For 1990-2009 cars

Condition | Action
--- | ---
Worn valve guides |

1. Inspect the valves and valve guides.
2. Repair or replace all damaged components.

Worn valve stem oil seals |

1. Inspect the valve stem oil seals.
2. Repair or replace all damaged components.

Excessive piston-to-cylinder bore clearance |

1. Perform compression tests to determine the cause.
2. Inspect the piston rings for low ring tension, broken or worn rings.
3. Inspect cylinder bore.
4. Repair or replace all damaged components.