Coolant has entered the engine oil

Definition: Foamy or discolored oil, or an overfilled engine may indicate coolant has entered the crankcase. Low coolant levels, an inefficient cooling fan, or a faulty thermostat can lead to conditions "excessive temperature", which may cause damage to engine components. Dirty engine oil and dirty oil filter must be replaced.

Cause	elimination
Check the oil for excessive foaming or check for excessive oil filling in the engine. Oil diluted with coolant may not effectively lubricate the main bearings, resulting in engine component damage. See Noise at the bottom of the engine regardless of engine speed. Check by testing the cylinder for leaks. During this test, excessive air bubbles in the cooling system may indicate a gasket failure or component damage. Inspection should be carried out when checking the degree of compression in the cylinder. The presence of a low compression ratio in two adjacent cylinders of an engine block may indicate a failure of the cylinder head gasket. See "Compression pressure test"in this section.
Cylinder head gasket defective.	If necessary, replace the gasket and cylinder head components. See Section 1C1, Engine Mechanical - FAM II 2.4D.
Deformed cylinder head.	Machine the cylinder head to the correct flatness, if possible, and replace the cylinder head gasket. See Section 1C1, Engine Mechanical - FAM II 2.4D.
The cylinder head cracked.	Replace cylinder head and gasket.
Cracked cylinder liner or engine block.	If necessary, replace these engine components.
There is porosity in the cylinder head or cylinder block.	If necessary, replace these engine components.