GM Service Manual Online
For 1990-2009 cars only

Low or No Oil Pressure

The following can cause low or no oil pressure:

    • Low oil level -- fill to the full mark on the oil level indicator.
    • Slow idle speed
    • Incorrect or malfunctioning oil pressure switch -- replace the oil pressure switch.
    • Incorrect or malfunctioning oil pressure gage -- replace the oil pressure gage.
    • Improper oil viscosity or diluted oil
       - Install oil of proper viscosity for expected temperature.
       - Install new oil if it is diluted.
    • The oil pump is worn or dirty -- clean or replace the oil pump.
    • The oil filter is plugged -- replace the oil filter.
    • The oil pickup screen is loose or plugged -- replace the oil pickup screen.
    • A hole in the oil pickup tube -- replace the oil pickup tube.
    • Excessive bearing clearance -- replace the bearings.
    • Cracked, porous, or plugged oil galleries -- repair or replace the engine block.
    • The gallery plugs are missing or improperly installed -- install or repair as necessary.
    • The pressure regulator valve is stuck.
       - Check the pressure regulator valve for sticking in the bore.
       - Check the bore for scoring and burrs.
    • The camshaft is worn or poorly machined -- replace the camshaft.
    • Worn valve guides -- repair as needed.