Oil is as important to your car's engine as blood is to your body. The engine oil lubricates, cools and cleans the engine. The oil light will go on for only two reasons: either the oil is low or the oil pump has stopped pumping. In both cases, the consequences are expensive if you keep driving. An engine without oil will "seize up," requiring a complete overhaul or a new engine.
If the oil light goes on, pull over as quickly and safely as you can.
Turn off the engine.
Put on your hazard lights and open the hood.
Check the oil (see "How to Check Your Car's Engine Oil" under Related eHows).
Add oil if it is low. Restart the engine and check the light.
It is OK to drive if the light is now off.
Check the oil again in a few hours and over the next few days. If it is consistently low, there is a leak. See your mechanic.
