From digest.v9.n730 Sun Dec 20 23:32:36 1998
From: Pearson-Franks Family <pearsonf_at_halcyon.com>
Date: Sun, 20 Dec 1998 21:57:30 -0700
Subject: <E28> Purchase/Maintenance Observations, Part 2 of 3
Part 2 of 3 of my long post.
More E28 look-for's:
3) Oil and Oil Leaks
- Visually, 'fresh' oil will appear a clear brown, as you know.
Black just means old, any cloudy or white means water, which
is very BAD, 'bad' being defined as like crossing two
anti-proton streams resulting in the destruction of the
universe as we know it.
- Check under oil filler cap: there should be no cloudiness, and
gives you an idea of internal cleanliness (which is good).
- The owner's manual says it is 'OK' if the oil pressure light
comes on 'at times', like idling when hot, but should go out
when revved. Drives me crazy if it comes on at all!
- The oil pressure sender is a frequent leaker. The leak will
track down the side of the engine and drip off the lowest
point of the bell housing, so don't confuse it with other
- The pan gaskets occasionally 'creep' out of their space and
self-destruct. If you go in to replace this on a high miles
motor you intend to keep, replace the oil pump (and probably
the sprocket) at the same time. $150ish, and well worth it.
4) Other Engine Compartment Stuff
- All fuel lines are suspect by 100K - especially the short hank
to the cold start injector at the lowest extreme of the
intake manifold, for some esoteric reason. Don't use cheap
stuff! Buy the BMW 8 x 13 mm stuff from one of many sources.
- Vacuum leaks are a major hassle. Prime symptom is rough idle,
flat spots at mid revs, may also be fuel pressure regulator.
Do easy candidates first: put an o-ring in one of the grooves
in the dipstick top. Put clamps on the hoses to the valve
cover and idle motor (if E28). Replace the hard-as-rock
hoses in general. Replace the fuel injector o-rings.
- Look at the brake fluid. Black is _bad_, but at least means
it wasn't being topped up each week (see 'slave' discussion
below). Color of the brake fluid is a very good indicator
of the general tenor of the maintenance regime for the car.
If it is black as pitch, indicating it is _not_ getting the
yearly replacement the anal-among-us so lovingly do, check
more closely for all the other maintenance opportunities.
- Lots of things can make this baby idle rough; already
mentioned vacuum leaks. Mucho covered in FAQ's. Best I
have seen is by Sam Lin <Sam_at_cmdexsvr.cmd.com> for a copy.
- Plug wires are a 100k consumeable in my book. Cleap insurance,
can help several marginal symptoms, lotsa sources, $80ish.
5) Tranny and Clutch
- No experience with the 4-speed auto, so no comments.
- The Getrag 5-speed should enter all gears smoothly -
they are not especially prone to synchro failure in normal
operation (i.e. not auto-x'd) but most are 'notchy', kinda
hard to push into gear, especially when rev's not synched,
but easily improved by putting in Redline MTL tranny oil.
- Every 100K+ Getrag I've seen leaks. From the rear is OK
but messy - shift shaft seal fails, soaking back of tranny.
Output shaft seal weeps, no major heartache. Seam between
front and rear half of tranny case weeps, wets bottom of
tranny, but no sweat. Saving the best for last: If there
is oil (not brake fluid, see below) coming out of the drain
hole in the bell housing, either the tranny front seal is
leaking, (likely) or the engine rear main (possibly). This
is _bad_ (see definition above) because the clutch is not
designed to be oil-bathed, and will tend to chatter and fail.
Seals are $5-$10 each, clutch trio (pressure plate, clutch
disk, throw-out bearing) are $300ish. All quite doable, but
considerable labor, dropping exhaust, removing driveline.
- Clutch pedal should depress smoothly, although with a lot more
force in the 535i than the 528e or a 3-series. Should not
hang up on either the upswing or downswing - that could be
broken 'ears' on the throwout bearing.
- Stick your fingers under the forward edge of the dash sound
cover just above the brake pedal and feel for wet, and smell
your fingers - odor of brake fluid means the master is leaking.
- Also check for clutch master cylinder flex to one side when
the pedal is depressed - the pedal bracket mounting the
master cylinder fatigues and cracks, allowing the master to
move around. Time-consuming to replace, but not hard.
- If brake fluid is leaking out of the drain hole of the bell
housing, the clutch slave cylinder is leaking - very common,
but cheap and easy to fix. Smell it to distinguish from oil,
but bear in mind that you could be getting both. Another
tip-off for this one is really clean brake fluid, from someone
topping it up as it coats their garage floor. Another
symptom for the slave being bad is that the clutch disengages
very close to the floor, or the pedal will not return.
- While you're down there, check that the rear tranny mounts
have not gone to mush, they do that. Check the engine mounts
too; check for cracks in the top, especially on the right.
- Many of these beasties have developed a lot of play in the
shift mechanism: worn shifter bushings, mushy rubber mounts
on the shift pivot mounting plate. I greatly enjoy the
result of the Metric Mechanic short-shift kit. Stock shifter
bushing parts will cost you $35-$60 at a dealer, MM shifter
$200, ACS shifter $800. Or BL/SS. No affiliation.
end-o-part-2. Larry F.
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