For 1990-2009 cars

Cause | Correction
--- | ---
Low oil pressure |

• | Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .

• | Repair or replace as required.

Worn or damaged valve rocker arm |

• | Inspect the rocker arm for wear or missing needle bearings

• | Replace the valve rocker arms as required.

Improper lubrication to the valve rocker arms | Inspect the following components, and repair or replace as required:

• | The valve rocker arm

• | The valve lash adjusters

• | The oil filter bypass valve

• | The oil transfer tube

• | The oil pump and pump screen

• | The engine block oil galleries

Broken valve spring | Replace the valve spring.
Worn or dirty valve lash adjusters | Replace the valve lash adjusters.
Stretched or broken timing chain and/or damaged sprocket teeth | Replace the timing chain and sprockets.
Worn engine camshaft lobes |

• | Inspect the engine camshaft lobes.

• | Replace the camshaft, valve lash adjusters, and rocker arms 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