oil light goes on and off. what could it be?

Either you are very low on oil (check the oil level first). The oil pressure sending unit might be bad. There could also be a problem with the dash cluster, or wiring. Get it checked-out by a local mechanic! (Not yelling at you, just very important). A loss of oil pressure can cost you thousands of dollars in engine repairs. A tow to a local shop is cheaper. Being down 1 quart of oil usually doesn't trigger the oil light.

The oil filter is installed horizonally, thus the oil filter will tend to not remain full at all times and will cause light to go on and off. The remedy is to buy and oil filter that has two valves in it, a bypass valve and a one way valve that causes the filter to stay full at all times. I installed a Fram XG 2 that has 2 valves in it and light has remained off up to this point. Filter is a little more expensive.

The oil filter is installed horizonally, thus the filter doesn't remain full at all times causing the light to go on and off...Use a high quality filter with 2 valves in it, a bypass valve and a one way valve to keep the oil filter full at all times. I installed a Fram XG 2 filter with 2 valves in it and the light has remained off to this point. Filter is a little more expensive.

Some problems with with lights not going out or ect. can be remedied by disconnecting battery terminal for 5 minutes then re- connect. Its like letting the vehicles computer reset everything by rebooting.

Gasket between oil filter housing and block had a very small leak at times causing the oil sensor not to receive full oil pressure for accurate reading , thus the light stayed on for up to 8 minutes before going out after warming up good...replaced the gasket and oil sensor and corrected the problem...oil light now goes off within 3-5 seconds.