John Smith wrote:
>
> The warning starts (and usually stops soon after) from as soon as a minute
> or two after the engine has been started or as late as more than an hour or
> so. This can occur several times over a short journey. It has been happening
> for a year or so now. Warning doesn't show before the car is started
>
> Didn't know about the two sensors - I'll check that out.
>
> My model has an oil pressure gauge as well as an oil temp gauge. The
> pressure showas as around 4 bar at all times - towards the top end of the
> gauge. Oil temp is OK and oil level is always OK
>
> I guess I've been treating it as an electrical/computer fault so far but

On the dynamic oil pressure warning system there is a small electronic
gizmo that selects between the output from the two oil pressure sensors
depending on the engine RPM. It was not uncommon for this gizmo to fail,
causing the oil pressure warning light / buzzer to come on even though
the oil pressure was fine. This electronic gizmo was built into the
tachometer on late 80's VW Golfs / Jettas, don't know if the '92 100 was
similar.

 

John Smith wrote:
>
> The warning starts (and usually stops soon after) from as soon as a minute
> or two after the engine has been started or as late as more than an hour or
> so. This can occur several times over a short journey. It has been happening
> for a year or so now. Warning doesn't show before the car is started
>
> Didn't know about the two sensors - I'll check that out.
>
> My model has an oil pressure gauge as well as an oil temp gauge. The
> pressure showas as around 4 bar at all times - towards the top end of the
> gauge. Oil temp is OK and oil level is always OK
>
> I guess I've been treating it as an electrical/computer fault so far but

On the dynamic oil pressure warning system there is a small electronic
gizmo that selects between the output from the two oil pressure sensors
depending on the engine RPM. It was not uncommon for this gizmo to fail,
causing the oil pressure warning light / buzzer to come on even though
the oil pressure was fine. This electronic gizmo was built into the
tachometer on late 80's VW Golfs / Jettas, don't know if the '92 100 was
similar.

 

John Smith wrote:
>
> The warning starts (and usually stops soon after) from as soon as a minute
> or two after the engine has been started or as late as more than an hour or
> so. This can occur several times over a short journey. It has been happening
> for a year or so now. Warning doesn't show before the car is started
>
> Didn't know about the two sensors - I'll check that out.
>
> My model has an oil pressure gauge as well as an oil temp gauge. The
> pressure showas as around 4 bar at all times - towards the top end of the
> gauge. Oil temp is OK and oil level is always OK
>
> I guess I've been treating it as an electrical/computer fault so far but

On the dynamic oil pressure warning system there is a small electronic
gizmo that selects between the output from the two oil pressure sensors
depending on the engine RPM. It was not uncommon for this gizmo to fail,
causing the oil pressure warning light / buzzer to come on even though
the oil pressure was fine. This electronic gizmo was built into the
tachometer on late 80's VW Golfs / Jettas, don't know if the '92 100 was
similar.