For 1990-2009 cars

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

• | Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing

• | Repair or replace damaged components as required.

Improper lubrication of the valve train components |

• | Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing .

• | Inspect the valve lifters.

• | Inspect the oil filter bypass valve.

• | Inspect the oil pump and pump screen.

• | Inspect the engine block oil galleries.

• | Repair or replace damaged components as required.

Broken valve spring |

• | Inspect the valve springs.

• | Repair or replace damaged components as required.

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

• | Inspect the valves.

• | Inspect the valve guides.

• | Repair or replace damaged components as required.

Worn or damaged valve guide |

• | Inspect the valve guides.

• | Inspect the valves.

• | Repair or replace damaged components as required.

Worn, damaged or dirty valve lifter |

• | Inspect the valve lifters.

• | Repair or replace damaged components as required.

Worn or damaged camshaft lobes |

• | Inspect the engine camshaft lobes.

• | Repair or replace damaged components as required.

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

• | Inspect the timing chain and sprockets.

• | Repair or replace damaged components as required.

Worn, damaged or improperly installed chain belt tensioner, if equipped |

• | Inspect the timing chain tensioner.

• | Repair or replace damaged components as required.