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 cylinder block cooling system passages. Refer to Diagnostic Starting Point - Engine Cooling.

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 cylinder block for damage to the coolant passages and/or a faulty head gasket.
    â€¢ Repair or replace as required.