1992 Corolla Oil Light - Pre-1997 Toyota Corolla and Geo Prizm

Guest HoosierDadIndy

My daughter told me that the oil light on her 1992 Corolla with 94K miles on it is coming on. It comes on after the engine is warm (6-7 miles) and only comes on when she pulls up to a stop.

I drove it to work today and the symptoms are:

Oil Light comes on only after engine is warm does not come on after starting cold

RPMs drop down below approximately 900rpm

I can rev the engine in neutral back above 1000rpm and the light goes back out

Oil & filter changes 3 weeks ago. Oil level is perfect.

Engine leaks but I keep the oil level where it should be

Any ideas if I have a pressure unit going out or does it sound like the oil pump is on it's way out?

Thanks,

HoosierDadIndy

Could be the sending unit going bad - doubt it would be the oil pump, but anything is possible. Best way is to wiring in a "real" oil pressure guage and monitor oil pressure at cold start, idle, under operation, etc. Bad crankshaft bearings can also cause poor oil pressure or pressure that fluctuates - but from your description - sounds more like the sending unit is bad or has a band ground/sensor connection to the gauge cluster.

Welcome to the forum!

The light is going on when the pressure is dropping. I agree with Fishexpo's comments, however you might also want to check your oil. If it is very low viscosity, it could cause the light to go on. Smell the dipstick - does it smell of gasoline?

Also, check to see if they used the correct viscosity oil. They should have used 5W30. If they used 5W-20, and your engine is a little worn, it may be causing your symptoms. If so, I suggest that you top off your oil with something like a 10W40 or 10W50 and see if the problem goes away. But don't overfill.

Bikeman982

I had a 1992 that used to do the same thing. The light would come on when I let it idle and when it was in Park. I wanted to make sure everything was good, so I changed the oil and filter and also did a complete tune-up on it. It was the low idle that made the light come on. After the tune-up it idled just a little faster and the light worked as designed. Hope this helped.