Re: 5K - engine warning system

[Robert Houk - SMCC WorkGroup Server Firmware <Robert.Houk@East.Sun.COM>]

   I have an 88 100CD (5000) with a low oil pressure warning light that
   keeps coming on. There is nothing wrong with the engine, no oil leaks,
   no oil consumption (only done 90,000 miles). The oil pressure senders
   have been replaced. Oil and filter change has been done. Anybody got
   any ideas on:

   1. What the spurios low oil pressure signal is (only comes on at 3000
   RPM),
   2. If no anwers to 1, how to disconnect the engine warning system.

You can't really say "nothing wrong" without more data; specifically
an accurate oil pressure *gauge* (and I specifically exclude most
little dash gauges!).

At least some Audii use a multiple-stage OilPressureIdiotLight -- some
minimum pressure at "idle", and another reasonable pressure at "speed"
(e.g., 3000rpm!).

This means you've got some GermanElectricGizmo involved in the system.
Further, this implies that you have a Gizillion GermanElectricCrimp
connectors all together in series . . . be afraid . . . be very
afraid!

First, verify mechanically ("gauge") that the oil pressure warning
system is in fact malfunctioning (replacing the senders means only
slightly more than nothing! -- you might really have low pressure!),
then dive into the wiring and check out the gizmos.

Good Luck!

					-RDH

P.S.	90,000 miles is *easily* long enough to have lunched a bearing,
	worn out the oil pump, etc, and so forth, "enough" to be running
	just enough low (pressure) at 3000rpm...you could have an ob-
	struction in the oil gallery that is blocking oil flow and causing
	low pressure at high flow rates (3000rpm). The pressure relief
	spring in the oil pump could be weak after 10 years. There are
	a *LOT* of ways your oil pressure could be lower than desired.
	Make very VERY sure this is not the case before disconnecting
	the oil warning system!