97 A4 1.8 oil sensor dying?

Oil pressure switches do fail on occasion.

Looking at the Bentley CD covering the '97 A4 1.8 turbo: On your model, the oil pressure switch is located on the "Oil Filter Bracket" - which is located on the driver's side of the engine, and roughly in the middle of the side of the engine block.

If you can find the oil filter, it hangs just below the oil cooler, which snugs up to the Oil Filter Bracket. The switch is screwed into the bracket towards the rear. Don't confuse the pressure switch with the oil temperature sensor, which is also screwed into the same bracket, but more to the side of the bracket. ie: the switch is more towards the rear of the car than the temperature sensor.

I stuck a copy of the pertinent manual pages here:

/daytripper '00 s4 6spd

Sweet!

Many thanks.

If your oil pressure switch is bad then changing it is very simple, like daytripper says. If that does not solve our problem then check the oil pressure with a mechanical gauge. If the oil pressure is low then it might be sludge or maybe a bad oil pump. I think that the early oil pumps got upgraded. It is a good day (read a lot of work) to change out the oil pump if you need one. If you have to clean out the sludge and you have to remove the oil pan then change out that oil pump too! ;-)

BTW which oil and oil filter are you using?