Zoltan, just wait till you see where those sensors are and how hard they are
to get to.
Do this: find the plug between the brown sensor wires and the wiring
harness. It's a two-connector plug in the vicinity of the thermostat
housing. Take it apart and clean the contacts. Also clean the connections at
the sensors. It's 90 percent likely that your problem will be solved. If
that doesn't do it, replace the sensor by the water pump first. You'll have
to pull back the rear tin.

Jim

On Wed, Jul 23, 2008 at 8:38 AM, Allan Streib <streib@cs.indiana.edu> wrote:

>  "The Westy man" <thewestyman@GMAIL.COM> said:
>
> > OK, I will check the pressure then change the switch if I have to.
> > 140k on engine, compression is very good, engine quiet, smooth.  And it
> only
> > comes on when I push it up to 2300.
>
> There are two separate oil pressure alarms.  One is triggered by the
> sensor on the crankshaft oil journal, on the bottom left side of the
> engine.  It illuminates the oil pressure lamp (but not the buzzer) if
> the pressure falls below 0.3 bar at any time.
>
> The other circuit flashes the lamp and sounds the buzzer if the pressure
> falls below 0.9 bar with the engine above 2000 RPM.  It is located sort
> of under the crank pully, kinda tricky to get at.
>
> It's not unheard of for the wrong sensor to be installed.  My van had
> the buzzer problem after it warmed up; turned out that there was a 1.8
> bar sensor installed instead of the 0.9 bar.
>
> Good luck.
>
> Allan
> --
> 1991 Vanagon GL
>