GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2009 🢒 Isuzu - N Series 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L 🢒 Oil Consumption Diagnosis

Checks

Causes

Excessive oil consumption, not due to leaks, is the use of 1 L (1 qt) or more of engine oil within 3 200 kilometers (2,000 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 measure 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
        Refer to Crankcase Ventilation System Inspection/Diagnosis.
    • Worn valve guides and/or valve stems
    • Worn or improperly installed valve stem oil seals
        Refer to Spark Plug Inspection.
    • Piston rings broken, worn, or not seated properly
        Allow adequate time for the rings to seat.
        Replace worn piston rings, as necessary.
        Refer to Cylinder Leakage Test.
    • Piston and rings improperly installed or not fitted to the cylinder bore