Manual:HUMMER Hummer H3 Base 2010Page:10130 / 37523



Coolant in Combustion Chamber — 2010 Hummer H3 Base, Automatic Service Manual

Coolant in Combustion Chamber

Cause Correction
DEFINITION: Excessive white smoke and/or coolant type odor coming from the exhaust pipe may indicate coolant in the combustion chamber. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an "overtemperature" condition which may cause engine component damage.
  • A slower than normal cranking speed may indicate coolant entering the combustion chamber. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate .
  • Remove the spark plugs and inspect for spark plugs saturated by coolant or coolant in the cylinder bore.
  • Inspect by performing a Cylinder Leakage Test . During this test, excessive air bubbles within the coolant may indicate a faulty gasket or damaged component.
  • Inspect by performing a cylinder compression test. Two cylinders "side-by-side" on the engine block, with low compression, may indicate a failed cylinder head gasket. Refer to Engine Compression Test .
Faulty cylinder head gasket Replace the head gasket and components as required. Refer to Cylinder Head Cleaning and Inspection and Cylinder Head Replacement .
Warped cylinder head Replace the cylinder head and gasket. Refer to Cylinder Head Replacement .
Cracked cylinder head Replace the cylinder head and gasket.
Cracked cylinder sleeve or engine block Replace the components as required.
Cylinder head or engine block porosity Replace the components as required.