Identify lubricating oil contamination
Perform an oil analysis to determine the contaminants.
Fuel in the lubricating oil
Refer to the Fuel in the Lubricating Oil symptom tree
Internal coolant leaks
Refer to the Coolant Loss -Internal symptom tree.
Lubricating oil sludge is excessive
Change the oil and filters. Refer to Procedure 007-037 and the Lubricating Oil Sludge in the Crankcase Excessive symptom tree.
Bulk oil supply is contaminated
Check the bulk oil supply. Drain the oil and replace with noncontaminated oil. Replace the oil filters. Refer to Procedures 007-013 and 007-037.