GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Low oil pressure

    â€¢ Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing .
    â€¢ Repair or replace damaged components as required.

Improper lubrication of the valve train components

    â€¢ Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing .
    â€¢ Inspect the valve rocker arms.
    â€¢ Inspect the valve push rods.
    â€¢ Inspect the valve lifters.
    â€¢ Inspect the oil filter bypass valve.
    â€¢ Inspect the oil pump and pump screen.
    â€¢ Inspect the engine block oil galleries.
    â€¢ Repair or replace damaged components as required.

Worn, damaged or improperly installed valve rocker arm

    â€¢ Inspect the valve rocker arms.
    â€¢ Repair or replace damaged components as required.

Worn or damaged valve rotator

    â€¢ Inspect the valve rotators.
    â€¢ Repair or replace damaged components as required.

Broken valve spring

    â€¢ Inspect the valve springs.
    â€¢ Repair or replace damaged components as required.

Worn, damaged or stuck valves, carbon on the valve stem or valve seat

    â€¢ Inspect the valves.
    â€¢ Inspect the valve guides.
    â€¢ Repair or replace damaged components as required.

Worn or damaged valve guide

    â€¢ Inspect the valve guides.
    â€¢ Inspect the valves.
    â€¢ Repair or replace damaged components as required.

Worn, damaged or bent valve push rod

    â€¢ Inspect the valve rocker arms.
    â€¢ Inspect the valve push rods.
    â€¢ Inspect the valve lifters.
    â€¢ Repair or replace damaged components as required.

Worn, damaged or dirty valve lifter

    â€¢ Inspect the valve lifters.
    â€¢ Repair or replace damaged components as required.

Worn or damaged camshaft lobes

    â€¢ Inspect the engine camshaft lobes.
    â€¢ Repair or replace damaged components as required.

Worn, damaged, improperly installed or loose timing chain and sprockets

    â€¢ Inspect the timing chain and sprockets.
    â€¢ Repair or replace damaged components as required.

Worn, damaged or improperly installed timing chain tensioner, if equipped

    â€¢ Inspect the timing chain tensioner.
    â€¢ Repair or replace damaged components as required.