POSSIBLE CAUSES
1. CCV System malfunction
2. Defective valve stem seal(s)
3. Worn or broken piston rings
4. Scuffed pistons/cylinder walls
5. Carbon in oil control ring groove
6. Worn valve guides
7. Piston rings fitted too tightly in grooves
CORRECTION
1. (Refer to 25 – EMISSIONS CONTROL/EVAPORATIVE EMISSIONS – DESCRIPTION) for correct operation
2. Repair or replace seal(s)
3. Hone cylinder bores. Install new rings
4. Hone cylinder bores and replace pistons as required
5. Remove rings and de-carbon piston
6. Inspect/replace valve guides as necessary
7. Remove rings and check ring end gap and side clearance. Replace if necessary