Oil Light

The oil light came on in my 98 chevrolet cavalier 2.2 yesterday as i went to the gas station. i put a couple of quarts of 5w-30 in it. when i started the car it was off but came on 2 minutes later. i assumed it didn't have enough off time to reset so i got home and let it sit. a few hours later i checked the level and it was good so off i went to work in it. 10 minutes later on the highway, it came on again. since i had to get to work and i knew the level was fine, i kept going. i hadn't had an oil change in some time so i hoped that would fix it. i went to an oil change place and got the change (they put 10w30). during my drive home (60 miles), it never came back on. now, today, it has come back on. assuming the oil level is fine, what should i check? the car has approx 183,000 miles on it.

thank you

The oil light comes on because of lack of pressure not because its low. In theory an oil pressure gauge should be used to to check actual oil pressure. It's not terrible expensive or difficult to replace the oil pressure sending unit which could be the problem.

The oil light comes on because of lack of pressure not because its low. In theory an oil pressure gauge should be used to to check actual oil pressure. It's not terrible expensive or difficult to replace the oil pressure sending unit which could be the problem.

that's what i figured but i also though that if the level was low, the pressure would be low which would trigger the light. i had her come and switch cars with me and when i drove it, the light didn't come on.

The light would come on as you where just about to run completely out of oil. Since there wouldn't be enough left in the oil pan to get pumped through the engine and even then it would be because of the lack of pressure rather than the lack of oil.

I would agree the problem is likely the sending unit (pretty common), or you have a bad oil pump (less common). If you find the sending unit is bad, I'd suggest you change the oil to the correct viscosity, which is probably 5W-30, as well.

-Rod