GM Service Manual Online
For 1990-2009 cars only

Checks

Causes

DEFINITION: Oil consumption (not due to leaks) above acceptable tolerances is the use of 1.9 L (2 qts) or more of engine oil within 3 200 km (2,000 mi).

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

Preliminary

    â€¢ External oil leaks - Refer to Oil Leak Diagnosis.
    â€¢ Incorrect oil level or incorrect reading of the oil level indicator.
        Position 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.
    â€¢ Incorrect oil viscosity.
        Refer to the vehicle owners manual and use the recommended SAE grade and viscosity for the prevailing temperatures.
    â€¢ Continuous high speed driving and/or extreme usage.
    â€¢ Crankcase ventilation system restrictions or malfunctioning components.
    â€¢ Worn valve guides and/or valve stems.
    â€¢ Worn, missing or incorrectly installed valve stem oil seals.
    â€¢ Piston rings not seated correctly.
        Allow adequate time for the rings to seat.
    â€¢ Piston rings broken or worn
    â€¢ Piston and rings incorrectly installed or miss-fitted to the cylinder bore