GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Low oil pressure

    • Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .
    • Repair or replace as required.

Broken valve spring

Replace the valve spring.

Worn and/or damaged valve rotators

Replace the valve rotators as required.

Worn or dirty valve lifters

Replace the valve lifters.

Stretched or broken timing chain and/or damaged sprocket teeth

Set or replace the timing chain and sprockets.

Worn or improperly set timing chain tensioner, if applicable

Replace the timing chain tensioners as required.

Worn engine camshaft lobes

    • Inspect the engine camshaft lobes.
    • Replace the camshaft and valve lifters as required.

Worn valve guides or valve stems

Inspect the following components, and repair as required:

    • The valves
    • The valve guides

Stuck valves

Carbon on the valve stem or valve seat may cause the valve to stay open.

Inspect the following components, and repair as required:

    • The valves
    • The valve guides