Bulk coolant supply is contaminated
Check the coolant supply. Drain the coolant and replace with non-contaminated coolant. Refer to
Procedure 008-018.
Cylinder head is cracked or porous
Pressure-test the cylinder head. Refer to Procedure 006-013 to disconnect the fuel drain connection at the rear of the cylinder head.
Pressure test the cooling system and look for coolant leaks. See Procedures 008-020 and 002-004.
