LACK OF POWER, LOSS OF OIL PRESSURE. Cadillac Concours 1994

For 1990-2009 cars

# LACK OF POWER, LOSS OF OIL PRESSURE

REVISION: 12/11/95

THIS BULLETIN IS BEING REVISED TO ADD THE 1996 MODEL YEAR. PLEASE DISCARD BULLETIN 47-61-32 (SECTION 6 - ENGINE). ----------------------------------------------------------------------

REVISION: 03/11/96

THIS BULLETIN IS BEING REVISED TO ADD CLARIFICATION TO CORRECTION. PLEASE DISCARD BULLETIN 47-61-32A (SECTION 6 - ENGINE). ----------------------------------------------------------------------

#### SUBJECT: LACK OF POWER, LOSS OF OIL PRESSURE (CHECK HARMONIC BALANCER BOLT TORQUE AND FLUSH OIL PUMP RELIEF VALVE)

#### MODELS: 1993 CADILLAC ALLANTE 1993-96 CADILLAC ELDORADO AND SEVILLE 1994-96 CADILLAC CONCOURS 1996 CADILLAC SEDAN DEVILLE WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

1995-96 OLDSMOBILE AURORA WITH 4.0L ENGINE (VIN C - RPO L47)

#### CONDITION:

SOME OWNERS MAY COMMENT ON LOW OIL PRESSURE WHICH MAY DISPLAY A "LOW OIL PRESSURE" MESSAGE AND/OR A "MALFUNCTION INDICATOR LAMP" (SERVICE ENGINE SOON) TELLTALE. VEHICLE OWNERS MAY COMMENT THAT THESE TELLTALE MESSAGES ILLUMINATE AT ENGINE SPEEDS OF 1000 RPM AND ABOVE.

#### CAUSE:

LACK OF OIL PRESSURE MAY BE CAUSED BY:

- PARTICLES FROM THE MANUFACTURING PROCESS STICKING THE OIL PUMP RELIEF VALVE, NOT ALLOWING THE VALVE TO SEAL TO ITS SEAT WHICH DOES NOT ALLOW THE PUMP TO PRIME.

- A LOOSE HARMONIC BALANCER BOLT WHICH WILL RESULT IN THE OIL PUMP NOT TURNING.

#### CORRECTION:

ENSURE THE HARMONIC BALANCER BOLT IS TIGHTEN TO SPEC. THE CORRECT TORQUE VALUE FOR THIS BOLT IS 60 N.M (44 LB FT) PLUS 120 DEGREES FOR 1993-95 ENGINES WITH AN M18 BOLT AND 50 N.M (37 LB FT) PLUS 120 DEGREES FOR 1996 ENGINES WITH AN M14 BOLT.

#### NOTICE: A SMALL NUMBER OF 1995 ENGINES WERE BUILT WITH CRANKSHAFTS EQUIPPED WITH THE M14 BOLT. IDENTIFY THE SIZE OF THE BOLT TO DETERMINE THE PROPER TORQUE SPECIFICATION.

IF THE BOLT IS TO SPECIFICATION, THE CAUSE OF THE LOW OIL PRESSURE IS INTERNAL TO THE PUMP.

TO REMOVE PARTICLES FROM THE RELIEF VALVE IN THE OIL PUMP, PERFORM THE FOLLOWING PROCEDURE:

1. ADD AN **ADDITIONAL** 10 TO 12 QUARTS (LITERS) OF ENGINE OIL TO THE ENGINE. THIS WILL IMMERSE THE PUMP COMPLETELY IN OIL.

2. START THE ENGINE AND REPEATEDLY OPEN THE THROTTLE (REV THE ENGINE) FROM IDLE TO 3500 RPM. THIS WILL ALLOW THE PUMP TO PRIME; CYCLING THE RELIEF VALVE FORCES ANY DEBRIS FROM THE RELIEF VALVE.

#### IMPORTANT: DO NOT OPERATE THE ENGINE ABOVE 3500 RPM. DOING SO WILL AERATE THE ENGINE OIL AND/OR FORCE EXCESS ENGINE OIL INTO THE PCV SYSTEM. **DO NOT DRIVE THE VEHICLE WHILE THE ADDITIONAL OIL IS IN THE ENGINE.**

AFTER THE ENGINE HAS SUFFICIENT OIL PRESSURE, ANY VALVETRAIN NOISE ASSOCIATED WITH THIS LOW OIL PRESSURE CONDITION SHOULD NOT BE EVIDENT UPON RESTARTING THE VEHICLE AND THE LOW OIL PRESSURE AND MALFUNCTION INDICATOR LAMP (SERVICE ENGINE SOON) MESSAGES SHOULD NOT REMAIN ILLUMINATED.

3. AFTER ENGINE HAS SUFFICIENT OIL PRESSURE, DRAIN THE CRANKCASE. REINSTALL THE ENGINE OIL PAN DRAIN PLUG.

4. ADD 7 QUARTS OF ENGINE OIL AND CHECK THE OIL LEVEL. MAKE SURE THE VEHICLE IS ON A LEVEL SURFACE AND THE ENGINE OPERATING TEMPERATURE IS 100 DEGREES CELSIUS WHEN CHECKING THE OIL LEVEL WITH THE ENGINE STOPPED FOR 15-20 SECONDS.

WARRANTY INFORMATION FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION: J0989 LABOR HOURS: 0.5 HOUR

FIGURES: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

COPYRIGHT 1994. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.