Coolant in Combustion Chamber

WARNING: This page is about a different car, the 2006 GMC Yukon XL, 2006 Chevrolet Suburban, and 2006 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

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 leak-down test. During this test, excessive air bubbles within the coolant may indicate a faulty gasket or damaged component. Refer to Cylinder Leakage Test . 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 - Left or Cylinder Head Replacement - Right .
Cracked cylinder head	Replace the cylinder head and gasket.
Improper sealing of exhaust valve guide-to-cylinder head	Replace the cylinder head and gasket.
Cracked engine block	Replace the components as required.
Cylinder head or engine block porosity	Replace the components as required.
Warped cylinder head	Machine the cylinder head to the proper flatness, if applicable and replace the cylinder head gasket. Refer to Cylinder Head Cleaning and Inspection .
Defective external oil cooler	Replace the components as required.