For 1990-2009 cars

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

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

Loose and/or worn valve rocker arm attachments |

1. Inspect the valve rocker arm stud, nut or bolt.
2. Repair or replace as required.

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

• | The valve rocker arm

• | The valve lash adjuster

• | The oil filter bypass valve

• | 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, damaged, or faulty timing chain tensioners | Replace tensioners
Worn engine camshaft lobes |

1. Inspect the engine camshaft lobes.
2. Replace the camshaft and valve lash adjusters 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