GM Service Manual Online
For 1990-2009 cars only

Checks

Causes

Excessive oil consumption (not due to leaks) is the use of 0.95 liters (1.0 qt) or more of engine oil within 2,414 kilometers (1,500 miles).

Preliminary

The causes of excessive oil consumption may include the following conditions:

    • External oil leaks
        Refer to Oil Leak Diagnosis .
    • Incorrect oil level or improper 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.
    • Improper 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 severe usage
    • Crankcase ventilation system restrictions or malfunctioning components
    • Worn valve guides and/or valve stems
        Refer to Cylinder Head Cleaning and Inspection .
    • Worn or improperly installed valve stem oil seals
    • Piston rings broken, worn, not seated properly
        Allow adequate time for the rings to seat.
        Replace worn piston rings as necessary.
    • Piston and rings improperly installed or miss-fitted to the cylinder bore