ALT-7 What to do when your Oil Light comes on
When your oil light comes on it means, Whoa! Actually, it depends on when it comes on. Oil lights always light up when you start your car for a few seconds for a lamp test. You should always pay attention to this because if any of your warning lights fail to light up, you need to have it fixed. If you don't, and the problem that it is supposed to warn you about really happens, you will drive the car ignorantly until something worse happens.
If it comes on immediately after you have just changed your oil and filter on the first start up, give it a few seconds because your system has to refill with oil. Your filter is empty, and it takes a moment for it to get up to the correct pressure. Most cars have the oil pressure sending unit affixed where the filter attaches.
If your light stays on at this point, shut your car off and look for leaks. The two place that are most likely guilty are the drain plug and the oil filter. If there are no leaks, check your oil level. You or someone else may have forgotten to refill your car with oil after it was drained.
If you have oil and your dip stick shows that you are significantly overfilled, let your car set a minute or two and try again. Sometimes old sediment can get stirred up and cover the screen near your oil pump. If you start it again and the light stays on, listen to your engine if you can hear the lifters clacking, turn your car off and have it towed to a mechanic. Or, if you prefer, pull your oil pan and replace your oil pump yourself. If the lifters are quiet, you probably need to replace your oil pressure sending unit.
If you are driving down the highway and your oil light suddenly just lights up, pull to the shoulder. Listen for a second to your engine and then shut it off. Check your oil. If it is low and you have oil, fill it up. If it is either not low or you don't have oil, what did your engine sound like just before you shut it off? If your lifters were clacking, give it a minute or two and restart your engine. If it sounds quiet, drive to the nearest mechanic and have it checked out and/or refilled with oil if you were low.
If your lifters are still noisy, and you were low on oil, drive directly to the nearest exit and buy oil. If you are many miles from an exit, I would call for help. You could destroy your engine if you drive too far without enough oil pressure to fill your lifters. If your lifters were still noisy, and you weren't low on oil, call for help, or you will do damage to your engine.
If your oil light comes on when you suddenly reduce speed like at a stop light or exiting a highway, you are probably low on oil. Your light will usually come on for a few seconds at these times and go back out. This is because you are too low on oil to keep your pump filled when the oil in your pan pours forward from you slowing down. Drive to the nearest place to buy oil and refill your engine.
