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, bolt, and pedestal.
2. Repair or replace, as required.

Worn or damaged valve rocker arm |

1. Inspect the rocker arm for wear or missing needle bearings
2. Replace the valve rocker arms, as required.

Bent or damaged push rod | Inspect the following components and replace, as required:

• | The valve rocker arm

• | The valve push rod

• | The valve lifter

• | The valve lifter guide

• | The piston

Inspect the top of the pistons for valve contact. If the top of the piston shows valve contact, replace the piston and pin assembly.

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

• | The valve rocker arm

• | The valve push rod

• | The valve lifter

• | The oil filter bypass valve

• | The oil pump and pump screen

• | The engine block oil galleries

Broken valve spring | Replace the valve spring and spring shim.
Worn or dirty valve lifters | Replace the valve lifters, as required.
Stretched or broken timing chain and/or damaged sprocket teeth | Replace the timing chain and sprockets.
Worn engine camshaft lobes |

1. Inspect the engine camshaft lobes.
2. 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

Cut or damaged oil pump screen O-ring seal which may cause aeration of the engine oil | Repair, as required. Refer to Oil Pressure Diagnosis and Testing .