Definition: Fuel Dilution of the engine oil due to fuel leaks under
the valve cover area. In severe cases, fuel/oil leakage may be seen from the
PCV system vent hose and engine roughness or vibration may occur. If fuel
is suspected of leaking into the crankcase, the following procedure should
be performed to verify the condition.
- Remove the oil level indicator and allow oil to drop onto a clean
white paper towel.
- If the oil is diluted with fuel, it will become apparent as the
towel wicks the fuel away from the drop of oil on the towel. The fuel will
expand out in a ring around the oil droplet.
- If fuel dilution is apparent, refer to
Fuel Leak Diagnosis
in engine controls, for diagnosis and repair. After repairs are completed,
perform the test again to verify the condition is corrected.
- If no fuel dilution is present, verify the oil level and correct
as needed.