oil pressure light

[bsharbonda]

Please help, My oil pressure light stays on all the time. I am getting oil pressure and have changed the oil pressure sending unit. What can I do to fix this? I have a 1988 Audi 80 with 177,000 miles on it.

[scotty33]

Hi

First thing is to make sure there is the correct amount of oil and that it is not old oil that has gone out of grade.
If you are happy with the oil, there are two pressure switches that can bring on the buzzer/oil light.
One operates from idle, it will alarm, if the pressure is not above approx 0.8 bar.
The second switch will operate if the oil pressure is not above approx 2 bar at approx 2500 rpm. I forget the exact figures, but in the ballpark?
So is your light coming on at low rpm's or above 2500?
Which engine do you have? 2.3 5 cyl = NG?
What colour was the plastic part on the switch you changed?

If you are happy both switches are working as they should, then you either have an oil problem (maybe try thicker oil), or something like a blocked oil pick-up pipe in the sump/worn big end bearings.