>Topic No. 36

-Date: Tue, 31 Oct 1995 10:20:08 -0500 (EST)
-From: nyquist@ubvms.cc.buffalo.edu (John Nyquist)
-To: vanagon@lenti
-Message-ID: <v01510100acbbb4def7c4@[128.205.190.7]>

-Does anyone have a clue to the following?
-I just got my '91 GL back from it's 90k service and took off to visit some
-friends in Michigan.  During the 6 hour drive, in the rain, about every
-other time I would slow down from highway speed (65mph) to make a curve on
-an exit ramp or come to a stop the oil light and buzzer would come on.
-When the weather dried up so did the problem.
-This has happened for years on my '83 diesel Rabbit and I always thought it
-was corroded wires or something because I had leaking around a replacement
-windshield into the dash.  The problem on the Vanagon is a new one for me.
-Any thoughts?

I might.  I had an '85 Jetta with this Dynamic Oil Pressure Warning System
(I believe it is the same system  that is in '86 and later Vanagons).  After
every oil change, I made a habit of degreasing the engine with that spray
"Gunk" stuff and then rinsing.  A couple of times after going through this
procedure, the DOP light and buzzer would go off during driving (always
above 2,500 RPM).

I passed this off to a water-induced short at one of the connectors to one
of the oil pressure switches.  That may have had something to do with it but
the real problem I think had more to do with the fact that when I rinsed the
engine, the oil pressure switches were warm (or maybe hot) because oil was
pouring out of the one mounted on the oil filter flange.  Rinsing a hot
engine with cold water was "cracking" whatever seal between the plastic and
the metal of the switch.  What I don't know is if the oil was causing the
short, or a false low pressure oil reading due to a leak at the switch--oil
shouldn't conduct electricity well, so it was probably the leak.  BTW, my
1992 Passat has rubber covers over the oil pressure switches and connectors
which would protect them from this sort of thing.

The DOP system itself was initially troublesome for VW, lots of replacements
according to my service advisor at the time I had the Jetta.  Another
attempt by VW to fix an early problem with a complicated, less reliable
solution.

Donald Baxter

_________________________________________________________________
Donald Baxter  dab1@jhk.com
JHK & Associates  Norcross, Georgia  404 447-6831  404 449-7268 (FAX)
Not speaking for JHK or SAIC, so react accordingly