<E28> Purchase/Maintenance Observations, Part 2 of 3

[Pearson-Franks Family <pearsonf@xxxxxxxxxxx>]

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
      potential problems.
    - 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@domain.elided> 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.

Larry Franks
Issaquah, Washington
'86 535i x 2
'83 245 GLT (Swedish iron)

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