- Dirt in the engine oil
- Air inlet leaks
- Fuel leakage into engine oil
- Incorrect engine oil
- Incorrect maintenance interval for the application
- Incorrect engine settings
Remove dirty engine oil. Install new filter elements. Put clean oil in the engine. Check the oil filter bypass valve for a weak spring or a broken spring. Look for the source of the contamination.
Inspect the air filter for leaks. Inspect all gaskets and connections. Make repairs if leaks are found.
Fuel Leakage into the Engine Oil
Fuel leakage into the engine oil will cause high fuel consumption and low engine oil pressure. This condition may also increase the oil level in the crankcase. Make repairs if leaks are found. Install new parts, as required.
Check oil recommendations for the proper oil specifications for the engine operating conditions.
Incorrect Maintenance Interval
Review the oil change intervals in relation to the nature and severity of the engine application. Review the records for the engine in order to verify that the recommended intervals are being followed.
Check the following items for proper adjustment:
- Timing
- Unit injector synchronization
- Fuel setting
- Valve lash
Refer to System Operation, Testing and Adjusting for more information.