Oil Consumption Diagnosis
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Oil Consumption Diagnosis
| Checks |
Causes |
| 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
- 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 improperly fit to the cylinder bore
- Turbocharger oil leaks - Inspect the turbocharger exhaust outlet and the turbocharger air inlet duct for excessive oil residue. Excessive oil may indicate a restricted oil drain pipe or worn turbocharger bushings/seals. If turbocharger wear is at fault, inspect for continuous oil flow from the turbocharger oil feed line. Restricted oil flow may indicate a blocked oil feed line, blocked oil passage in the engine block, or a spun camshaft bearing.
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