<E28> Purchase/Maintenance Observations, Part 1 of 3

[Pearson-Franks Family <pearsonf@xxxxxxxxxxx>]

Fellow Digesters:

The following notes are a collection of observations and
experiences with my fav Bimmers:  older 5ers.  My observations
are just that, not necessarily the Truth (capital 'T'),
but _my_ experiences and judgements, leavened with mucho experience
from other Digesters.  My thanks to Mssrs Anderson, Boylan, D'G,
Eilenberger, Levinson, Lin, Stock, Tangen and of course, Welty,
without whom this would all be impossible. Or at least harder!

I included wildly personal prices where I could, for ballpark
info and potential purchase price negotiation.  I look at them
from the point of view of the DIYer, parts plus shop time (if required).

Comments, corrections, additions all welcome.  With any luck
at all, this will be useful to others who enjoy these cars as
much as I do!

I grouped the the classic E28 look-for's:

1)  Head, cam & engine
2)  Cooling system
3)  Oil (& oil leaks!)
4)  Other engine compartment stuff
5)  Tranny and clutch
6)  Driveline
7)  Suspension, steering and brakes
8)  Interior, Electrical
9)  General (catch-all)

1)  Head Gasket and other Engine Notes:
    - Top end work a frequent 100,000ish requirement.  $1500+ for
      parts (do all belts and hoses, too!) and shop time.
    - Compression or leak-down test very informative, look for
      160+ on all cylinders, +/- 5 OK, +/- 10 marginal.  If you
      want details on my many recorded numbers, or a rap on the
      leakdown test, drop me a note.
    - If you pull the valve cover (which I would recommend) check
      that the two 12mm head 'banjo bolts' that secure the oil
      bar to the head are snug.  If these are loose this is _bad_
      (refer to definition above).  There is a new variety with a
      thread-locking feature, distinguished by a circle on the top.
      (somebody might drop me the correct part number - I thought
       I had it, but my local dealer sneezed on hearing it).
    - Check the cam rubbing surfaces:  the peaks of the cam lobes
      should have no discernable wear (using the patented fingernail
      technique) and the rubbing blocks on the underside of the
      rocker arms should all appear the same in profile.  If the
      banjo bolts were loose, TAKE YOUR TIME doing this part!
      If replacing the cam, add $300 to head job.
    - Easy things to look for in this department:  coolant.  If
      someone is concealing a known head gasket problem, the coolant
      may be clear and/or rusty, meaning they consume a lot, and have
      been just adding water, or the coolant may be suspiciously
      clean, meaning added to all the time.
    - Spark plug condition.  In addition to the normal interpretation
      found in every Haynes manual (the color picture page), look for
      differences in plug color.  Cylinders leaking coolant will have
      _very_ clean plugs.  Pressure washed, if you will.
    - Coolant burners (cracked head or bad head gasket) will put out
      reams of white smoke (actually steam) when they are first
      warming up.  Smells kinda sweet, not unlike coolant.
    - Coolant system pressure and leak-down useful, but not definitive
      for head leak problems.  Cracks, or high porousity areas may
      not show up with a static pressure test.
    - If you are looking at an 'e' motor and do not have conclusive
      proof that the timing belt has been replaced in the last 5 years
      or 50,000 miles, just do it.  Better than bent valves, etc.!

2)  Cooling System
    - It's my experience that radiators are a 8 - 10 year
      consumeable.  The E12's have brass cores and tanks and can be
      rodded out.  The E28's have aluminum cores with plastic tanks
      clipped to them with one-time-use crimps.  And, the plastic ages
      badly, leading to broken hose connections, etc.  Not worth
      repairing IMHO, but some Digesters have had good luck with
      Reseda Radiator.
    - Normal water pump inspection:  check the water pump by rocking
      the fan, both in line and 90 degrees from the pressure of the
      belts.  Play should be small, and the same in each direction.
      $45 part, add $200 for all belts and hoses.
    - From underneath with a light, find the 'weep-hole' just aft
      of the fan clutch mount.  Should have no 'tear-tracks'
      left from a bad bearing seal.
    - Belts and hoses should be uncracked and not bulgy, respectively.
    - Temp guage should run at 10:30 to 12 o'clock under any and
      all conditions.  After a test drive, leave it idling for 15
      minutes or so and see what it goes up to and settles at.
      Anything over 12 o'clock means maintenance coming up.
      Radiator likely, typical consumable.  $240 part.
    - If suspicious of guage/sensor inaccuracy, wrap your hand around
      the upper radiator hose:  if you can squeeze it for an
      indefinite amount of time, <50 C, not warmed up yet.  Hold
      several seconds, 70 - 90 C, OK.  Can't hold 1 second, >90 C,
      which means trouble.  Or, use a candy thermometer.  But hey,
      you probably had your hands in your pockets and NOT a thermometer!
    - Check fan clutch.  Should not freewheel when spun, but have a
      certain resistance.  Should give more resistance at temp, but
      this is hard to 'feel', in my experience.  $30ish.
    - Heater control solenoid fails, resulting in erratic heat, or
      heat all the time.  Easy fixes, write for details.  $25 for kit
      which replaces innards.

End-o-part-1.  Larry F.

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

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