GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Faulty cylinder head gaskets and/or cracking or other damage to the cylinder heads and engine block cooling system passages

Coolant consumption may or may not cause the engine to overheat.

    â€¢ Inspect for spark plugs saturated by coolant. Refer to Spark Plug Inspection .
    â€¢ Perform a cylinder leak down test. Refer to Cylinder Leakage Test .
    â€¢ Inspect the cylinder heads and engine block for damage to the coolant passages and/or a faulty head gasket. Refer to Coolant in Combustion Chamber .
    â€¢ Repair or replace, as required.