you look at the circuit board, you may see a burned area near a large transistor on the board that is directly connected to the 12 pin connector

Check those burned traces with a multimeter & magnifing lens, chances are one is cracked/fryed ... use a small piece of wirewrap wire to bypass the burned area, from transistor solder pad to the next solder pad on down the line ... (usually, this is one of the 12 "connector pin" solder pads)

This MAY fix it, but if not, get yourself a new ICU AND ICV .. you should change them BOTH at the same time ...

The last hope, is that one of the connectors in the harness side is a bit stretched out and is not making good contact with the pins on the ICU ..

If you ARE REAL CAREFUL .. you can slide the back off of the 12 pin harness connector and AFTER NOTING THE POSIION OF EACH WIRE BY COLOR IN RELATION TO the INDEX PIN (plastic) .. you can remove the front of the connector, and using needle nose pliers GENTLY crimp/close/tighten each of the 12 female socket pins .. replace the connector front, assuring that the each wire is in the correct place in relation to that INDEX pin, and put the back of the connector back on .. hook it back up and try it .. a lot of times, the connector is loose, and that's the ONLY problem ...

Jim Conforti


15.3.8: Timing Belt
(by Rick Kjeldsen fcmk_at_watson.ibm.com)

The E30s with the "baby-six" engines have a belt driven camshaft (the 4 cylinder E30s don't). These belts have limited life, recomended change intervals are 60k miles. Consequences of a broken or stripped belt are serious - pistons and valves hit and at a minimum the head will have to be rebuilt. Some people have reported broken belts at less mileage, so some people recomend changing the belt sooner (50k or even 40k), especially in a very harsh environment like the desert (extream heat seems to shorten life).

I suggest you change the water pump and tensioner pulley while you are in there. Water pumps often don't last two belt changes, and labor to get at the pump is pretty high - about the same as changing the t-belt. The tensioner usually doesn't fail, but it is cheep, so changing it is good insurance. Other stuff that is good to change at the same time are the camshaft seal (behind the distributer), any belts and hoses you suspect, and engine coolant. The plastic radiator hose hanger (part # 11-53-1-714-433) and two "7-clips" (part # 11-14-1-716-134) often are brittle and break, so are good to have on hand.

The job is pretty basic DIY, but because of everything involved, it is time consuming. Everything is well marked, so as long as you are careful, there is little danger of reassembling the engine with the cam rotated wrong or anything major. The full changing procedure is to long to go into here, refer to a good manual such as Bently.

Some hints: pulling the radiator makes things MUCH easier to get to, and often less painful. I take off the hood as well (easy, just don't drop it!). The fan can be tough to get off - especially if the previous servicer put it on more than finger tight (that is all it needs as the force of driving the fan tightens it up plenty). Remember it is reverse threaded onto the water pump. The bolt can be tough to get at. BMW sells a special thin 32mm wrench for it. I just pull out two of the 4 bolts that hold on the waterpump pulley, and that gives me plenty of room to get a standard wrench on it. On later cars (after around '86) the crank pulley/damper is held on with 6 bolts, but is such a tight fit it can still be tough to get off the crank. Just keep tapping and wiggling it, it will come. I've heard early cars make you take off the big crank nut to take off the pulley.


15.4: Suspension & Steering

15.5: Brakes

15.6: HVAC

15.7: Electrical
15.7.1: Jerky Wipers

Your wiper motor has a bit too much grease in it and it has hardened up on the "park" contacts in it. Sounds complicated, but it's actually (as far as BMW's go) not TOO hard to fix.

The story is: the wiper motor has contacts in it that make it continue to run, and park. These contacts close on a metal segment on the plastic gear that drives the shaft coming out of the motor (the motor itself is at right angles to this). If the housing had too much grease in it (which was fairly common, at least on my year), or the grease has hardened up.. the contact tend to skip a bit, causing the jerky action. The big hint is that it only occurs in the intermittent mode (which you describe).

TO FIX (Two choices):

  1. Go to dealer, sell left arm, buy new motor.
  2. Remove motor and clean out grease, regrease.

ssuming you may want to tackle #2.. here is how it's done:

  1. Remove the motor. I'd disconnect the power connector going to it first (it will try to park otherwise if you accidently rotate it, perhaps taking a finger or two with it). On my 535 - it's behind the cowling for the fresh-air intake for the heater - don't have a clue where for a 3er.. remove the nut (and washer) holding the linkage to the motor, try to prevent it from turning while you remove it. The arm connecting to it is splined, but removes fairly easily (a good tug). Remove nuts/bolts holding motor in vehicle. Walk it to your workbench.
  2. Disassemble: The contact you want are behind the light aluminum plate that covers the big gear (this will be fairly obvious).. on mine, the plate was held on with mashed over aluminum studs. Right next to these studs were holes through the plate and corresponding holes into the housing.. sorta looked like these could be tapped to take a few screws for reassembly (CLUE!).
  3. Repair it: Drill off the mashed over aluminum heads of the studs (1/4" bit works fine). The cover should remove easily. You'll find lots of nice brownish grease. Clean the contacts (attached to the cover) and the face of the gear where the metal segment is). Regrease lightly with a white lithium grease (at least that's what I used)..very lightly!

While apart - tap the holes in the aluminum housing - I *think* I used 4-40 American (looked about right, and I had the tap and some short 4-40 screws, but it might have been 2-56). Try to keep tap filings out of the housing (grease on the tap helps a lot).

4. Reassemble: Put the cover back like you found it and screw it back together. Reinstall motor in car. Align the motor by starting it once WITHOUT the wiper arm attached and letting it go to the park position. Once it's aligned, refasten the wiper arm in the correct parked position (try NOT to turn the motor while tightening the nut holding the arm).


15.7.2: Erratic blinkers
(by Rick Kjeldsen: fcmk_at_watson.ibm.com)

>Within the last 2 weeks, my left side indicators have been misbehaving. >Flashes real fast in other words..... I got out and checked the bulbs, >all of them work. The problem does not persist - it settles after some >indeterminate amount of time... Guess its a bad contact at some place

That is a classic symptom for a bad contact between the wiring harness and the front blinker assembly. You can get at it by removing the plastic cover in the engine compartement that covers the back of the headlights and reaching down into the bumper. You will find a plug with a rubber boot that plugs into the back of the blinker. Pull it off and on a few times to temporarily fix the problem. For a more permenent fix, clean the contacts and put some dielectric grease in there before you plug it back together. (you can get dielectric grease at most auto-parts stores)


15.7.3: Wiring fog lights to work with high beams

Instructions for E28 535i (differences for E30 at end)

There are two philip screws which attach the top of the fuse box (or power distribution panel as the book calls it) to the bottom of the box. Remove these two screws. You may have to remove the relays above the screws to get at them. Find and remove the fog relay (marked in the owner's manual and the Bentley). Remove the connector in the top part of the fuse panel (it's in the slots that you push the relay in) for the 85 lead on the relay (if you look at the bottom of the relay, the leads are labeled with the numbers 30, 86, 87, 85...so on). The easiest way to remove the connector is to use a very thin flat screwdriver and push on the back of the spade to push the little tab back into the spade so it slides out the bottom of the fuse panel. Drawing below:

| <-- thin screwdriver
|
______ |__________ top of fuse panel
|
|\ <-- push this tab in from above
| to slide connector out the bottom

Now pull the connector out the bottom of the panel by separating the top and bottom halves of the fuse panel. The halves do not separate much maybe 3 inches. Tape this connector up or use shrink tubing. You won't be using this connector again. The next step is to remove the connector of the 85 lead of the high beam relay (this is ground, you might want to test for such) in the same way but you will use this again.

Make a y connector with two leads to fit in the two slots you just removed the connectors from and the third lead to fit in the connector that was connected to the 85 on the high beam relay. Plug the y connector in (slots and the extra lead). Tape or shrink wrap the y connector to previous 85 high beam conector. All that is left is to plug in the relays and test the new feature (fogs on even with high beams on) and put the two halves of the fuse panels back together. TEST!! before putting the halves together.

Instructions for E30 318i (should apply to any E30)

Same as above except disconnect 85 on the fog relay and put the y-connector to the connector on the 86 of the high beam relay (this is +12v when the ignition in the run position) and the 85 lead of the fog relay.


The nice part of this rewiring is that it is entirely reverseable since no cutting is involved. I have seen as a Porsche mechanic too many car wiring systems destoryed by poor rewiring for extras and especially sound systems.

I have also wired my fogs to function as longs as the light switch is in the park or on position but that extra bit is more complicated than I can explain in this media.


15.7.4: Service Indicator Lights

For info on resetting or repairing the SI lights, see the General Repair info Section


15.7.5: Finding 'iC check-control relays
From: Matthew Hocker <hocker_at_waldo.com> Date: Mon, 24 Jul 1995 19:36:59 -0400 (EDT)

A while ago, I posted a request about trying to find the rear lights check relay, as mine had self destructed. Fortunately for everyone else with the same car as mine, no one else had lost their relay, so I had to do a little scrounging to find it. This relay is improperly marked in the Bentley book as being next to the power antenna, a fact probably true for hardtop E30s, but not for the convertible.

For the FAQ, the relay is located on the driver's side of the car, behind the trim for the backseat. That is, it's on the wall of the car, directly below the rear window of the car. Here's how to get there:

  1. Lower the convertible top and put the driver's seat forward
  2. Lower the windows (makes access easier)
  3. Remove the weatherstrip for the window by lifting gently to unclip it.
  4. Remove part of the door weatherstrip, just enough to expose the joint of the backseat trim.
  5. Remove the face for the rear speaker, and unscrew the two outside screws. The two inner ones are for the speaker, and should be left untouched.
  6. The panel should now be free. Pull it out and turn it to the back of the driver's seat. This helps by not requiring removal of the seatbelt.
  7. Disconnect the speaker.
  8. The relay is located behind the sheet metal, at the bottom. It is visible by the two screws and a corner of the wiring harness, through a small hole in the metal. Removal is simple, just unscrew, pull out, and disconnect. You may need to remove the seats, although I didn't.

I reconnected a new relay and was up and running in 20 minutes. Replacement of parts is the reverse of removal... ;) Seriously, it was a simple operation.


15.7.6: Installing 318 cruise control
From: David Manderscheid <mander_at_math.uiowa.edu> Date: Tue, 11 Jul 1995 10:25:41 -0500
Subject: 91 318is cruise control

A recent poster asked about installing cruise control on a 91 318is. This question has come up a number of times on this list and I have previously answered it in private email with the posters. This tiem I will post to the list. Cruise was not an option on this model and there is no BMW cruise that will work (eg the 92) according to both my dealer and the local independent shop. I had an aftermarket unit installed on my car and it works fine so it can be done. THe unit was 220 for parts and 3 hours labor to install. According to the shop (SIMPSON MOTORSPORT in Iowa City) it was a real pain to install. I can't remember the name brand of the unit but it was from North Carolina and has a dash mounted control unit (use the fog light switch spot) that looks pretty cheesy but has worked without problem for two years.

Dave Manderscheid
91 318is 37K


15.7.7: Fixing Erratic Clock (not OBC)

(NOTE: the following applies to the base clock/temp unit, not the OBC clock)


From: schoudhu_at_ccmail.abbotthpd.com
Date: 29 Jun 95 09:55:11 GMT

Fixing the sometimes blinking clock/temperature display on an E30

This could be due to a bunch of loose connections, but the one that seems to pop up a lot is one connector:
   _                                               ASCII DRAWING
  | |  .---------.                   .________     Side View, Exploded
  | |  |         |      _            |        |    =====================
  | |  |         |  *- | |           |        |    A- Front Plastic Panel
  | | [|         |     | |           |        |    B- Front of Housing
  | |  |         |     | |_          |        |    C- Rear of Housing
  | |  |         |     | | \         |        |    D- Plastic Handle attached
  | |  |  |      |     | |\ \        |        |       to the electronics bwd.
  | | [|  |      |     | | \ \D      |        |    E- Actual PWA with
  | |  |  |      |     | |  \)       |        |       electronic components
  | |  |  |      |     | |           |        |    F- 12-Pins, Male
  | |  |   \     |   __| |           |        |    G- 12-Pin Female Connector
  | | [|    --   |  |__| |-          |        |
  | |  |   / F   |  G  | |           |        |    *-  represent two of
  | |  |  |      |     | |           |        |        the four screws.
  |_|  |.________|  *- |_|           |________.
  A    B                 E                     C

This above is an exploded side view. I have found that the solder connections on the pins of the 12-Pin Female 'Molex' brand connector (G) were yellow, crusty, and had dried out a bit on one row. Well, this was just the amount of play needed to sometimes make or break a connection, causing the display to freak out. Instructions on how I did it:

  1. Remove (A) with tiny jeweler's screwdriver from dash of car
  2. Push in tabs with fingers ( one up, one down ) on the face of (B),

    and pull. The whole box-like unit slides easily out.

  3. Unplug the male connector that attached near the handle (D).
  4. Take the boxed unit to a bench.
  5. Use screwdriver edge to pry open (B) from (C). In pulling on the two

    sides, remember that (F) and (G) are really what is 'pulling apart' and diconnecting.

  6. Unscrew the four screws so that (E) detaches from (C).
  7. Examine how well (G) is seated into (E).
  8. Unsolder connector (G) from the board (E).
  9. Resolder connector (G) into (E), and re-assemble unit.

(: Easy :) You can replace the bulbs when you have the box open too!

Regards, Sy Choudhury 89.E30.325i.109K with non-intermittent clock :)


15.7.8: Adjusting Headlights
Here's what I found in a German manual for the E30s and it probably applies to the E36 as well.
  1. Park the car 5 meters back from a wall.
  2. Draw a horizontal line on the wall 5 cm below the height of the center of

    the headlight unit.

  3. Mark X's on the line which are as far apart as the centers of the

    headlights are apart on your car.

  4. Adjust the height of the beam so that the flat part of the pattern lines

    with the horizontal line (i.e. 5 cm drop for 5 meters forward distance).

  5. Adjust the lateral aim so that the "kink" occurs at the X's.

The fog light beam should drop 10 cm in 5 meters.


15.7.9: Killing the Key Gong
From: marshall.garrison_at_cccbbs.cincinnati.oh.us (MARSHALL GARRISON) Date: Tue, 30 May 95 20:13:00 -0500

OO> From: Jim Conforti <jec_at_us.dynix.com> OO> Subject: E30 Key buzzer/gong
OO> Pull the drivers side door switch by removeing the single screw ... OO> Note that there are TWO wires to the switch .. OO> One is the lights
OO> One is the key gong
OO> Removing the keygong one and insulating it works just fine .. OO> Be nice, and wiretie it to the remaining wire so it does not get OO> "lost"

The downside to my thought about tieing that wire into the seatbeltunfastened alert wire: then the gong would sound incessantly anytime the key was turned in the ignition and the seatbelt wasn't latched (instead of the door being opened) (Doht! :). Okay for driving around, but not for separate harness use at driver's schools or working on the car. At least it could be quieted by latching the seatbelt or using a spare seatbelt buckle. Probably way more hassle than it's worth though, compared to the simplicity and reversability of your suggestion! Thanks again!


15.7.10: Replacing OBC bulbs
I just replaced the OBC bulbs on my E30 on Sunday. Various views on the easiest way to get at them have been posted. I tried both the glove compartment and the center console methods. The glove compartment might be OK if you have hands the size of a 5 year old. The center consoleway is pretty good, only pain in the butt is getting the lower screws back in. I think you only need to get the right hand one out. I played around with a few bulb types as RS in all their wonderfulness, had a crap selection. Turns out the ones that work great are the 6V 100 mA ones, but I could only get them in screw in type. Just solder a couple of wires to them and they work OK.
I cannot believe BMW charge nearly 30 smackers for that tiny board. Cheers
Blair
[bulb ratings]

Blair, they are 6V, 85mA


15.8: Misc
15.8.1: Steel wheel center caps
(by Rick Kjeldsen fcmk_at_watson.ibm.com)

>I have an '85 325e with 14X7 steel wheels that I use for winter. >I would like to get some hub caps for the wheels, but I don't want the >$5- plastic jobs that the dealer sells... >Any help is appreciated.

I put steel wheels on my 'iX for the winter, and didn't want full hubcaps. It turns out BMW sells a small center cap that is about 3" across by 1.5" tall, nicely made chrome plated steel with the Roundel in the center. It is supposed to snap onto some wheels, I think. It doesn't snap onto the 'iX steel wheels (which I believe are identical in the center section to other E30 steel wheels), but the lug nuts fit over the wide flange at the bottom and hold it on very nicely as I've tried to draw here:

                        Roundel 
                           |
                           V
                     |---------------|
                     |               |
            ______   |               |   ______
           | Lug  |  |    Center     |  | Lug  |
           | Nut  |  |     Cap       |  | Nut  |
           |______|  |               |  |______|
           \      /__|               |__\      /
            \    /|_____________________|\    /                   
   __________|__|__/                   \__|__|___________
             |  |         Wheel           |  |

There is a small gap between the cap and the wheel. The cap doesn't rattle, it's held firmly, but water and dirt can get into the hub nut, so I filled the cap with a block of rigid foam which presses against the wheel and seals it.

All in all it works really well, and looks sharp (IMHO), especially with black wheels and lug nuts.

The part number for the caps is 036 13 1 127 230. I think they ran about $7.00 each (with the club discount at Hendrick BMW).

enjoy,
rick
'87 325es
'90 325iX


15.9: Performance
15.9.1: ETA Differentials
(by Harry Sidhu: 72130.3211_at_CompuServe.COM)

Various diffs that you can use in place of the 2.91 or 2.93 (ETA 325): 3.25 used in 9/82-9/84 533i,535i,635csi; 528e 3/87-12/87; 524td all. 3.46 used in 635csi 9/84 onwards; 528eA 3/87-12/87 3.73 325i,is 9/87 onwards
3.90 and 4.10 are also available but useless unless you have a 200hp motor with a 9000rpm limit.
All the above are referred to as "6 cylinder rear loading". The above 5 and 6 series diffs are identical to the 3 series diffs except for the axle flanges (slight difference in diameter) and the rear aluminium cover (different mounting point) both of these can be quite easily transferred off your existing diff. The flanges can be pried off with a large screwdriver or pry bar and the rear cover is fastened using 8 bolts. These are available for about 1/2 the price of used 325i diffs. The only problem is that relatively few of these were limited slip so whoever you are buying it from, make sure you let them know that you will only accept a limited slip and one that will fit. Remember that all these limited slips only have a 25% LS which translates to 45ft.lbs breaking torque, to get more you have to go to the aftermarket.
In my case they first shipped me a 84 318i diff. and then a 3.45 side loading diff before finally getting it right. (3.73 LSD). If anyone is interested, I have pictures and applicatons of all the BMW diffs that I can fax.


15.9.2: MCU switch settings

Note, this switch does not exist on all E30s, or even all 'e's


(by Harry Sidhu: 72130.3211_at_CompuServe.COM)

For all those involved in the quest for higher velocities, here are the settings for the MCU switch. Please remember that the settings are affected by the gas you use, what kind of carbon buildup you have on valves/injectors etc. so the settings I use may not work at all for you or may work better(hopefully).

The switch in question is light or dark blue (depending on year of manufacture) and to reach it you must open up the MCU and unfold the 2 boards in there. One of the boards has this on one of the sides. It is cylindrical and about 1/2'' in length. From the stock setting which is with the notch straight up, it can only be turned clockwise to achieve 6 additional settings which are listed below.

  1. Stock
  2. 3% increase in injector open time, no timing change
  3. 3% decrease in injector open time, no timing change
  4. 6% increase in injector open time, no timing change
  5. 3% increase in injector open time, 2.78 degrees retard
  6. 3% decrease in injector open time, 2.78 degrees retard
  7. 6% increase in injector open time, 2.78 degrees retard

I am currently using setting #2 with the CO on the air flow meter turned up a few turns (4). Next, I plan to mess with the spring in the air flow meter and also increase fuel pressure (soon as I find the right regulator).

The retard setting are useful for people with aftermarket chips who have pinging or detonation problems.

Remember your optimum settings could differ and make sure to note the stock settings so you can go back in case you start blowing black smoke out of the exhaust (too rich).

Again, these procedures are not looked favorably upon by most people.


15.9.3: ETA engine performance
(by Rick Kjeldsen, fcmk_at_watson.ibm.com)

Because of the engine's design, you are somewhat limited unless you get pretty radical.
A chip (Dinan or Autothority seem to be the best) gives a noticable increase in power and gets rid of some of the minor drivability problems - but they don't make it into a dragster ;-) They also increase the rev limit to about 5300, but you don't get much benifit out of that last 300 rpms. Shifting at 5000 gives me the best accel. A K&N filter will give you a little on the top end (>3500 rpms) and a very nice intake note at high rpms too. Really makes the car snarl when you wind it out.
Above 5000 RPMs you will drop off because of the cam. Rumor has it you can drop in an 'i cam and valve springs and get a nice increase. I have yet to talk to anyone who has done it yet. The rumor of dropping on a 'i motor head is garbage (kills compression, worse than useless)
The stock exhaust is the best you can do there. The big throttle body and air boxes you used to see around for it are useless too.

One of the best mods you can make for acceleration is to change the rear end ratio. Stock came with 2.76 ro 2.91 depending on the year. You can take that up to 3.25 (easy to get) without sacrificing much streetability. 3.75 (?) (from a 325i, so easy to get, too) gives you a lot of punch, but the 1->2 shift comes up VERY fast, and the car gets buzzy on the highway. Remember, it's torque that accelerates you, and the 'e has slightly MORE torque than the 'i motor, so you give it the same rear end and you accelerate just as fast! Even with a chip you won't have the RPMs of an 'i, but that doesn't matter as much on the street.

I run a Dinan chip with a 3.25 rear end (and small diameter tires on the track - equivalent to a higher diff ratio) and K&N filter. The car is much faster than stock, has better throttle response and a smoother acceleration curve. It runs about 300 RPMs higher on the highway, noticable but not annoying. Mileage is about 2 mpg lower, because the chip modifies the curves more at higher than stock RPMs and the diff puts me in those rpms more often.

If you want to get more radical, there are several builders who redo the 'e head, put in light pistons and flywheel and do things like that and end up with about 190 HP. Metric Mechanic has one that interested me very much for about $4000. Korman has several rebuilds for it but they tend to be more pricey. He used to race the 'e, so he does know the car. I have his suspension and I'm very happy with it. He also has a turbo for it, but I don't know any details. Drop him a line and have him send you his E30 325 catalogue (sp?).
Pete McHenry kind of specializes in the small 6 block. He has done some ETA rebuilds, but he doesn't recomend them. His argument is that you can do better dropping in an 'i motor (which you can build to higher power levels) or even the M50 motor from the E36 (185 HP stock, and easy to build to 250 HP +). The M50 only adds about 6 lbs to the car. I've seen the motors w/ low mileage for about $3000, and it will cost about $1000 to put it in. I think that is the route I'm going to go when my (150k mile) engine gets tired. Either swap is relatively easy because the blocks are the same, and you end up with a near stock configuration.


From: bthongsa_at_students.uiuc.edu
Date: Wed, 24 Jan 1996 20:50:01 -0600 (CST)

> I have noticed that in the 1988 year of the 528e series there are greater > differences. The cam shaft uses all 7 bearings, has larger intake and exhaust > valves and also uses a different exhaust system. The exhaust system looks like > it came off the 535. I was wondering if anyone knew what the difference is > between this motor and the motor on the following years 525i.

Ah, the 'super-eta'. Post- 3/'87 528es and '88 325s(not i or is) use this motor. It's basically a 2.7 liter, detuned version of the 2.5 motor found in the '87-'91 325i/is and '89-'90 525i.

The super-eta uses the big port/big valve head of the 325i/525i, but with a milder cam and weaker valve springs. The bottom end has a longer stroke crank for the extra displacement. Also, the intake manifold has extra-small runners to increase intake velocity (smaller than the 'i' motors, and smaller than the earlier eta motors).

This motor has more performance potential than the earlier etas. An 'i' or early eta intake manifold, 'i' cam and valve springs, and matching chip are what's needed to create what would basically be a 2.7 liter 'i' engine.

Ben


From: bthongsa_at_ux4.cso.uiuc.edu
Date: Tue, 21 Feb 1995 14:35:38 -0600 (CST) Subject: Re: e to i conversion

> > That's pretty much how it goes. The 'super' eta head is a > >325i head. Fancy that. :)
> > So you could also just swap intake, head and chip from > >a 325i. The 325e intake is smaller to provide more low-end torque > >for the eta motor.
>
> How sure are you of that info?
> The reason I ask is that I talked to Pete McHenry over O-fest, and > he said that the myth of putting an 'i head on an 'e engine is > hogwash. Apparently the geometry of the 'i head in combination with > the 'e pistons drops the compression so low that even running is a > problem. Performance is out of the question.

Putting a stock 325i head on a regular (pre-'87 or so) 325/528e is possible, but you'll suffer from really low compression. The 325i head is flycut (check out the pictures on the 2002 page -- yes, there are pictures of a 12 valve 325i head there) and has corresponding pistons with a funny dome-bowl top. The 325e head is not flycut, and the pistons are flat with a dish. Mating the two will provide for about a 7:1 compression ratio or so.

> I don't know if that applies to the "super-ETA" or not, but I'd > want to talk to someone who did it before I tried it!

As far as I can tell, the super-eta has special pistons that will mate with the flycut head. I almost got a chance to pick up a burnt super-eta cheap, but alas, it was tossed before I could get to it. I have this 325i head that is waiting for a suitable 2.7 block...... So I can't say for sure, but I think that the 325i head should work well with the super-eta block.

Of course, you could always just replace the e pistons with something suitable, and run the i head.....

Hope this helps,
Ben


From: bthongsa_at_ux4.cso.uiuc.edu
Date: Wed, 22 Feb 1995 15:14:08 -0600 (CST)

> >Putting a stock 325i head on a regular (pre-'87 or so) 325/528e is > >possible, but you'll suffer from really low compression. The 325i > >head is flycut (check out the pictures on the 2002 page -- yes, > >there are pictures of a 12 valve 325i head there) and has corresponding > >pistons with a funny dome-bowl top. The 325e head is not flycut, > >and the pistons are flat with a dish. Mating the two will provide for > >about a 7:1 compression ratio or so. >
> So can I assume that the super eta head is actually a "i" head (flycut head -- > what does this mean??), that is why it has the special pistons necessary. If

I _think_ so, but I'm not absolutely sure. Flycut means that the combustion chamber was machined so that the "edges" are rounded up. Hard to describe. Take a look at the pictures on the 2002 page, it's pretty obvious there.

> that is the case then I can take the head in my car 1988 528e and just replace > the cam and the valve springs to get a "i" engine with greater displacement?

Yes, this will work even with the standard e head. Just be sure to drill the extra oil passages for the cam.

> Will I have to replace the intake manafold and the throttle body from a "i" > engine or will the existing hardware be okay to work with the new cam?

It's not necessary to replace the manifold. In fact, for the 528e, I'd prefer keeping the eta manifold. Installing a 325i manifold will gain you some top end HP and breathing, but at the loss of some of the low end torque. The 325i throttle body wouldn't be a bad idea, though.

> I am also assuming that the chip in the ECU will need to be replaced, but how > will this setup deal with meeting smog emissions?? (I live in California)

You'll need the chip. Smog shouldn't be affected. You'll basically have a 325i engine, only with more displacement.


From: bthongsa_at_students.uiuc.edu
Date: Tue, 23 Jan 1996 20:01:20 -0600 (CST)

> There is a serious caution that anyone considering just doing the head and a > chip on an eta engine: the bottom end is less sturdy. It is not designed to > handle higher rpm use. The piston rings are of a special low tension type > and the bearings are softer, both intended to reduce friction. But they wear > a whole lot faster when you rev them up. There are also other differences > which leave the eta engine not to well suited for higher rpm use.

As far as I've seen, the bottom end of the eta is really no less sturdy than the 'i' motors. True, it doesn't take high (6000+rpms) revs as well as the 'i' motors, but that's more of a function of the extra stroke length and weaker cast iron crank. But, that's what the 524td crank is for -- it's forged and drops in. The usual chips used in e to i conversions have a rev limit of 5700-6000, though, so the bottom end doesn't really pose much of a problem.

I don't recall offhand, but I don't think the eta uses different bearings from the 2.0/2.3/2.5 'i' motors. Besides, bearing material doesn't really influence friction much on journal type bearings.

> Can anyone more technically astute on the eta engine go into further detail > on the low friction, but consequently quicker wearing aspects of this motor?

The main area where the eta motor is 'low friction' is the valvetrain. The eta cam only has 4 bearings, as opposed to the 7 on other small-6 motors, and the valve springs are considerably softer too. Other than that, the lower revs inherently brings about less frictional losses, and the tall gearing/high load reduces pumping losses by forcing the driver to use a larger throttle opening for a given speed.

Ben


From: read_at_engr05.comsys.rockwell.com (Pete Read) Date: Wed, 24 Jan 1996 07:57:39 -0500

Barry Burr asks:
>There are also other differences which leave the eta engine not >too well suited for higher rpm use.
>Can anyone more technically astute on the eta engine go into >further detail on the low friction, but consequently quicker >wearing aspects of this motor?

Ben answers:
>>As far as I've seen, the bottom end of the eta is really no >>less sturdy than the 'i' motors...
>>The main area where the eta motor is 'low friction' is the >>valvetrain. The eta cam only has 4 bearings, as opposed to the >>7 on other small-6 motors, and the valve springs are considerably >>softer too.

The Metric Mechanican (MM) Catalog (816)231-0604 agrees with Ben's statements. The ETA engine has four bearings versus seven on the 325i head. However, the ETA engine still has the same basic head with seven bearing journals. MM uses the 325i (seven bearing) camshaft with stiffer valve springs, by drilling extra oiling holes in the three other cam journals. The head is ported for a 19% flow increase.

MM uses 85mm (versus stock 84 mm) pistons with very deep valve reliefs, so a broken timing belt won't cause bent valves (valves can't hit the pistons). Stock rods and crankshaft are used. Redline is increased from 4,800 to 6,000 rpm. Horsepower increases from 121 stock to 185.

Warning; I'm just reading this out of the MM catalog, so I really don't "know" any of this for sure. But even with the new 6,000 rpm redline, the ETA engine (81mm, 3.19 in stroke) still has a very conservative mean piston speed of 3,196 ft/min versus the positively slow 2,557 ft/min at the stock 4,800 redline.


From: john hartge <jhartge_at_dgs.dgsys.com> Date: Tue, 14 May 1996 09:16:20 -0700

you can install "i" cam and springs into an "e" head, but... you must drill additional oiling holes in the cam bearing journals not used by the "e" cam but needed for the "i" cam. you must change the computer chip to provide for new cam profile and higher revs to about 6,000 rpms. to really enjoy additional horsepower, get a new gear ratio for the rear, say 3.45 or 3.73. it's a nice torquey setup. you've got to have a strong bottom end, also. as old as these cars are getting, with high mileage, you might just find or make a 2.5 or 2.7 "i" engine.


15.9.4: Racing Harness Install
From: marshall.garrison_at_cccbbs.cincinnati.oh.us (MARSHALL GARRISON) Date: Thu, 23 Feb 95 14:26:00 -0500

OO> I want to install a set of four point harness racing seat belts in OO> my 1988 E30 M3. I want to use snaps and eyebolts so that I can OO> remove the harness when I'm not at the track and use the OEM belts OO> for the street.

Installed a similar setup in my '87 325is last year. Racer Wholesale in Georgia provided belts and hardware; most importantly, metric eye bolts, both short and long. For an E-30, replace the front floor bolt of the lower seatbelt bracket with an eyebolt. Check clearances underneath before installing, brake lines I think run directly under the bolt hole, so a shorter bolt may be better for one side or the other. You will probably have to use washers so the bolt will tighten down in the proper orientation (you want the lap belt to come up flat over your waist).

You'll have to remove the seats to install the inboard bolts for both seats. The metric eyebolts will replace the 17mm bolts at the seat's pivot points inboard (transmission tunnel-side) or the seatbelt mounting bolts - sorry, forgot exactly which since last summer. The 17mm bolts are covered by plastic caps which pop off easily. Clearances are very close, the eybolts will rub against the carpeting slightly, but they will fit. The tricky part is getting the eyebolts oriented correctly so you can snap the lap belt in and out, because the eyebolts pivot w/ the seats as you change seat position. So, you want to make sure the seat is in the rake/height position you'll have it in for the track. On stock BMW sport seats, I found it far easier to snap in the inboard lap belts and leave them in place, as there is so little clearance that it is difficult to snap them in and out. Adding tabs to the snap-clips themselves might make that easier, which is something I thought about but haven't done. I just swivel the inboard lap belts out of the way, and remove the shoulder harnesses and outboard lap belts to use the stock belts.

Thus far the modifications are easily reversible, and allow for a completely solid mounting for the lap belts. For a crotch belt, bars were welded between the lower seat rails w/ bolts welded on, to which the crotch belts attach and are bolted to. I slit the leather in the thigh extension flap to thread the crotch belts through. I know of other installations where they're simply bolted through the floor. Always check the underside first, you don't want to inadvertently drill through anything important. BTW, For the sill-side eyebolt, I had first tried the seatbelt lower bar's REAR (b-pillar) mounting point for the eybolt; don't do it, it doesn't place the lap belt in the proper position to be tightened down adequately.

Being tall, I didn't want to run the shoulder belts downwards behind the seat to the rear seatbelt mounting bolts, which is a typical choice. I chose instead to run eybolts through the rear deck (inboard of each rear speaker, with enough room for the snap-clips to attach/detach), through custom cut reinforcing plates in the trunk, against the rear deck panel. The carpeted rear deck panel was cut out w/ holes just large enough so the eyebolts could have metal-to-metal contact; ie: Eyebolt, large 1/4" thick washer, metal rear deck panel, reinforcing plate, lockwasher, and nut. Obviously the eyebolts stick up through the carpeted rear panel, but it looks okay, at least as a compromise for me.

Underneath the carpeted rear deck panel is some kind of welded bracket w/ a bolt hole, maybe two on each side - it may be possible to use these as a mounting point, but I chose not to trust the strength of the BMW tack weld, vs. a plate and the rear deck, etc. FWIW, I had first tried a Schroth 2" 4-point harness w/ (get this) steel carabiners since they didn't have snap-clips; I found that I couldn't get the lap belt tightened securely enough, as tightening the shoulder belts would always pull up the lap belt. The Schroth was difficult to pull tight also. I settled on a "Y" shoulder harness w/ snap-clip, pull-up lap-belts w/ snap-clips, and a bolt-in crotch belt (3" TRW Sabelt cam-lock setup). This is somewhat easier to adjust and tighten than the Schroth, but far more secure - I am really locked into the seat when everything's tightened down. Hope that helps, e-mail if you have any questions -

marshall.garrison_at_cccbbs.cincinnati.oh.us

  • RM 1.3 02862 * RoboMail -- The next generation QWK compatible reader!

(by Rick Kjelsen fcmk_at_watson.ibm.com)

An alternative to the above shoulder belt technique is to run the belts down to the rear seat seat belt bolt holes (replace bolts with harness eye-bolts). You can run them directly to your shoulders from there, but for a safer installation you want them pulling straight back, not down. Several places sell a bar that bolts between the stock front shoulder belt mounting bolt holes that is designed for a harness. You can attach the harness directly to it, or to the rear belt mounts and run them over the bar. The bar bolts in/out in a few minutes, or you can leave it in full time, and the stock belts will work fine with it in place - getting into the rear seat is tougher though.


15.9.5: Sway Bar mount points
(by Rick Kjeldsen fcmk_at_watson.ibm.com)

(When installing big sway bars...)
>I've heard that not stregthening the mounting points for the bars will >eventually cause them to rip away.

No question about it. The worst problem is with the inner mounts up front. Stock, the bars attach to a flimsy tab off the back of the subframe. But because that is a known problem, most front bars come with a stronger mount that uses one of the subframe bolts as well as the tab. That seems to completely solve the front problem.

Soon after installing big rear bars almost everyone breaks the little triangle on the trailing arm that the bar end-link bolts to. Many bars come with triangular metal parts that are intended to be bolted on either side of the tab like washers. They help a little, but not much. The best solution is to have a welder re-enforce that tab with buttresses back to the trailing arm itself, as well as thicken the tab with an extra layer of steel welded on. You have to be careful because the brake line passes right under the tab. Overall it's an easy job because access is so easy (no need to pull the arm off).
The heat of welding will destroy the undercoating around the tab both inside and outside the trailing arm, so if you care about that kind of thing, be sure to re-undercoat outside, and spray some body-cavity sealer into the arm (the access hole is on the outside end where the wheel mounts, covered by a small plastic cap).

A second problem in the rear is that the inner sway bar mounts (to the car body) will flex, fatigue and eventually fail. This is less common. It seems to happen faster with setups having softer springs and stiff bars (street/track setups, rather than track-only setups), but I've seen evidence of it starting on nearly every tweeked E30s I've looked at that is run on the track. I was hearing a loud popping when turning over road elevation changes for several months as the cracked mount would "oil-can" and the sound would echo through the car. Eventually it failed on a steep driveway and the bar ripped off completely. ("So THAT is what that noise was!!")
Unfortunatly it failed just a week before a track event!

To fix it you will need to pull out the sway bar and on the passenger side pull off gas tank filler pipe. (CAREFUL welding with that gas tank open under there!) You can comfortable work around the axles, diff, etc down there. It takes a little fabrication to build steel tabs to strengthen the mount. I found it best to just double up the existing mount with 1/8" steel on the "inside" (front) in such a way that left the bar bracket mounting area untouched. That let me use the old sway-bar brackets, and we didn't have to fabricate new ones. This will be tough to re-undercoat well because of all the corners and stuff, but if it's a street car be sure to do it, as it WILL rust (because of all the corners and stuff).

There is another alternative for the rear body mounts. Some tuners sell a re-enforced mounting bracket that bolts through the trunk floor as well as to the sway bar bracket. Costs over $200 from Korman. You have to add it BEFORE you fatigue the mounting point, it's not an after-the-fact fix. No experience with it.

rick
'87 325es with all new sway bar mounts

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