GM Service Manual Online
For 1990-2009 cars only
    • Low oil level. Fill to full mark on oil level indicator.
    • Slow idle speed.
    • Incorrect or malfunctioning oil pressure switch.
    • Incorrect or malfunctioning oil pressure indicator.
    • Improper oil viscosity or diluted oil.
         Install oil of the proper viscosity for expected temperature. Install new oil if diluted with moisture or unburned fuel mixture.
    • Oil pump worn or dirty.
    • Plugged oil filter.
    • Oil pickup screen loose or plugged.
    • Hole in oil pick up tube.
    • Excessive bearing clearance. Replace as necessary.
    • Cracked, porous or restricted oil galleries. Repair or replace block.
    • Gallery plugs missing or misinstalled. Install plugs or repair as necessary.
    • Malfunctioning oil pump pressure regulator valve.
    • Camshaft worn or poorly machined. Replace the camshaft.
    • Worn valve guides.