Oil Pressure Light - On or Loss of Oil Pressure at Idle
Bulletin 86-6-6ADate Apr. '86
Ref. No. 86-047A-6
SUBJECT: OIL PRESSURE LIGHT ON AT IDLE OR LOSS OF OIL PRESSURE AT IDLE
MODELS AFFECTED: 1985-86 3.0L ENGINES (VIN CODE L) AND 1986 3.8L ENGINES (VIN CODES B & 3)
NOTE: THIS BULLETIN SUPERCEDES BULLETIN 86-6-6, FEBRUARY, 1986. PLEASE DISCARD PREVIOUS BULLETIN AND REPLACE WITH THIS ONE, RE-RELEASED TO PROVIDE ADDITIONAL INFORMATION.
If a condition of no oil pressure at idle occurs on one of the above engines, the oil pressure relief valve may be sticking in the bore in the engine front cover. To check for freeness, remove the oil filter adapter assembly. Spring tension behind the valve should cause it to pop out of the bore once the adapter assembly is removed. If it does not, it is sticking or binding and needs to be freed up.
PRESSURE REGULATOR VALVE:
Simply forcing the valve in board as far as possible several times against the spring pressure behind it will usually free it up. To ensure continued freeness of the valve it should be removed and a very small chamfer should be formed at the outer edge of the outside of the valve at the stepped end using crocus cloth or extremely fine emery paper. (See illustration).
The first land of the bore inside the timing chain cover should also be checked for smoothness. A thorough cleaning of the bore should be performed to remove all foreign material before reassembly.
Additionally, the oil filter adapter gasket may have a tear area in the gasket surface that covers an oil channel port in the timing cover. Pieces of the gasket may stick the oil pressure relief valve. To correct this condition, clean cover oil passages of any gasket material and replace gasket with a new one, Part Number 25529916. The new gasket has an irregular shaped hole to avoid exposure of gasket material to the oil channel.