GRUNT/SQUEAK SHIFTING FROM PARK TO REVERSE/DR.. Pontiac Tempest (Canada) 1992

REVISION 08/24/93

THIS BULLETIN IS BEING REVISED TO PROVIDE UPDATED PARTS INFORMATION (LOWER ENGINE MOUNT STRUT, P/N 22595752), INCLUDE VIN BREAKPOINTS, AND ADD A LABOR OPERATION NUMBER.

REVISION 09/07/93

THIS BULLETIN IS BEING REVISED TO CORRECT ENGINE APPLICATIONS, SPECIFY EXCEPTIONS FOR RPO LN2, AND TO CLARIFY THAT IT IS APPLICABLE TO AUTOMATIC TRANSMISSIONS ONLY. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE:

CHEVROLET 93-102-6 PONTIAC 93-6-29A OLDSMOBILE 93-T-41A BUICK 93-6-10 GM OF CANADA 93-6A-109 ---------------------------------------------------------------------- REVISION: 06/07/94

THIS BULLETIN IS BEING REVISED TO ADD ENGINE APPLICATIONS AND REVISE/ ADD PART NUMBERS. PLEASE DISCARD BULLETIN 336102 (GROUP REFERENCE 6 - ENGINE). ----------------------------------------------------------------------

SUBJECT: GRUNT, SQUAWK OR SQUEAK NOISE WHEN SHIFTING FROM PARK TO REVERSE OR DRIVE AND/OR UNDER HEAVY ENGINE LOAD (USE DIAGNOSTIC PROCEDURE)

MODELS: 1992-93 CHEVROLET CORSICA/BERETTA 1992-93 BUICK SKYLARK 1992-93 OLDSMOBILE ACHIEVA 1992-93 PONTIAC GRAND AM

ENGINE APPLICATION:

2.3L (VIN 3 - RPO L40) 2.2L (VIN 4 - RPO LN2) 2.3L (VIN D - RPO LD2) 3.3L (VIN N - RPO LG7) 3.1L (VIN T - RPO LH0) WITH AUTOMATIC TRANSMISSION ONLY

CONDITION:

SOME OWNERS MAY COMMENT ABOUT A GRUNT, SQUAWK OR SQUEAK NOISE WHEN SHIFTING FROM PARK TO REVERSE OR DRIVE. THE SAME NOISE MAY ALSO BE HEARD DURING HEAVY ENGINE LOAD, SUCH AS QUICK ACCELERATION. THE NOISE WILL MOST LIKELY OCCUR IN COLD AMBIENT TEMPERATURES OR WET CONDITIONS. THIS NOISE MAY BE MISDIAGNOSED AS COMING FROM THE EXHAUST SEAL (EXCEPT RPO LN2). USE THE PROCEDURE FOUND IN "SERVICE INFORMATION" BELOW TO DETERMINE THE LOCATION OF THE NOISE.

CAUSE:

ON 1992-93 VEHICLES, THE LOWER ENGINE MOUNT STRUT RUBBER MAY MOVE AGAINST ITS METAL CASTING DURING THE SHIFT OR HEAVY ENGINE LOADS. ON 1992 2.3L ENGINES, A SIMILAR NOISE CAN BE CAUSED BY HIGH CLAMP LOAD ON THE EXHAUST SEAL. THIS CONDITION IS ADDRESSED BY CORPORATE BULLETIN NUMBER 276101R (DIVISIONAL NUMBERS LISTED BELOW):

PONTIAC 92-6-20A OLDSMOBILE 92-T-54A BUICK 92-6-4A GM OF CANADA 92-623-102

CORRECTION:

WHEN THE DIAGNOSIS INDICATES THE EXHAUST SYSTEM IS AT FAULT ON 1992 2.3L ENGINES, REFER TO CORPORATE BULLETIN NUMBER 276101R TO REPAIR THE EXHAUST SYSTEM. ALL 1993 MODEL YEAR PRODUCTION VEHICLES WITH 2.3L ENGINES HAVE A REDESIGNED EXHAUST MANIFOLD AND SEAL. INSTALL REVISED LOWER ENGINE MOUNT STRUT, P/N 22594147 - 2.2L AND 2.3L, OR P/N 22637875 - 3.1L AND 3.3L (DO NOT USE FOR 1994 MODELS) WHEN DIAGNOSIS INDICATES THE LOWER ENGINE MOUNT STRUT IS AT FAULT. VEHICLES BUILT AFTER THE FOLLOWING VIN BREAKPOINTS HAVE THE REVISED LOWER ENGINE MOUNT STRUT INSTALLED IN PRODUCTION:

2.3L AND 2.2L ENGINES WITH AUTOMATIC TRANSMISSIONS:

DIVISION PLANT VIN ======== ===== ===

OLDSMOBILE LANSING (A) PM035485 BUICK LANSING (B) PC296499 PONTIAC LANSING (A) PM602516 PONTIAC LANSING (B) PC789942 CHEVROLET WILMINGTON PY244358

ALL 3.1L AND 3.3L ENGINES WITH AUTOMATIC TRANSMISSIONS.

SERVICE INFORMATION:

IMPORTANT: TORQUE AXIS MOUNTING SYSTEMS ALLOW MORE ENGINE MOVEMENT THAN OTHER ENGINE MOUNTING SYSTEMS. THIS MOVEMENT MAY SEEM EXCESSIVE BUT THAT IS THE DESIGN INTENT OF THE MOUNTING SYSTEM. DO NOT REPLACE ANY TORQUE AXIS MOUNTS FOR MOVEMENT UNLESS THERE IS DAMAGE TO THE MOUNT OR RUBBER.

DIAGNOSIS:

SPRAY 3M SILICONE LUBRICANT P/N 51135-08935 OR EQUIVALENT ON THE LOWER ENGINE MOUNT STRUT BETWEEN THE RUBBER AND METAL. NOTE: USE ONLY SILICONE TYPE LUBRICANT BETWEEN THE RUBBER AND METAL SURFACES. ANY OTHER LUBRICANT WILL DESTROY THE RUBBER MAKING REPLACEMENT OF THE LOWER ENGINE MOUNT STRUT NECESSARY.

IF THE NOISE STILL EXISTS, REFER TO CORPORATE BULLETIN NUMBER 276101R FOR EXHAUST SYSTEM SEALS AND SUBMIT LABOR OPERATION J0005 (EXCEPT RPO LN2). IF THE NOISE IS GONE, REPLACE THE LOWER ENGINE MOUNT STRUT WITH P/N 22594147 (2.2 & 2.3L ENGINES, DO NOT USE FOR 1994 MODELS) OR P/N 22637875 (3.1L AND 3.3L ENGINES, DO NOT USE FOR 1994 MODELS) AND SUBMIT LABOR OPERATION J1520. THE SILICONE LUBRICANT WILL ELIMINATE THE CONDITION FOR A SHORT TIME ONLY.

PARTS ARE EXPECTED TO BE AVAILABLE ON JUNE 20, 1994.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: J0005 - LOWER ENGINE MOUNT STRUT DIAGNOSIS J1520 - LOWER ENGINE MOUNT STRUT DIAGNOSIS AND REPLACE

LABOR TIME: 0.2 HRS. - J0005 0.4 HRS. - J1520

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.