GM Service Manual Online
For 1990-2009 cars only

Checks

Causes

Above acceptable oil consumption, not due to leaks, is the use of 1 L (1 qt) or more of engine oil within 3200 kilometers (2,000 miles).

Preliminary

The causes of above acceptable oil consumption may include the following conditions:

    • External oil leaks
        Refer to Oil Leak Diagnosis.
    • Incorrect oil level or incorrect reading of the oil level indicator.
        With the vehicle on a level surface, run the engine for a few minutes, allow adequate drain down time, 2 - 3 minutes, and check for the correct engine oil level.
    • Incorrect oil viscosity.
        Refer to the vehicle owners manual and use the recommended SAE grade and viscosity for the prevailing temperatures.
    • Continuous high speed driving and/or extreme usage.
    • Crankcase ventilation system restrictions or malfunctioning components.
    • Worn valve guides and/or valve stems.
    • Worn or incorrectly installed valve stem oil seals.
    • Piston rings broken, worn, or not seated correctly
        Allow adequate time for the rings to seat.
        Replace worn piston rings as necessary.
    • Piston and rings incorrectly installed or not fitted to the cylinder bore.