12.2.1 E23 center console
12.2.2 E32 Power Seats
12.3: Engine & Transmission
12.3.1 '88 735i hard starts
12.3.2 Temperature sensor and oil drip
12.3.3 [735i] Transmission Faliures
12.4: Suspension & Steering
12.4.1 Steering Wheel Shimmy
12.4.2 Power Steering booster
12.4.3 E28 ZF steering box (same principal as E23/E32)
12.4.4 Power Steering Pumps
12.4.5 Re: 7er struts DIY
12.5: Brakes
12.5.1 Proper brake bleeding proceedure (745i)
12.5.2 Brake Noise, 735i
12.5.3 Brake Pressure Warning Message
12.6: HVAC
12.6.1 Fan Control
12.6.2 1989 E32 Microfilter, Glovebox, HVAC Fan
12.6.3 <850i> squeaks from HVAC
12.6.4 Water control solenoid 7er heat
12.7: Electrical
12.7.1 Firmware Upgrades?
12.7.2 Replacing OBC Light Bulb
12.7.3 735il EML failure
12.7.4 Tachometer not working
12.7.5 Mirror Tilt
12.7.6 Retrieving Motronic Codes From Your Car
12.7.7 climate control lights
12.8: Misc
12.8.1 Official BMW Cruise Diagnosis (long and taken from E28, but the
same)
12.8.2 535 Fuel Delivery Problems? (same for 3.5l 7er)
12.8.3 Checklist
12.9: Performance
12.1: Overview
12.2: Body
12.2.1 E23 center consloe
From: "jlcl01::mrgate::a1::pappentl"_at_jlcl01.dnet.dupont.com
Date: Sat, 22 Jun 96 19:57:14 EDT
Subject: E23 center consloe
Help! I need to remove the center console on my 1984 735i so I
can repair a leak in one of the air vent vacuum lines. I can get
the cover off the parking brake, but I am clueless as to the
center console. There is a screw on the casette holder, and a
10mm nut that was hidden by the brake cover, but what else is
holding this console on?
...Tom
pappentl_at_udel.ed
From: Looi Cheng Hock <lchock_at_pop.jaring.my>
Date: Sun, 23 Jun 1996 10:27:23 MYT
Subject: Re: E23 center consloe
On Sat, 22 Jun 96, "jlcl01::mrgate::a1::pappentl"_at_jlcl01.dnet.dupont.com
wrote:
>Help! I need to remove the center console on my 1984 735i so I
(snipped)...
>center console. There is a screw on the casette holder, and a
>10mm nut that was hidden by the brake cover, but what else is
>holding this console on?
You're almost there. Apart from the frontal 10mm nut, you'll have
to remove another 2 screws - reach from the rear air-vents.
Just pull off the air-vents control slider. Undo 2 screws that hold
the air-vents shroud. Pull off the cig. lighter wire - make sure they
don't *short* to bare metal. With the air-vents shroud removed,
you'll see another 2 screws that hold the rear end of the whole
lower center console over the hand-brake unit.
For complete removal, you'll then have to disconnect/unplug all
the power-window switches. That's about it.
Cheers!
>...Tom
>pappentl_at_udel.edu
-- chL00I
via DeskTopPC
West Malaysia.
84 E23 728i
71 Opel Manta SR
12.2.2 E32 Power Seats
From: dld_at_symtec.com (Doug Donsbach)
Subject: Re: E32 Power Seats
Philip Patrick asked about working on power seats.
Go for it Phillip. These things are easy to work on and really very simple.
If you have to get under the seat, remove the pins at the front of the seat
and just let if flop back.
I've hacked just about everything on mine, including removing and repairing
the seat control switches (only for the truly demented).
Yell if you have questions and I'll help where I can.
Good Luck,
Doug
From: Philip Patrick <philip_at_america.net>
Subject: Thanks Steve (E32 Seats)
Today I took your advice and pulled the head rest motors to check the =
cables. On the driver side seat, I put a 1/2 inch piece of coat hanger =
down in the motor shaft. It worked great. On the passenger side I had =
to pull the cable out and cut the sheath at the edge of the metal ring =
that inserts in the motor. Then I had to pry the small piece of sheath =
out of the ring. There are a couple of cutouts in the ring so it holds =
the sheath in the ring. I had to bend these out and put the old sheath =
back in. I put it back together and it works great. All of this took =
no longer than about 20 minutes. Tomorrow I am going to work on the =
passenger seat and try to get it to work right. It works except you =
have to help it recline. I will let everyone know how this works out, =
when completed.
Thanks for the good advice.
Philip
88 735i 5 speed
87 300D
12.3: Engine
12.3.1 '88 735i hard starts
From: "Craig Lovold" <clovold_at_mail.mecc.com>
Subject: '88 735i hard starts
'88 735i hard starts
My wifes car has a very frustrating (and embarrassing) problem. It must be
fairly warm out (75 degrees or better, high humidity makes it worse).
When the car is driven enough to fully warm it up and then let stand for
about
an hour (like at her aerobics) it is very hard to start. Turn the key, it
starts to catch and then kills. It does this about 7-10 times before it
will
finally keep running. This will only happen if the car has been sitting for
45-70 minutes, outside that range it starts fine.
My wife is fed up with it. Could it be vapor lock? what is vapor lock? Why
do
you have to let it sit 45 minutes before you have a problem?
TIA for your help.
Craig Lovold
From: Doug Donsbach <dld_at_symtec.com>
Subject: Re: '88 735i hard starts
Craig Lovold wrote about hard starts when the 735 is hot/warm.
I'd check in order the idle stabilizer and the coolant temperature
sensor. Pull the stabilizer (from the passenger side, to the left
of the air flow sensor) and spray it with carb cleaner or brake cleaner.
The specs for the resistance of the temperature sensor are in the
Haynes 3/5 Series Book.
Good luck,
Doug
12.3.2 Subject: Temperature sensor and oil drip
From: Reuben V Regucera
Subject: Temperature sensor and oil drip
From: "KEVIN MOAK" <kmoak_at_va.gibbscox.com>
On another topic, I noticed FRESH oil around the tip of the timing
chain tensioner anti-tampering cover this weekend. Wiped it off, and
it was back the next day. Very slight leak, but is it possible that
it is coming from another source besides the tensioner? I can't
really get a good look at that area without taking a LOT of stuff off
of the car. There's an oil spot b
below this area on one of the
underside mud/stone guards, so it's been leaking for awhile, but I'm
not down on oil in the crankcase, so it is a very minor slow leak.
Still, it IS a leak, and since this isn't a British sports car, I
don't expect ANY sort of a leak. Any thoughts or ideas?
Kevin,
There is an o-ring inside the belt tensioner that hardens over time.
I replaced the o-ring in my 750 and the leak went away. To replace
it you need to buy, the o-ring, crush washer, and the anti-tampering
plastic cover. The only hard part is putting bolt back because of the
spring. You have to have a strong arm to push back the spring while
turning the bolt to bite into the thread.
If you need more info, just drop me an mail.
Reuben
reubenr_at_netcom.com
89 750iL
> From: "KEVIN MOAK" <kmoak_at_va.gibbscox.com>
> Subject: Temperature sensor and oil drip
>
> Question #1 - Where under the hood is the sensor mounted?
I haven't tracked it down recently on the 750 (did about 2 years ago) but
my other BMWs have it clipped near the center Kidneys - either directly
or on the top of the bumper.
C. Koch
> not down on oil in the crankcase, so it is a very minor slow leak.
> Still, it IS a leak, and since this isn't a British sports car, I
> don't expect ANY sort of a leak. Any thoughts or ideas?
>
Every BMW I've owned leaks (although as you said, not nearly as bad as
English cars). Usually temp or pressure sensors. But most often the
(damn) hydraulics. Those rinky dink aluminum rings are lousy! I've
replaced so many trying to stop drips - and almost always without
success. By the way, the fluid may end up anywhere: check it out.
I have found that most ordinary engine seals on BMWs are much better than
average - most can be reused over and over unless abused by overtorquing.
Christopher Koch wrote:
>
> The local chapter (Boca Raton, Florida) steered me to their favorite
> local shop who had an ex-Dealer technician who told me "we replace these
> like popcorn" and "they failed often during something as simple as the
> walnut-shell valve cleaning procedure" and "don't run the car in park or
> neutral more than a minute or two - the transmission will overheat" and
> "ZF made several revisions - be sure you buy the latest".
>
There was something in the technical notes or letters of Roundel mid-year
in 1994 about this. There apparently is a problem associated with running
the transmission at elevated RPM in neutral which will cause nearly
immediate failure of the transmission. This apprently was happening during
the emission tests required in some states. The text there went on to
describe a procedure (can't remember if it was a BMW procedure or what) to
keep from destroying the transmission. It had to do with limiting the
amount of time the engine was kept at elevated RPM in neutral.
The more I think about it the more I seem to remember that the problem
involved all 7's, not just 735's.
Doug Donsbach - dld_at_symtec.com - Knoxville, TN
'88 735i BMW CCA - '88 951 PCA
I ran out of time giving my ZF feedback above. Yes, can you imagine such
advice as "limiting the amount of time to less than 60 seconds"? How
absurd! As if transmissions were new devices and hadn't been popular
since the fifties. But, take heed, and don't violate this limit.
Since my 1987 735i ZF HP22 failed, I have asked every BMW mechanic I've
encountered (Oktoberfest, Concours, Meetings, etc.) about the mighty ZF
used in our sevens (until replaced by the current ZF five-speed). They
all have readily admitted the (very) high failure rate.
I wrote a letter to BMW NA about this and they replied that there was no
significant failure rate on the ZF transmission. Either they are in
acute denial or most BMW owners are sharp enough not to pay $3500 or more
at the Dealer - prefering the little local tranny shop...
The second thing I did after purchasing my 750iL was acquiring a ZF HP24
tranny out of a wreaked 1992 750iL (by the way, the engine was
transplanted into a 635CSi!). It now occupies my engine stand, ready for
the day it needs to be pressed into service. I also immediately drained
(repeatedly) and ran twelve quarts of Amsoil synthetic through the
original ZF. I still keep a close eye on the fluid, but all has been
well so far...
Christopher Koch
From: "Christopher P. Koch" <bt294_at_FreeNet.Buffalo.EDU>
Subject: RE: e32 tranny
On Mon, 25 Mar 1996 bmw-750_at_transarc.com wrote:
> From: powdah_at_mainelink.net (David Leonard)
> Subject: e32 tranny
>
> It seems to me that whether or not the car is in gear has little to do
with
> fluid heating, because as I see it the torque converter spins either way,
> and this is the primary source of fluid heat. True, the tranny in neutral
> should heat less, as the gears are freewheeling rather than doing work,
but
> never the less there is no cooling airflow.
>
> I don't know if the cars have an external oil cooler, or just use the pass
> through the radiator. Anybody know? Seems like it may be worth adding
one.
>
> Dave Leonard
> 88 e32 735ia
> 107k
Dear Dave,
I doubt very much if "air cooling", that is, the flow of air past the
transmission at speed has any basis in reality. First, the transmission
has little if any cooling "fin" to increase surface area. I just looked
at my spare in the basement and all "fins" are structural (increase
rigidity of case). Plus the tranny is downstream of an engine that is
belching heat.
Our BMWs have a heat exchanger built into the radiator - just like
American cars. Therefore, this warms up a cold tranny and (somewhat)
cools a hot one.
I further doubt if the prior history of any BMW has any effect on
transmission life. Most BMWs are serviced at the Dealer for the first
70K miles by the (wealthy) first owner and Dealers usually change the trans
oil every 30K (some of you may argue this - but most every BMW I've
considered to purchase had these
services on the service invoices).
The ZF was poorly designed - that is all one can conclude. I have NEVER
had a problem with any automatic transmissioned vehicle before (I'm on
#48)! I NEVER had to turn off an idling engine running the A/C before my
BMWs! I NEVER
had to watch elevated rpms over time when servicing my cars!
Yours, Chris Koch
>
From: powdah_at_mainelink.net (David Leonard)
Subject: Still more tranny madness.
Found this on the digest.
I think its relevant:
Well, Im not sure about the bulletin on the ZF trans, but I do know
the problem...Its after the car is put in a drive gear,then into neutral or
park, that if you rev the engine, it will burn out the trans. The cause is
that this particular trans keeps fluid pressure on, even though youve
shifted
to neutral. This causes the front A clutch pack to basically wear itself
out,
very fast, since the clutches will be taking all of the engine power and no
transfer to gears. My friend at work fixed on of these ZFs by replacing the
front A clutch pack. The trans was saveable.
BTW this also pertains to Volvos, Jaguars and other cars that have
this ZF trans. Ive seen many BMWs at work come in with only reverse gear,
and
no forward because of a burnt out trans.
The only way to rev your engine after putting it into gear fairly
safely is to stop the engine for 30 to 60 seconds, then restart, put dont
put
into gear. The ZF in my 87 Volvo is still good and shifts nice a crisp, if a
bit firm. Hope this helps.
BTW, I work at BMW of Honolulu, but my comments and suggestions are
from my experience and not those of BMW NA or BMW of Honolulu.
Mahalo Alan Chung 91 525iA Dinan Chipped
From: Brian Mihalka <brianm_at_ix15.ix.netcom.com>
Subject: Re: Still More Tranny Madness
David found this on the digest:
>>>Well, Im not sure about the bulletin on the ZF trans, but I do know
the problem...Its after the car is put in a drive gear,then into neutral or
park, that if you rev the engine, it will burn out the trans. The cause is
that this particular trans keeps fluid pressure on, even though youve
shifted
to neutral. This causes the front A clutch pack to basically wear itself
out,
very fast, since the clutches will be taking all of the engine power and no
transfer to gears. My friend at work fixed on of these ZFs by replacing the
front A clutch pack. The trans was saveable.....
The only way to rev your engine after putting it into gear fairly
safely is to stop the engine for 30 to 60 seconds, then restart, put dont
put
into gear. The ZF in my 87 Volvo is still good and shifts nice a crisp, if a
bit firm. Hope this helps.<<<
Thanks a lot David for fowarding this to our list; I really appreciate it.
It confirms what my mechanic has told me about high pressure in neutral/park
ruining the transmission.
The way I interpret all of this is that the "solution" that described above
assumes that the clutch plates are not pressurized by the pump while the
trans is in neutral or park. Consequently, the clutch failure occurs not
because the pump is still directly pressurizing the plates in neutral/park
but because the pressurization that occurred while the trans was in a drive
gear was not bled off when neutral/park was subsequently selected.
This would lead one to conclude that even letting the engine idle at 800 rpm
in park or neutral after running a drive gear would cause premature wear of
the clutch plates which are still pressurized at the same pressure that
existed when the trans was in gear.
Anyone have comments on this to the contrary? Although some might say we're
beating this topic to death, I think we're finally understanding the exact
circumstance causing transmission failure during high idle smog checks. I
feel better. Do you feel better?
Brian
1991 750iL (in the shop, again)
From: Jeff Moser <jrmoser_at_nando.net>
Subject: 735 Automatic Transmission Saga... Part III
Well, where this last left off, the dealer where I had my car inspected, had
admitted wrong doing.
The next time I spoke with them, they had a completely different attitude
about their wrong doing. They sent me a copy of a transmission service
bulletin (I don't have the number, but I will post more about it at a later
date if desired). The service bulletin describes proper emissions testing
procedures for 1985-1987 BMW's with the 4-speed automatic transmission.
The basic gist of the bulletin, is that it is permissible to operate the
engine at speeds up to 2000 RPM for up to 90 seconds with the transmission
in park (not neutral) ONLY if the engine has not been running for at least
30 seconds, and ONLY if the transmission has not been shifted into any gear
other than park.
Once the transmission is shifted into any gear (forward or reverse) the
clutches are pressurized, and stay pressurized until the engine is turned
off for at least 30 seconds.
PLEASE NOTE: This particular transmission problem does not only happen
during emissions inspection. It can happen during AC recharging, engine
diagnosis, etc. It can happen any time that the engine must be operated at
elevated RPM for more than 90 seconds!
My situation now is that the dealer is offering to redo the state inspection
with me watching, but they do claim that they tested the car correctly the
first time, and hence caused no damage to my transmission. I see no
justifiable reason to do this, as it can only cause more wear and tear on my
car.
Since I have received the bulletin, I at least feel better about the
situation. I am trying to get the dealer to try and find a bulletin that is
specifically about 1989 model cars.
(Prakash: Does your Alldata CD have any bulletins/procedures for emissions
testing of automatic transmission cars?)
My question for you folks is: Does anyone have any official written
information that would contradict what the dealer has told me?
Thanks for all of your help and support.
Jeff Moser
From: powdah_at_mainelink.net (David Leonard)
Subject: Transmissions in transition.
Brian wrote;
"This would lead one to conclude that even letting the engine idle at 800
rpm
in park or neutral after running a drive gear would cause premature wear of
the clutch plates which are still pressurized at the same pressure that
existed when the trans was in gear."
I am not sure this is the case, because even if the clutches are pumped up,
the torque converter slips mightily at 800 rpms, where when it is revved, it
approaches its stall speed, and then becomes much more of a solid coupling
between the engine and transmission. This would certainly dump a lot more
power into the clutch packs than when idling at 800. At Idle the heat
buildup is being dumped into the transmission fluid, and cooled. When
revved, the power is going int the clutches, and the heat is staying there ,
and rather than being dumped harmlessly, it is burning the friction material
of the bands.
I have no real knowlege of what the stall speed of the e32 converter is, but
I know for small block Chevys you buy hi performance converters w/ a 2500
rpm stall speed for hi-po applications.
My understanding is that the stall speed is the theoretical speed that the
engine would stall at WOT, if the output shaft were held stationary. I
could be all wet with this theory however, you never know! If anyone can
enlighten me on this, please do so.
Dave Leonard
From: Brian Mihalka <brianm_at_ix12.ix.netcom.com>
Subject: Epic Re:735 Automatic Transmission Saga ... Part III
To everyone: excuse the bandwidth but I wanted a big finish to the
continuing saga of the flawed BMW transmission (call it the Cecil de Mille
syndrome).
Jeff Moser <jrmoser_at_nando.net> wrote:
>>>The service bulletin describes proper emissions testing
procedures for 1985-1987 BMW's with the 4-speed automatic transmission.
The basic gist of the bulletin, is that it is permissible to operate the
engine at speeds up to 2000 RPM for up to 90 seconds with the transmission
in park (not neutral) ONLY if the engine has not been running for at least
30 seconds, and ONLY if the transmission has not been shifted into any gear
other than park.
Once the transmission is shifted into any gear (forward or reverse) the
clutches are pressurized, and stay pressurized until the engine is turned
off for at least 30 seconds......
My situation now is that the dealer is offering to redo the state inspection
with me watching, but they do claim that they tested the car correctly the
first time, and hence caused no damage to my transmission. I see no
justifiable reason to do this, as it can only cause more wear and tear on my
car. >>>
>From BrianM (BrianM_at_ix.netcom.com)
Jeff,
I checked my AllData info and could find no service bulletins regarding this
issue. My disk only covers 1991 BMW's so this doesn't necessarily mean that
a relavant bulletin does not exist.
I did contact the BMW mechanic, Alan Chung, in Hawaii who had posted an
entry in the digest pertaining to this transmission issue (I think it was
Dave who originally posted a copy of this to our list).
>>>>{Part of whate Alan originally wrote in the digest:
> The only way to rev your engine (in neutral) after putting it into gear
> fairly safely is to stop the engine for 30 to 60 seconds, then restart,
but
> don't put into gear.<<<
I replied to him:
> The way I interpret all of this is that your solution assumes that the
> clutch plates are not pressurized by the pump while the trans is in
neutral
> or park. Consequently, without your solution, clutch failure occurs not
> because the pump is still directly pressurizing the plates in neutral/park
> but because the pressurization that occurred while the trans was in a
drive
> gear was not bled off when neutral/park was subsequently selected.
>
> This would lead me to conclude that even letting the engine idle at 800
rpm
> in park or neutral after running a drive gear would cause premature wear
of
> the clutch plates which are still pressurized at the same pressure that
> existed when the trans was in gear.
Alan replied to my inquiry:
>>>Let me follow up as best I can...Yes the trans will be pressurized
>after putting it into a gear. If neutral is then selected, the pressure
does >not bleed off sufficiently. Your explanation is very good. Revving the
engine >makes it worse because it puts more load on the clutches.
> The 750s have the ZF 4HP24, which is a heavy dutier version of the
>hp22. However, its design is the same and it is afflicted with the burnout
>problem. I have seen 750s come in the shop with this problem, although
mostly
>88-89's with high mileage. You can eventually burn out the trans while
idling
>at normal idle as well too.
> I was in this 750 that was in for trans repair and I started it up
when >it was cold, put it in drive and it worked. Then, I let it idle for
awhile and >went back and put it in drive and no go. So I turned the engine
off, then >restarted it and drive worked again. So idling for prolonged
periods can burn >the trans as well.
> I think that this problem made the ZF a poor transmission. Other than
>that it is pretty strong and all.
> Well, I hope this helps, let me know if you have anymore questions.
>Mahalo Alan Chung 91 525iA Honolulu, HI >>>
Jeff,
I agree with you - redoing the emissions test will serve no purpose. As I
mentioned before, however, you need to drop the transmission pan to check
for debris. If the clutches were overheated you should find a lot of clutch
material in the bottom of the pan. If the pan is clean (and the dealer
didn't have a chance to clean it before you looked at it) I wouldn't worry
about it.
In conclusion, we have it from two sources (your dealer and Alan) that we
must stop the car, wait for at least 30 seconds, and then restart the car
before running at 2000 to 3000 rpm in neutral or park. Engaging a drive gear
at any time requires that the process be repeated due to hydralic pressure
not bleeding off when the trans goes from a drive gear to neutral/park.
After all of this I think we can safely assume that we have gotten a handle
on what is actually going wrong inside the transmission when emission
testing (and other procedures like A/C charging) is done. By knowing exactly
what is going wrong we now know how to avoid placing the transmission in
jeopardy.
Also, based on the service bulletin you mentioned the problem seems to be
restricted to pre 1990 transmissions although I'm going to treat my '91 as
if it also has this failing. Despite assurances to the contrary, I also plan
to play it safe during my car's next emissions test and put the rear wheels
in the air and leave the transmission in drive. Afterall, it doesn't really
cost anything to be too careful.
Jeff, could you please give me the number of the service bulletin in
question when you get the chance. Thanks!
Brian
1991 750iL
From: Jeff Moser <jrmoser_at_nando.net>
Subject: Transmission Saga...Final Chapter
Well, as the subject says, this is the final chapter to the automatic
transmission story. I am finally convinced that no damage was done to my
transmission during the emissions tests. Since it is time to change the ATF
anyway, I will check out the inside of the oil pan soon, just to be
absolutely absolutely positively convinced.
As I said before, the dealer provided me with a copy of service bulletin #
24 01 91 (3196) dated June 1991. BMW NA called me today, and comfirmed what
the dealer had told me. Since the dealer freely gave me a copy of the
bulletin, I am going to post it here as follows. Thanks for everybodys help
and suggestions. NOW: Lets get on with some new and different topics!
Subject: Transmisison Failure during Exhaust Emission Testing
Models: All 1984, 1985, 1986 with 4-speed automatic transmission, 1987
635CSi, 735i, and L7.
Situation: There have been reported isolated cases of automatic
transmissions failing during a High Idle Exhaust Emissions Check. The
failures have resulted from a preconditioning procedure where the engine is
held at high rpm for a prolonged period of time. The following applies to
all states which have a High Idle Exhaust Emission Check.
As the internal transmission components experience normal wear over time,
the possibility of transmission damage exists if the vehicle is operated for
extended periods of time at high rpm in PARK or Neutral. Such operation
does not constitute normal operating conditions. If, in exceptional cases
such as A/C recharging, injector cleaning, charging system tests, or
emissions testing, vehicle operation at high rpm in PARK or Neutral is
required the following setup procedure must be performed prior to beginning
such operations.
Solution: The emissions test must be conducted with the engine at operating
temperature. If the engine is not at operating temperature prior to
beginning the test, it is recommended that the vehicle be driven for a short
period of time to bring the engine to operating temperature. DO NOT run the
vehicle at high idle to achieve operating temperature.
Once the engine has reached operating temperature, the following pretest
procedure must be performed BEFORE testing begins.
Setup Procedure for I/M Emission Test
Shift to PARK.
Turn engine OFF.
Wait at least 30 seconds.
Restart engine, LEAVE TRANSMISSION IN PARK.
After the engine is started, DO NOT move the gear shift selector through the
Forward or Reverse gears before or during the test sequence. DO NOT EXCEED
2000 RPM.
Begin emissions test procedure.
If the vehicle fails the emission test, some states allow for an
extended pre-conditioning before the repeat test. In this case the
following procedure should be adhered to.
Precondition Procedure
Shift into PARK and turn the engine OFF for 30 seconds.
Restart engine, LEAVE TRANSMISSION IN PARK.
Engine may be preconditioned at a maximum of 2000 RPM for up to 90
seconds, at which time the repeat test must begin.
If the above steps are not followed, serious transmission damage can result.
Note: Due to the unusual nature of the emissions check, this type of
failure does not take place under normal operating conditions.
Hi Folks, (Can you tell that I am from the South?)
I finally got around to changing the ATF in my car over the weekend. I
drained out the old fluid which was a pinkish-brown color and smelled
slightly burned. I then proceeded to remove the oil pan to take a look
inside. I was kind of nervous, due to the recent emissions test fiasco that
the dealer put my car through. When I looked into the oil pan, I was
delighted to see no debris in the pan whatsover. Not metal particles, not
clutch particles, nothing, nada, zip! The outside of the filter was coated
with a fine layer of clutch particles and the filter screen was not clogged.
Anyway, I put on the new filter and pan gasket and buttoned it back up. I
filled it with Mobil 1 synthetic ATF. I went for a test drive, and I
noticed a definite improvement in the operation of the transmission.
Although I was not experiencing any operational problems with the
transmission before, the new fluid made the transmission seem to operate
much better. I don't know exactly how to describe the differences, but the
transmission now feels more "solid" and "smooth". The car seems to
accelerate from a standstill much more stongly than it did before, even
though it worked perfectly fine before.
One other definite improvement that I noticed is that the annoying driveline
shudder that had been occuring in my car, ever since I have owned it, in
the speed range of 0-20 MPH is now GONE! I was expecting to have to replace
the drive shaft to cure this problem.
Now I don't know exactly how to attribute the differences in operation. Did
the synthetic ATF cause the improvement, or did just changing the fluid in
general cause the improvement? After thinking about it, I tend to believe
that the synthetic ATF caused the difference because the car has had the
driveline shudder for quite a while, even when the original transmission
fluid was clean(er). Anyway, since I am still running at least a half and
half mixture of synthetic/dirty fluid, I am going to drain the fluid again
in a week or so, and put in some more Mobil 1 to improve the synthetic/dirty
fluid ratio.
I know that this is getting long, but while on this subject, I recently
purchased an ATSG ZF 4HP22 rebuild manual from the Transmission Exchange
(1-800-776-1191) for $12.00. Of course, the book describes how to rebuild
the beast, but more importantly, it describes some modifications that must
be made to these transmissions to correct "Premature Forward Clutch
Failure".
The problem is that the seals or the bore of the main input shaft can wear,
and cause fluid to leak from the torque converter directly into the forward
clutch (clutch A), causing the clutch to activate. Clutch activation in
these circumstances can cause the clutch to fry and/or the car to try to
move forward when in neutral if the engine is accelerated above idle. To
correct the problem, one of the shaft seals must be changed from steel to
teflon, a 0.045" diameter hole must be drilled into the forward clutch A
piston (to bleed off any misapplied pressure), and the forward clutch
orifice in the valve body must be enlarged (to compensate for the lost
pressure due to the 0.045" hole in the piston). The manual doesn't say what
years of transmissions are affected by this problem. I remember someone
from this digest describing a similiar procedure that was done when their
transmission was rebuilt (Chris?). I also know that BMW had a transmission
recall in the 1986 timeframe for a similiar problem.
Also, one last bit of trivia: Did anyone know that the ZF 4HP22
transmission was used in 1985 Lincoln Diesels?
My 1989 735i has the famous steering wheel shimmy when braking in the 60-45
MPH speed range. The car has had this shimmy ever since I have owned it.
Right after I bought the car, I thought that the problem was warped brake
rotors, so I had the front rotors turned (I know, I know). The problem went
away for a while, so I am pretty sure that the problem is really the brake
rotors, and I am thinking about replacing them.
I also thought that maybe the less than perfect tires that were on the car
were also part of the problem. I finally had new tires put on the car and
the problem is still there.
I just wanted to run this past you experts and see what your opinion is. I
am planning on ordering a couple of brake rotors, and a new set of pads in
hopes of curing this problem.
Is there anything else that I should be checking? Any good (and
inexpensive) sources for rotors and pads?
BTW: The car has new Thrust bushings, and I have a new right side upper
control arm that I am going to have installed also.
12.4.2 Power Steering booster
From: Peter Ta <pta_at_Mitchell.Com>
Subject: Power Steering booster?
Hi,
Does anyone know this device under my 750, -cylindrical shape attached to
the power steering reservoir, called and how much it cost to replace it. It
leaks power steering fluid. Thanks in advance. Peter
Peter;
I had this replaced, my mechanic called it an accumulator, it boosts the
power steering
and the brakes. I was charged $561.00 and after 2 days the reservoir
overflowed
all over my garage floor, my BMW dealer would have charged me the same and
they would have tried to resolve the problem, my mechanic said this was just
a
coincidence and to monitor the situation? If anyone cares I just had an
evaporator
and drier and a hose replaced for only $2,250.00, oh the wonders of owning
one of these beautiful automobiles.
Jack
computerconsultants, inc.
cocoinc_at_shadow.net FAX (954)927-5838 VOICE (954)927-1412
12.4.3 E28 ZF steering box (same for 7er)
From: Don Eilenberger <deilenberger_at_monmouth.com>
Date: Tue, 25 Jun 1996 19:30:53 -0400
Subject: RE: E28 ZF steering box
Richard asks:
>Subject: E28 ZF Power steering box overhaul?
>
>I have a 1986 525iSE which has a certain amount of slop on the powersteer=
>ing box input shaft. When the steering is turned a quarter of the way fro=
>m the centre position, it can be rocked 1" left and right without moving =
>the roadwheels.
>
>I carried out the usual preload adjustment by slackening the 17mm locknut=
> on the top of the steering box and turning the screw in the centre of th=
>e nut in 1/4 of a turn. This got rid of the play, but leaves a dead/heavy=
> feeling in the centre area of the steering plane.
This is BAD - it means you've overadjusted - and will destroy the
bearings in the steering box.. loosen tonight! The real procedure
for setting the bearing preload in the box involves removing it
from the car and using a precision torque indicator on the
input shaft while adjusting it. There is also (at least on mine)
a secondary adjustment for the input shaft end-play which is
only accessable with the box out of the car.
>QUESTIONS:
>
>Are their any user-serviceable parts in the steering box?
Not really.
>Whats behind the metal plate bolted on top?
The bearing and bearing adjuster which adjusts the output
shaft freeplay
>Is there a part inside I can sandpaper to even the wear?
Not unless you're a miracle worker. These are recirculating
ball steering boxes - somewhat sophisticated. Not agreeable
to home-mechanic intervention.
>How does power steering work?
Very nicely when it works correctly - it's basically an
"assist" not a full-power steering system. For real details
I'd suggest finding a factory manual.
>Thanks in advance for any help.
My only advice is that perhaps you would be best looking
for a low-milage replacement box. By the time it is torn down
and all the parts replaced and adjusted correctly - you're
looking at serious $$$. Luckily they are not a high failure
rate item - so used cost should be reasonable. I am not certain
(Phil Marx??) - but the same box may have been used in other
models ('70s 7-series??).
If it was me - and I'll tear almost anything apart.. I'd
look for a good used one.
Don
PS: Due to the design of the box (recirculating ball and/or
gear/sector) - some freeplay is NORMAL when not on center. It's
the nature of the beast. 1" at 1/4 turn does sound excessive..
so you probably are due for a steering box - but heck, it's
less than a months payment for a new Bimmer..
Don Eilenberger
deilenberger_at_monmouth.com
12.4.4 Power Steering Pumps
From: bt294_at_freenet.Buffalo.EDU (Christopher P. Koch)
Subject: Power Steering Pumps
Dear Dan Lai,
I noticed in your subscription bio that you have had trouble with your
power steering pump/s.
Mine was never quiet but was bearable as a background noise (my
passengers just thought it was a normal BMW sound). However, it has
recently become louder and louder. At idle and low speeds it is by far
the most predominate sound in the car.
I have been shopping this pump the past week and am astounded that this
$80 pump costs as much as $685 for a rebuilt (the low so far is $197 plus
core at Eurasian Parts). I haven't even considered new.
I am wondering if a rebuilt will be quieter (my current pump
works fine) or will be just rebuilt with new seals and
bearings...
Any thoughts?
Yours,
--
Christopher Koch
Tel: (716) 856-5245 Fax: (716) 854-1184
This reply to Alan turned into such a practical treatise on strut
replacement that I decided to waste the bandwidth and post it on the digests
in hopes of helping out some other people.
Besides, it makes me feel important.
I know someone will give me a hard time for having Bilsteins up front, and
Boges in the back. All I can say is " I know, I Know.
The real pproblem is the lifetime warranty on the Boges and my inherent
cheapness. Will I buy Bilsteins for the back? I dunno, seems to handle
real well this way and I'm so cheap.
>>At 10:23 PM 4/11/96 -0400, David wrote:
>>>Hey I've got an 88 735 e 32 w/ bilstiens in the front, and boges in
>>>rear...Low on cash when I bought the rears. I paid 210.00 for the
Bilstein
>>>HDs at Bavarian Auto svc. and wish I had them on the back. The valving
is
>>>quite stiff, but the ride is sweet even in Maine over the frost heaves.
I'd
>>>recommend them to you the ride isn't harsh, the damping is firm .
>>Alan:
>>Bavarian Auto Service lists the Bilsteins at about $222 for the front
pair,
>>and $199.90 for the rear pair, so I guess that prices have gone up a
little.
>>I live in New Hampshire, so I've got the same frost heaves and pot holes
that
>>you do.
>>David:
>>>The Boges aren't a bad choice either, but after putting in the Bilstiens
>>>I'll never go back. It took me about 5 hrs to change the fronts, but I
had
>>>air tools and torches and a strut compresser. The rotors and calipers
have
>>>to come off first.
>>Alan:
>>I have those tools, and I need to do a brake job anyway. I was going to
have
>>the mechanic do it, but upon thinking about it, this is not rocket
science. I
>>DO have some questions, though. Did you remove the calipers completly, or
>>just take them off the rotor and hang them out of the way (with the brake
line
>>still attached)? Also, did you have to take the entire strut assembly out
of
>>the car, or were you able to do the trick of only disconnecting the top of
the
>>strut and then swinging the strut out the wheel well? I've been told that
if
>>this is possible, then I can save a lot of time.
>>I was going to have the car aligned, (just switched back to summer tires)
and
>>the mechanic noticed the leaking strut, so for obvious reasons, he didn't
do it.
>>After I replace the struts and brakes, I'll have the shop do the alignment
and a
>>brake fluid flush (I hate messing with brake fluid...its worth the $50 to
me to
>>have them do it).
>>
>>David:
>>>The rears took a total of 1.5 hrs to change.
>>Alan:
>>I took a look in the trunk and saw where the strut tops are. How the hell
do
>>you get to the bolts? Do you have to remove the back seat? It looks like
you
>>could remove the parcel shelf and speakers and go though there. Any
insight?
>>
>>
David:
Replys to questions.
I think you have to remove the struts from the car. I changed my 2002
struts on the car one time, but you really have to use a lot of brute force
and ignorance to remove the cap nuts on the struts... you could really do
some paint/bodywork damage if(when?)you fucked up!!!
I removed the calipers and let them hang from the hose like you're not
supposed to do. Actually I propped them up on the suspension and they only
fell off and hung by the hose 30 or 40 times. The struts unbolt at the
bottom with big bolts. You have to take the ABS sensor and brake pad wires
off, as well as the brake hose to strut mount bolts(make sure that you don't
twist the brake hoses on re assy. I think I had to crack the flexible hose
to hard pipe line nut to un twist the brake hose . A good set of Snap-on
Metric wrenches gose a long way here, as does a 1/2" Impact wrench.
I have a K-D strut compresser, 30 bucks 15 years ago.. seemed like a lot of
cash then.. paid for itself many times now, although I confess that I just
paid a mechanic $225 to change the front struts in the wife's Mercury Sable!
( Shame on me I only wrench Bimmers, Airplanes, and Boats.. Not enough time
to do it all, but it (paying someone) does feel like cheating.)
Tighten the spring compresser evenly, don't point the springs at your testes
(required car guy sexist comment, ladies don't aim them at any critical body
parts either!) or your face!!! (no I didn't learn this particular lesson the
hard way) Then use an impact wrench to remove the spring and set it aside
gingerly.
Sometimes the compresser can slip around on the spring and the two parts
will end up next to each other. This usually happens when you are whacking
them with a hammer to "even them out"....what a dipshit...un-do them and
take another bite, it happens.
I cut through the caps (Rusted on) with a die grinder, parrallel to the
strut shaft on both sides of the strut (careful not to cut the strut body ,
just the cap) , I used a 2" abrasive cutoff wheel. I then heated them w/
acetelyne torch, (carful not to melt anything)
and removed them with a big-ass stillson pipe wrench and some motherfucking
huge waterpump pliers. It takes a fair amount of hassleing with the strut
compresser to get the springs off, again you could really hammer the paint
in this operation too if you tried to do this on the car. The Bilsteins
have new strut cap nuts as part of the pkg.
Note, I fucked this up...you won't because I already did and am going to
share this with you. The Bilstiens are Internally bump stopped. You don't
need to (can't actually) re-use the bump stops. So, you're sitting there
saying to yourself "I wonder if I need to re-use the dish washers that the
stock bump stops use to bottom out on...Nah.. no bump stops= dished washers=
extra parts." WRONG!!!!!!!!! they rattled. You need these to shim the
strut shaft so it doesn't move in the upper support bearing. (NO I didn't
thke the goddamned things apart again, I took an impact wrench, and with the
weight of the car on the tires, removed the strut shaft nuts and sneaked a
washer in on top...crude but effective.).
Note: re assembly is reverse of...well you know.
Things to watch out for... make sure that you have the rubber spring buffers
in place and the ends of the spring properly seated. It sucks compressing
the springs twice.. how do I know this.. well, you know how it goes.. I
guess patience is a virtue.
Rear struts are a picnic , comparatively speaking. Take the bottom of the
seat out, and then remove the seat back and pick up the parcel shelf cover
to get to the top mounts. (I think) can't quite remember.
BTW the Chilton's All BMW's book, 1970-1988, avalable at Bavarian auto has
this procedure in it. It really is surprisingly good, considering it covers
all models and years.
I hope I haven't scared you off this project.. It is one of the more
satisfying DIY projects you can do. I would be a good time to change to
lowered springs if you want to turn your car into a boy racer ride. I opted
not to, as lots O' suspension travel is good in New England. I didn't want
to loosen any fillings. I did lower the front end 1/4 " with thinner spring
bushings from Bavarian... Almost unnoticeable.
The other note is that It takes significantly longer on the first strut than
the second....you really learn from experience.. I can do a VW rabbit in
about 45 min a side now, and I m not a professional mechanic.
I just bought a set of Pirelli t4000 tires, v rated, 60,000 mi treadware
warranty at NTW
for $640 balanced, on the car, all warrants and lifetime balance. Then I
drove 85 mph in super heavy rain and liked it( no hydroplaning, quiet etc.
Didn't hit anything either! COOL!)
Time will tell how I like them but my initial impression is good.
>88 e32
>'55 Piper PA-22
>84 Grand Wagoneer(so big!)
>89 smallblock powered 21'Wellcraft
>Notice I didn't mention the Mercury Sable...cheap, and lots of boneyard
parts avalable down the street.
Any resident experts out there? I've got a 81 745i with anti-lock that are
mush.
Is there an air bleed on the anti-lock assembly? What's the official service
proceedure for bleeding these things? Please e-mail directly any reply's
because I'm burried and it will get lost otherwise!
On Sat, 13 Apr 1996 bmw-750_at_transarc.com wrote:
> Brian wrote:
>
> Another problem I've run into is a strange metallic clicking noise that
> occurs under hard cornering to the right..... The harder I corner the
> louder the clicking.
>
> Thanks for the advice but I neglected to mention that the noise seems to
be
> coming from the right front wheel area. Any more advice would be
appreciated
> from anyone that has a clue to what this might be.
>
> The Other Brian
> 1991 750iL
>
Dear Brian,
One of our local chapter members had this happen on her 735i - and it
turned out to be some road debris wrapped around her anti-lock sensor
mechanism on the passenger front tire. The sensor is somewhat like a
gear sprocket from a bicycle with an inductive pickup.
Unfortunately in her case, she waited too long (about two weeks) and
the debris chewed up the "gear sprocket" and damaged the sensor itself.
Both had to be replaced.
Chris Koch
> I have a noise that seems to be coming from the left front part of the
engine
> compartment, whenever I hold the brake pedal down. It's an intermittent
clicking
> sound that can be felt on the brake pedal. Is this a power assist servo
problem?
> Any clues?
>
> Jack
>
Dear Jack,
Just wish to confirm that my 750iL has had this same noise during my
entire ownership. I tried three Dealerships and the gurus at the
Oktoberfest without finding an explanation...
I figure it has something to do with the servotronic steering or perhaps
the braking system (pressure regulator?). I too feel it in the pedal.
Sure is irritating - especially since only you and I seem to hear it!!!
Chris Koch
12.5.3 Brake Pressure Warning Message
From: Fred Vu <fredv_at_seeus8.com>
Subject: Break Pressure Woes
>
> From: Guy Therien <Guy_Therien_at_ccm2.hf.intel.com>
> Subject: Brake Pressure Warning Message
>
> I am getting a "BREAK PRESSURE" message in the MID of my 91 750iL. Despite
the
> owners manual, it's not clear to me what can cause this. There are no
mechanical
> symptoms, the brakes work fine. I thought that I might be low on the brake
> booster / power steering fluid. Does anyone know what type of fluid to buy
and
> how to check the fluid level? It wasn't completely obvious to me.
>
> Guy
>
My '88 750iL had the same symptom. The problem was due to the defective
brake
pressure switch. The parts replaced are:
61-31-1-362-977 Thrust Switch $23.63
34-33-1-150-922 Switch/Oil Pre $22.83
I am no mechanics, the above parts number and prices were how much the
dealer
charged me.
-fredv-
BTW, the diagnostics and labor + the parts = 89.06.
12.6: HVAC
12.6.1 Fan Control
From: Jeff Moser <jrmoser_at_nando.net>
Subject: Re: Fan Control Question
Doug,
The following is a repost of an answer that I gave a few weeks ago about the
HVAC fan control box. If I can help you further, let me know.
Jeff Moser
>
>I have had a quick look at my ETM (1989 E32), and it seems that the
resistor that you are talking about is really a thing called a "Final Stage
Unit". The "FSU" is actually a little more than just a plain resistor. It
contains a transistor and associated electronics that allow you to have
infinitely variable fan speed, and it also contains a relay which kicks in
when you turn the fan switch all the way on. If you are interested, it is
located behind the LEFT footwell (console) panel of the passenger side, and
it appears to be on the order of a pack of cigarettes in size.
>
>(All of the above assumes that your 1988 is the same as my 1989.)
>
>If you do have it replaced, I would love to have the defective piece if
your dealer will give it to you. Being an EE, I just love looking inside
these "little black boxes".
>
>Jeff Moser
Doug,
I think I was the one who told you about the location of the HVAC fan
control. I hadn't actually seen it myself when I described it's location to
you. Since that time, I have actually removed the one from my car (in
search of the non-existent microfilter), so maybe I can help further.
Remove the left side console panel in the passenger footwell. (You may need
to remove the glovebox also). In the area of the removed panel, you should
see a wiring harness. Trace the harness toward the firewall to the
connectors, there should be three. Two connectors plug into the HVAC main
control unit which is located near the firewall. The third connector plugs
into the HVAC fan control, which is located just behind the main control
unit. (Hint: The fan control connector is a different type of connector
than the other two).
Now, hopefully from the description above you have found the HVAC fan
control. Remove the harness connector from the fan control. The only part
of the fan control that is visible at this point is just the end, as most of
it is buried inside the evaporator housing. Remove the two screws about 1
to 1 1/2 inches above and below the connector on the fan control, and slide
it out of the evaporator housing. When removed it is an aluminum heatsink
with 4 power transistors on it which is about a foot or so long.
Regarding the fan module....look on the passenger side after you drop or
remove the glove box. You will see a 3'' oval/rectangle sized plastic unit
secured with 2 phillips head screws and a wire connector going to it. Remove
the screws and pull the unit out towards the passenger door. The unit is a
giant circuit board with power transistors on it about 2 feet long??? I
found bad solder joints on my unit and resoldered it( it used to only have
the fan on high) It worked for about 2 years and last week it fritzed
again...now my fan wont shut off....Oh weel so much for the Gremlins from
Stuttgart. Ed
So I have this blower which has two speeds, full on and slightly
less than full on.
With help from the list I locate and yank the blower control. Circuit
board with a major heat sink. Little analog bits and 4 big power
transistors.
The problem was one of the transistors had shorted collector to emitter.
This was obvious when I drilled out the rivets holding the assembly
together and found the back of one of the transistors burned brown. The
failure was caused, I suspect, by a quality problem in manufacture. It
seems whatever they used to coat the curcuit board got between the
transistor-to-heat sink thermal path and the transistor just couldn't
get rid of that much heat by itself.
The transistors are darlington, I suspect, bacause the base current for each
transistor is supplied through a 4.7K resistor. When the motor is running
at near full speed the current through the board is about 12A, so each
transistor carries about 3A of that. So there has to be a pretty big beta
given that the base current is probably only about 2.5mA.
The power transistors have been potted in some major strong epoxy or I
would yank them all and replace them, using some good heat sink grease
and threaded fasteners instead of the Al rivets the factory used.
Instead, I ordered a replacement board from Programa. $190 plus $50 core
charge. As a temporary fix I used my dremel tool to cut through the epoxy to
cut the leads of the offending transistor. Works fine now but I'm sure
one of the other transistors will give up pretty soon, due to the increased
current load.
While under the dash I was able to see the stepper motor in the area behind
the raido. The plastic mount has broken off, which explains why the
passenger
side air vent acts funny. I was able to work the broken part out of the
dash.
When the new board gets here tomorrow I'll pull the radio and attempt to
glue
it back in. Should be a prety large PITA.
I really like this car but there is just way too much complexity and poor
quality in the HVAC system. And the seats. And the driveshaft. Pretty good
stuff other than that.
Got the rebuilt fan control board from Programa. They did a nice
job of it. Wish I knew how they got the epoxy off of the PCA.
Anyway, installed it and it works fine.
Fixed the broken stepper motor mount behind the radio. Now the
passenger side A/C is as cool as the driver's side! This was
not easy. Several times I almost resorted to ripping the dash
off to be able to get clear access to the mount. Not fun at all.
Replace the burned out bulbs in the OBC while I had access to
the OBC ejector. Pretty rude of them to wire the bulbs in series
so the entire display goes if one bulb burns out. Anyway, it is
back in with a good display but I must have disturbed some wiring
there as it forgets the date/time and other accumulated information
when the car runs for a bit. The folks a Programa think a fuse or
a connector is to blame.
Doug
12.6.2 1989 E32 Microfilter, Glovebox, HVAC Fan
From: Jeff Moser <jrmoser_at_nando.net>
Subject: 1989 E32 Microfilter, Glovebox, HVAC Fan
Well it was such a nice day today, I decided to go outside and screw around
with the car for a little while. I decided it was time to check the
infamous microfilter out and see what condition it was in.
I followed the procedures listed in the E32 repair manual, and removed the
glove box, the HVAC control unit, the Final Stage Unit, to get down to the
point where the microfilter actually is supposed to be. Lo and behold, it
was then that I discovered that my 1989 E32 is NOT equiped with a
microfilter! Well, I guess you live and learn. I don't know when the E32's
started having microfilters, but my 1989 doesn't.
One interesting thing that I did learn while undertaking the above was that
the glovebox does more than just open downward. While trying to remove the
gas cylinder from the glove box, I accidentally pulled on the front of the
glovebox. The darn thing slid out like a drawer! When the glovebox is
pulled out, it makes it a darn lot easier to access the contents. While I
am no E32 expert, this is one trick that the car has that I never knew
about.
Also, for you folks with HVAC fan troubles, I actually got to see the "$300
Fan Resistor" (Final Stage Unit) today while screwing around looking for the
stupid microfilter. This "$300 Resistor" consists of 4 power transistors
mounted on an approximate 3" by 12" aluminum heatsink. It also has a small
black plastic box and connector on one end. The aluminum
heatsink/transistor end is inserted directly into the HVAC ducting and is
cooled by the airflow through the duct. It looks like it would be very
possible to easily replace these transistors if one went bad. If anyone
wants help in trying this, let me know. I once heard someone describe this
"Final Stage Unit" as resembling a Sword, and it darn sure does look like
one.
Jeff.
(Am I the only E32 owner in the world that did not know how to properly work
the glovebox?)
From: K & J Moak <kmoak_at_erols.com>
Subject: HVAC (750)
OK, I did some playing around and found out some interesting things. You
folks with 750's, follow along and try it yourself and let me know what
happens in YOUR car.
First, as a recap, I don't think the left-most HVAC airflow button (on
either side) is working properly. The AUTO button and the footwell button
work fine, but when I push the left-most button (supposed to send air to ALL
outlets), I get a little flow out of the footwell vents, but nothing out of
the defrost vents.
OK, first I tried turning the A/C switch off, and guess what, all of a
sudden the ALL VENTS button functions fine...air out of all vents. Push the
A/C button, and the defrost vents shut off again. So, turned off A/C and
then tried the other buttons....in all positions with the A/C off, get small
amount of flow out of the defrost vents. Hit A/C, and defrost vents shut
off again in all button positions (except defrost setting which works just
fine).
Then, I shut off the engine to see what would happen as the vacuum bled off.
Well, either that vacuum pump has one hell of a reservoir, or those flap and
shutters are operated electrically on the 750's, becasue after 15 minutes of
playing around with the engine off (key in position 2), the HVAC vents were
still 100% functioning.
So, lots of questions for 750 owners.....
Does your system work the same way?
Is the system electrically or vacuum activated?
If vacuum, how can it operate for 15 minutes after engine shut off.
Other cars I've owned with vacuum operated valves, flaps, vents, etc. are
only good for about 2-4 airflow changes before all of the vacuum is bled
off. Maybe the pump works off electrical power and so is active with the
key in position 2? (Naah..can't be the case, can it?)
I've noticed much of the mail and the latest "registry issues" discuss
many HVAC, electrical problems and parts that fixed them from
PROGRAMA.
This may be in the FAQ but here goes anyway.....
POSSIBLE PROBLEM:
My HVAC in Auto mode may be malfunctioning. I'm not really sure.
SUMMARY:
When the dial is set at the first detent (low) if works well at a very
low, cold flow. In the last detent (high) it works but does not blow
very cold air.
In the mid/variable position it works most of the time. However,
sometimes it will just stop blowing for "a while" (usually when I'm
stopped and no air is moving). Note: When the outside temp is 105 F
and the inside temp starts to exceed it, I NEED the A/C.
If I manually change the setting to HIGH it works well, but does not
stay cold for very long.
QUESTIONS:
Is this normal behavior for an 88 750iL HVAC system?
Will the Programa replacement part, that several digester's have
installed below the radio, fix the climate control/fan speed problem?
Is it worth having the dealer/Dinan have look?
Will I have to re-mortgage my house to pay for the fix/replacement?
Any help is greatly appreciated.
Thanks,
Paul Jones
88 750iL
Paul Jones wrote:
>
> POSSIBLE PROBLEM:
>
> My HVAC in Auto mode may be malfunctioning. I'm not really sure.
>
> SUMMARY:
>
> When the dial is set at the first detent (low) if works well at a very
> low, cold flow. In the last detent (high) it works but does not blow
> very cold air.
>
This could be caused by a fault in one of the flapper controllers or by
low gas in the A/C system.
>
> In the mid/variable position it works most of the time. However,
> sometimes it will just stop blowing for "a while" (usually when I'm
> stopped and no air is moving). Note: When the outside temp is 105 F
> and the inside temp starts to exceed it, I NEED the A/C.
>
Now this sounds like the fan control board. The board (some call it the
"sword" because that is what it looks like) has a thermal limiter on it
and it might be shutting down.
>
> If I manually change the setting to HIGH it works well, but does not
> stay cold for very long.
>
Do both driver and passenger vents blow air at about the same temperature
when this happens? If so, it is probably not a flapper controller because
this would require both the driver and passenger sides to fail at about the
same time.
>
> QUESTIONS:
>
> Is this normal behavior for an 88 750iL HVAC system?
>
Don't think so.
>
> Will the Programa replacement part, that several digester's have
> installed below the radio, fix the climate control/fan speed problem?
>
Possibly.
>
> Is it worth having the dealer/Dinan have look?
>
Diagnosis shouldn't cost too much, so that sounds like a good plan.
>
> Will I have to re-mortgage my house to pay for the fix/replacement?
>
Not for the fan controller. Anything other than a A/C recharge is probably
going to be expensive. Take it in a let them tell what it is going to cost.
A '91 850i 6-speed belonging to a friend has developed some strange
squeaks from the various flaps and valves in the climate control
system. When the system is set on automatic and the brain decides to
adjust the air flow to stabilize the temperature, you can hear the
flaps squeak as they move.
His dealer has been no help with trying to lubricate them - the car
is out of warranty... I would imagine the ducting is a quite a
labyrinth and the valves would be difficult to get at. Does anyone have
any thoughts?
My suggestion was to drown the squeaks out with one of those new
Stebro stainless exhaust systems from John Dimoff (details available
from the addresses below, not above - that5 one expires on Friday, July
5.), but he thought he would wait until the factory exhaust expired.
12.6.4 Water control solenoid 7er heat
From: powdah_at_mainelink.net (David Leonard)
Subject: Water control solenoid 7er heat
You Wrote:
From: Steve Johnson <SJOHNSON_at_clitho.com>
Date: 16 Apr 96 16:00 cst
Subject: 91' 735i A/C Heating Problem
Hi Folks,
My '91 735i has a problem where it will not stop pumping heat out of the
side defrosters no matter where the A/C and Heater controls are set. I can
have everything off and it will still lightly blow 150 degree air out of
these vents and the rear floor vents.
Someone told me this is a computer problem with the heating cooling system,
but the dealer just says "never heard of it". I find that to be
comfortable, I have to run the A/C in 50 degree weather to offset the high
heat output. In the summer, the AC cannot overcome the excess heat good
enough to cool the car, and when it is first turned on I get a friendly
BLAST of VERY HOT air from the A/C vents.
Any sugguestions for me to pass on to my service guy would be VERY much
appreciated!
Steve Johnson
Kansas City, MO
I Reply
"There is a valve located on the drivers side firewall. It has two heater
hoses and two solenoids controlling the h20 flow to heater cores. If these
coils are not getting any power, the go to full on.. hence full heat. The
trouble is probably in the wiring/switches. If you make up a jumper wire
you can dump power into the control valve and see if the valve closes. If
you make a good setup you could leave it on all summer, and take it off in
the winter.
The body computer normally pulses this circuit on and off by making and
breaking the ground to this circuit depending on temp setting.
The dealer fixed mine(88e32) In one hour, and charged me60 bucks. He
jumped the swithc on my panel and its fixed.
I have had various electronic glitches with my 92' 735i that have all the
signs of firmware bugs. For example, last night I get a "1 Brake Light"
message, but the brake lights are fine, and after the message clears my trip
meter goes to zero (000.0). For that matter, my trip meter has gone to zero
several times of late for no apparent reason. I have also had the problem
where the engine is hard to start and I get the "Check Control" message. I
suppose it is possible that I have a hardware problem that is causing these
odd behaviors, but it feels more like code problems to me. Has anyone heard
of BMW providing firmware upgrades to the computer system on the car? If
so,
where can I get it?
Thanks
Dave
> From: Dave Tostenson <davet_at_pioneer.rose.hp.com>
> Subject: Firmware Upgrades?
>
> I have had various electronic glitches with my 92' 735i that have all the
> signs of firmware bugs. For example, last night I get a "1 Brake Light"
> message, but the brake lights are fine, and after the message clears my
trip
> meter goes to zero (000.0). For that matter, my trip meter has gone to
zero
> several times of late for no apparent reason. I have also had the problem
> where the engine is hard to start and I get the "Check Control" message.
I
> suppose it is possible that I have a hardware problem that is causing
these
> odd behaviors, but it feels more like code problems to me. Has anyone
heard
> of BMW providing firmware upgrades to the computer system on the car? If
so,
> where can I get it?
>
Dave,
While I don't think these problems are firmware, let me tell you about
that anyway. Each car is manufactured at a certain point in time with
firmware that is EPA/DOT certified at that moment. I wanted to upgrade
my computers (three: main & two engine control) to newer rev software but
wasn't able because the certification is only valid for your batch of
750s manufactured during that period. When my computers had to be
eventually replaced, the units had to be burned in with my old software
in Germany. Took many weeks to get the job done...
C.P. Koch
> From: Doug Donsbach <dld_at_symtec.com>
> Subject: Programa
>
Programa, Inc. (407) 338-8843 fax: 338-8447
Dave - my '89 750iL has been having very similar problems (trip odometer
resetting itself and bogus warnings on the dash display). I have it in an
independent shop now to get this and some other things fixed. They have done
a
lot of diagnostic work and tried replacing a couple of relays without fixing
these particular problems. (They did trace down and fix some other
electronic
gremlins with minor parts costs, so I tend to trust their integrity, unlike
my
local BMW dealer, who just wanted to replace every expensive control unit in
the car.) The independent shop finally concluded that it needs a new
"instrument cluster control board" or "SI board", which is a $750 part (the
BMW dealer wanted $900 for the same part). It's on order now and I should
know
in a week whether the fix works.
I've read in some of the BMW publications that many of these kinds of
problems
are caused by broken circuit board connections, bad solder joints in the
control board, or even a bad NiCd battery. Unfortunately I tend to make
things
worse when I work on complicated machinery <g>, so I'm not going to try to
pull the card out myself and mess with it. I think the BMW Enthusiasts
Companion from Bentley Publishers has instructions for pulling this card and
fixing some standard problems, if you have a knack for this kind of thing.
Dave - just to follow up on my previous message: my mechanic did install a
new
instrument cluster motherboard on my '89 750 and my problems with the trip
odometer, bogus warnings, etc. have gone away. I inspected the old board and
there was nothing obviously wrong with it, but it is a fine-line circuit
board
with lots of chips so it would be really hard without diagnostic equipment
to
track down the problem.
-Kim
12.7.2 Subject: Replacing OBC Light Bulb
Hi fellow 7-ers;
The light bulb in my OBC has been going off and on, it seems like
it is ready to go or it is loose. I tried to pop the OBC off but I cant get
it loose. Could somebody post the steps in taking out the OBC?
I recently purchased a '91 735il with about 60,000 miles on it. It ran fine
until last week when the poltergeists invaded: No power, wouldn't idle, EML
and ASC lights on intermittently. The dealer futzed around for a while
clearing the 15 faults displayed by the diagnostic computer and finally
installed an air flow meter. That didn't fix it so now they think the EML
module needs to be replaced. As this is a $1,000 part, I'm wondering if a)
anyone out there has any experience with this sort of nonsense; b) any
alternatives to shelling out a grand; c) are there any other problem areas
that might cause these symptoms (preferrably a $1.98 part that can be
replaced without tools). I'm resigning myself to the $1,000, but I do like
to know that there are no alternatives.....
I recently went through a similar problem. I have an '88 750IL
with several performance upgrades and ~ 122K miles. About 2
weeks ago, my EML light came on and the 750IL lost significant
power. I went to a local BMW dealer and, like yours, cleared
several faults. However, the service dept. indicated that I
may need a new DK motor ( there are 2 in the 750IL ) and he
asked me to monitor the car behavior. As I approached my house
( ~ 25 miles from the dealer ) the EML light came on and power
loss was exhibited. The next morning I returned to the dealer
and left the car there. Sure enough at 12:00 pm I got a call at
work from the dealership indicating that I indeed did need one
DK motor ( Part: $800.00 + Labor: $150.00 ). Since then the car
has been running fine.
Incidently, the DK motor, according to the dealership, is a
motor that control/manages the throttle in the engine. In my
750IL, one of the two dk motors had gone bad which resulted in
inappropriate air/fuel mixtures in the engine.
Hope this helps. If indeed this is your problem, I would
definitely bite the $1000.00 and let the dealership fix this.
'88 750IL Sanjeev Saxena
12.7.4 Tachometer not working
> From: CELLGURU_at_aol.com
> Subject: Tachometer not working
>
> The Tach on my 84 745i has not worked since I purchased the car. The car
This is very common! The reason is that at 30K miles, the mechanic is
instructed to pull the oxygen sensor wire from the back of the instrument
cluster. If the mechanic isn't careful, it is very easy to pull the
identical wire next to it (different color, brown if I remember) off at
the same time. Bingo, no tach.
Chris Koch
Tel: (716) 856-5245 Fax: (716) 854-1184
12.7.5 Mirror Tilt
From: Alan Legerlotz <alan.legerlotz_at_ljo.dec.com>
Subject: Mirror Tilt
I have a situation with 7 where the mirror will tilt irratically, no matter
the
position of the "selector" switch.
This happens more in the wet than in the dry. I'm assuming its a ground
connection of some sort, but perhaps someone on the list knows more about
this.
Is there a relay or control module that could be causing this?
-Al
1990 735i
12.7.6 Retrieving Motronic Codes From Your Car
From: RiskIsBack_at_aol.com
Subject: Retrieving Motronic Codes From Your Car
Here is the short and sweet of it:
Place the ignition on the start position, but do not engage the starter
(
all check lights will be on)
Fully depress the accelerator and release. Do this cycle five
times in a row. The top-to-bottom-to-top-again cycle should take about one
second.
The check engine light will now begin blinking, beginning with code 1224,
which is the start sequence. The check engine light will flash one time and
pause for ~1 sec, flash twice and pause for ~1 sec, flash twice and pause
for
~1 sec and flash four times and pause for ~1 sec. Then it will flash on for
~2 sec. each flash sequence indicates the code number. Each code is four
digits long (i.e. 1224, steady light, 1223, steady light). A second code
2224 indicates the start sequence for the second Motronic computer in 12 cyl
engines (like our beloved 750iL). Error codes for the second computer begin
with 2, such as 2223, 2134, etc.
HAVE FUN, IT WORKED FOR ME, LET ME HEAR SOME FEEDBACK!!!!!!!!
I will download the codes later for your reading pleasure.
12.7.7 climate control lights
> From: "Prakash T. Maggan" <74514.2255_at_CompuServe.COM>
> Subject: RE: climate control lights
>
> Hi Philip,
> One of my lights has burned out also. The fan speed dial's light
> has burned out. My mehcanic said that the whole board would have to be
replaced
> as the bulb is not replaceable. I didn't even bother to find out the
price
of
> the board. But if you do come across the price, please let me know. I
told
my
> mechanic if he though that the board would cost more than $5, I don't want
it.
>
> Prakash Maggan
> '92 DINAN 750iL
Dear PM,
It is really very easy for any transistor head to solder in new flea
lamps. Radio Shack has two for $1.99 plus tax.
All this talk about bulbs has encouraged me to go outside and see if the
squirrels have dug up our tulips. Usually they beat the weather - I hope
that Buffalo will warm up by mid-May.
Chris Koch
12.8: Misc
12.8.1 Official BMW Cruise Diagnosis (long and taken from E28, but the
Subject: <E28> Official BMW Cruise Diagnosis (long)
This is the check procedure from the BMW shop manual have.
The first parts are real simple, but the later do have some insight.
Looking at factory repair manual:
The cruise works "from about 22mph to almost maximum road speed".
"The system switches off automatically when the actual road speed drops
below
the set road speed by approx. 15%."
"When the road speed picks up by 6 to 8 km/h (4 to 5mph) more than the set
road speed, the fast seperating clutch opens and the throttle goes into the
idle postion. If the road speed goes back to the set value, the clutch will
close again."
"Adjust cable with knurled nut until there is play = 1 to 2 mm (0.039 to
0.079")."
"TROUBLESHOOTING CRUISE CONTROL
"Test Requirement:
Battery charged - battery voltage okay.
Specified multimeter functions (e.g. M 01) are in reference to the BMW
SERVICE TEST. the following multimeter functions are required: 01/06/14. The
following test procedures do not include sources of defect, which are
outside
of the electronic cruise control system.
"Check fuse no. 12 and contact of fuse.
Fuse and contact okay?
no--> Replace fuse. Clean an bend fuse holder.
Yes--> Continue
"Check bulbs of stop lamps and their contact.
Bulbs and contact okay?
no--> Replace light bulbs. Clean and bend contacts.
Yes--> Continue
"Check cable adjustment.
Cable adjustment okay?
no--> Adjust cable. Replace cable, see 65 71 040 in Repair Manual
Yes--> Continue
"Check cable and strap of operating motor for damage and easy movement.
Cable and strap okay?
no-->Replace cable or operation motor
Yes--> Continue
"Check adjustment of brake and clutch cable pedal switch.
Adjustment okay?
No--> Adjust brake and clutch pedal switch. See Group 35 of Repair Manual
Yes--> Continue
"Check all plugs (see wiring diagram) and wires for tight fit and damage.
Plugs and wires okay?
No--> Repair or replace plugs and wires.
Yes--> Continue
"Connect ohmmeter (M 06) between ground and wire (23) on disconnected
control
unit plug.
Ohmmeter should display approx. '0' ohm.
Resistance value okay?
No--> Correct ground connection according to wiring diagram.
Yes--> Continue
"Pull off plug on control unit.
Connect voltmeter (M 01) between ground and wire (1) on disconnected control
unit plug.
Turn on ignition.
Voltmeter should display operating voltage* for control unit.
Voltage value okay?
No--> Correct power supply according to wiring diagram.
Yes--> Continue
"Connect voltmeter (M 01) between ground and wire (2) on disconnected
control
unit plug.
Turn on ignition.
Voltmeter should display operating voltage* for control unit.
Voltmeter should display approx. 0 volt.
Selector lever shitch pressed in 'off' direction - voltmeter should display
approx. 0 volt.
Voltage values okay?
No--> Check and repair 'selector lever switch - control unit' plug and
wires.
Replace selector lever switch.
Yes--> Continue
"Connect voltmeter (M 01) between ground and wire (4) on disconnected
control
unit plug.
Turn on ignition.
Voltmeter should display approx. 0 volt.
Selector lever shitch pressed in 'constant' direction - voltmeter should
display battery voltage.
Voltage values okay?
No--> Check and repair 'selector lever switch - control unit' plug and
wires.
Replace selector lever switch.
Yes--> Continue
"Connect voltmeter (M 01) between ground and wire (5) on disconnected
control
unit plug.
Turn on ignition.
Voltmeter should display about 0 volt.
Selector lever shitch pressed in direction 'call'.
Voltmeter should display operating voltage*.
Voltage values okay?
No--> Check and repair 'selector lever switch - control unit' plug and
wires.
Replace selector lever switch.
Yes--> Continue
"Connect voltmeter (M 01) between ground and wire (9) on disconnected
control
unit plug.
Turn on ignition.
Voltmeter should display approx. 0 volt.
Voltage values okay?
No--> Replace brake pedal switch See Group 35 of Repair Manual.
Yes--> Continue
"Connect voltmeter (M 01) between ground and wire (9) on disconnected
control
unit plug.
Turn on ignition.
Operate brake pedal.
Voltmeter should display control unit operating voltage*.
Voltage value okday?
Yes--> Skip to freq meter question
No-->
>Check stop light switch.
>Pull off both plugs on stop light switch.
>Connect ohmmeter (M 06) on stop light switch.
>Operate brake pedal.
>Ohmmeter should display approx. 0 ohm.
>No-->Replace stop light switch.
>Yes--> Continue
>"Check clutch switch.
>Pull off both plugs of clutch switch.
>Connect ohmmeter (M 06) on clutch switch.
>Ohmmeter should display approx. 0 ohm.
>Operate clutch pedal.
>Ohmmeter should display 0 ohm.
>Values okay?
>No-->Replace clutch switch.
>Yes--> Check wires, repairing if necessary.
"Connect frequency meter (M 14) on wires 3 and 6 on disconnected control
unit
plug.
Lift car.
Start Engine.
Run briefly to speed of about 50 km/h (30mph).
Frequency meter should display frequency*."
Okay?
No-->Check speed tranmitter for speedometerm see Group 62 of repair manual
>No--> Check wires, repairing if necessary.
Yes--> Continue
"Connect control unit plug again.
Following tests are made on 7-pin plug for 'control unit - motor'.
Connect voltmeter on connection (4) and on connection (3).
Turn on ignition.
Voltmeter should display about 8 volts.
Voltage value okay?
no --> Replace control unit.
Yes--> Continue
"Connect voltmeter on connection (3) and connection (7).
Turn on ignition.
Voltmeter should display voltage.
Voltage value okay?
no --> Replace motor
yes [continue]
"Disconnect 'control unit - motor' 7-pin plug.
Connect connection (1, white) on ground.
Connection connection (6, green) on B + (12 V).
Clutch must be heard to switch.
Clutch switching?
no --> Replace motor
yes [continue]
"Connect ground on connection (2, blue) and B + on connection (5, black) of
7-pin plug on motor.
Motor must be heard to run.
Motor running?
yes --> Replace control unit
no --> Replace motor."
My '87 535 had top be towed off the highway this morning after it died
while cruising _at_ 65-70mph.
I first felt a sputterring and intermittent power loss and then followed
by total power loss. No dash lights actually came on during the power
loss until I had pulled off the road.
I was able to restart the engine while sitting at the side of the road
but it died again as soon as I put it under load (started to release
clutch). I tried to restart again but it failed.
After sitting for 10-15 minutes I was able to restart the car and it
idled for about a minute before dying again... this time I had not put it
under any load.
Additional history & background:
-These same symptoms presented themselves yesterday while again
driving at highway speed. The engine sputtered, then lost power
momentarily but then regained power. Symptoms did not reappear
rest of day yesterday or first 3-5 miles of driving this morning.
-I noticed a burning smell inside the car this morning immediately
after pulling the veh8icle off the road. I checked under the hood
and could not find any evidence of electrical problems. The burning
smell was only evident inside the car.. not under the hood.
- For the past several weeks I had been feeling that engine had a "lean"
surge at light and moderate throttle... below 3500 rpm. At a constant
throttle opening it felt as if the engine would get a temporary surge
and then diminish. No surge was evident at idle.
- I replaced plugs, cap/rotor approximately 5K miles ago and the fuel
filter I replaced just 2 weeks ago.
Any help with diagnostic tips would be greatlyt appeciated. I certainly
seems to be a fuel delivery problem but I'd like to isolate it to the:
pump relay, sensor?, tank pump, primary pump.
Caught your posting on the Digest. Your symptoms suggest a classic case of
needing an oxygen sensor. Surging & hesitation. Surging could also be the
Idle control valve under the hood. Checking that requires a minivoltmeter &
a Bentley Manual. I'd start with the o2 sensor & go from there. New sensor
assembly runs $135-150. We sell a EZ-Fit Tip Kit for $59.95 (New BOSCH).
For more info see our Web Page listed below. Idle Control Valve New BOSCH
$89. If the car has (miles) replace both & move on w/ your life. Any ? call
or E-Mail back we'll be happy to help you. Rodd Sidney
Rodd Sidney BMW Dealer Marketing Web Page
bmwrodd_at_dzn.com http://www.dzn.com/global/bmw.htm
12.8.3 Checklist
> From: Tom Neice <tneice_at_iadfw.net>
> Date: Fri, 28 Jun 1996 20:27:41 -0500
> Subject: Dinan Chips
>
> I recently purchase an 83 733i. All records, 145k miles. This car
> replaces a 1990 Mercedes 560SEC, and frankly, I'm having more fun
> driving. Can anyone tell me if you can get a Dinan chip to upgrade
> performance? Should I leave well enough alone?
>
> Tom Neice
>
> 83 733i 145k
> 83 MB 300SD 240k
> 90 MB 560SEC (gone, but barely missed)
Dear Tom,
Personally, I would start working on your (new) 733i in other areas
before getting into increased performance. I'm willing to bet that a
good flush of all fluids (see synthetic comments above) including engine,
transmission, axle, brakes, steering, A/C and cooling is in order. I would
first drain and replace the lubricants with standard stuff, run it for two
weeks and then replace once again with the synthetics. Then, since the
synthetics will find every leak, go through everything and replace the
necessary gaskets and seals. Change all filters (gas, oil and air).
Then, go through the engine systems. Cap, rotor, wires, plugs. Mass
flow and idle controls - do they work freely, are they clean, are the
electrical contacts clean and lubricated (silicone spray)?
How about brake pads, calipers, rotors, tires?
Did you replace all of those little missing or broken plastic pieces
inside and out? Do all systems work? Windows, locks, seats and sunroof
all probably at least need lubrication. I take all of mine apart, clean
and relube.
How is the body work and trim? Seats, doors, headliner, rugs?
OK, now you have a straight car, a basis to which you can now play and
add as many questionable "improvements" as you wish.