GM Service Manual Online
For 1990-2009 cars only

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.

  1. A slower than normal cranking speed may indicate coolant entering the combustion chamber. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate .
  2. Remove the spark plugs and inspect for spark plugs saturated by coolant or coolant in the cylinder bore.
  3. Inspect by performing a Cylinder Leakage Test . During this test, excessive air bubbles within the coolant may indicate a faulty gasket or damaged component.
  4. 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 Side and/or Cylinder Head Replacement - Right Side .

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 .

Cracked cylinder head

Replace the cylinder head and gasket. Refer to Cylinder Head Replacement - Left Side and/or Cylinder Head Replacement - Right Side .

Cracked cylinder liner or engine block

Replace the engine. Refer to Engine Replacement .

Cylinder head or engine block porosity

Replace the cylinder head(s) or engine. Refer to Cylinder Head Replacement - Left Side and/or Cylinder Head Replacement - Right Side or Engine Replacement .

Leaking supercharger cooling system

Inspect charge air cooler components. Refer to Charge Air Cooler Cooling Tube Replacement , Charge Air Cooler Housing Replacement or Supercharger Replacement and Supercharger Cleaning and Inspection . Replace components as required.