Dash Warning Lights: Oil (Engine) Light

Most vehicles are equipped with several dash warning lights often called “telltale” or “idiot” lights. These lights are often the only warning a driver receives that there may be engine problems.

- Oil (Engine) Light
- Coolant Temperature Light

The red oil light indicates that the engine oil pressure is too low (usually lights when oil pressure is 4 to 7 PSI [20 to 50 kPa]). Normal oil pressure should be 10 to 60 PSI (70 to 400 kPa) or 10 PSI per 1000 engine RPM. When this light comes on, the driver should shut off the engine immediately and check the oil level and condition for possible dilution with gasoline caused by a fuel system fault. If the oil level is okay, then there is a possible serious engine problem or a possible
defective oil pressure sending (sender) unit. The automotive technician should always check the oil pressure using a reliable mechanical oil pressure gauge if low oil pressure is suspected.

Some automobile manufacturers combine the dash warning lights for oil pressure and coolant temperature into one light, usually labeled “engine.” Therefore, when the engine light comes on, the technician should check for possible coolant temperature and/or oil pressure problems.