GM Service Manual Online
For 1990-2009 cars only

An engine that has excessive oil consumption uses 0.9L (1 qt) of oil, or more, within 2,000 miles (3200 km). The following conditions are indications of excessive oil consumption:

    • Improperly read oil level indicator (dipstick)
       - Check the oil while the car is standing on a level surface.
       - Allow adequate drain-down time.
    • Improper oil viscosity
       - Use the recommended SAE viscosity for prevailing temperatures.
       - Refer to Maintenance and Lubrication for the proper oil viscosity specifications.
    • Continuous high-speed driving
    • Severe hauling, such as a trailer, causing decreased oil mileage
    • Malfunctioning crankcase ventilation system
    • External oil leaks
       - Tighten the bolts, as necessary.
       - Replace the gaskets and seals, as necessary.
    • Worn or omitted valve guides and/or valve stem seals
        1. Ream the guides.
        2. Install oversized service valves and/or new valve stem seals.
    • Broken, improperly installed, worn or unseated piston rings
    • Piston improperly installed or improperly fitted
    • Plugged oil drain holes in the cylinder head and/or cylinder head gasket.