ENGINE STALL AT COLD START, ROUGH IDLE, OIL FILTER. Oldsmobile Achieva 1996

REVISION: 05/08/97

THIS BULLETIN IS BEING REVISED TO ADD CHEVROLET MALIBU TO MODELS. PLEASE DISCARD CORPORATE BULLETIN 77-61-09 (SECTION 6--ENGINE). ______________________________________________________________________

REVISION: 10/16/97

THIS BULLETIN IS BEING REVISED TO ADD A NEW SERVICE PROCEDURE AND TO REVISE THE SERVICE PARTS INFORMATION. PLEASE DISCARD CORPORATE BULLETIN 77-61-09A (SECTION 6--ENGINE). ______________________________________________________________________

SUBJECT: ENGINE STALL AT COLD START, ROUGH IDLE, OIL FILTER EXPANSION, HIGH OIL PRESSURE, AND P0300 DTCS (REPLACE OIL PUMP COVER ASSEMBLY)

MODELS: 1995-97 BUICK SKYLARK 1995-97 CHEVROLET CAVALIER 1997 CHEVROLET MALIBU 1995-97 OLDSMOBILE ACHIEVA 1995-97 PONTIAC SUNFIRE, GRAND AM 1996-97 TOYOTA CAVALIER WITH 2.3L, 2.4L ENGINE (VINS D, T - RPOS LD2, LD9)

CONDITION:

SOME VEHICLES MAY EXHIBIT ONE OF A NUMBER OF CONCERNS RELATED TO THIS CONDITION. THE MOST COMMON SYMPTOM WILL BE STALLING ON INITIAL COLD STARTING, FOLLOWED BY HARD RESTARTING. OTHER CONCERNS MAY INCLUDE OIL FILTER CANISTER EXPANSION OR LEAKAGE AND HIGH OIL PRESSURE WHEN CHECKED WITH A GAUGE. SOME VEHICLES MAY ALSO EXHIBIT DIAGNOSTIC TROUBLE CODES P0300, P0301, P0302, P0303, AND P0304 INDICATING ENGINE MISFIRE CONDITIONS. OIL PRESSURE AT OPERATING TEMPERATURE MAY EXCEED 827 KPA (120 PSI).

CAUSE:

DUE TO A CONDITION OF THE RELIEF VALVE AND THE RELIEF VALVE BORE, THE RELIEF VALVE MAY INTERMITTENTLY BECOME STUCK CAUSING HIGH OIL PRESSURE. THE INCREASED OIL PRESSURE MAY CAUSE THE HYDRAULIC VALVE LIFTERS TO RAISE THE VALVES OFF OF THEIR SEATS CREATING A LOSS OF COMPRESSION AND ENGINE MISFIRE OR STALLING ON INITIAL STARTUP.

DIAGNOSIS:

IF THE VEHICLE EXHIBITS ANY OF THE ABOVE CONDITIONS, INSTALL AN OIL PRESSURE GAUGE CALIBRATED TO READ AT LEAST 1034 KPA (150 PSI) IN THE OIL PRESSURE PORT ON THE INTAKE CAMSHAFT CARRIER AND OBSERVE OIL PRESSURE AT 3000 RPM. THE OIL PRESSURE, EVEN IN EXTREME COLD, SHOULD NOT EXCEED 689 KPA (100 PSI). WITH THE ENGINE OIL AT OPERATING TEMPERATURE, OIL PRESSURE SHOULD NOT EXCEED 586 KPA (85 PSI). AT 3000 RPM.

CORRECTION:

IF THE OIL PRESSURE EXCEEDS THESE LIMITS, REPLACE THE OIL PUMP COVER WITH AN OIL PUMP COVER THAT HAS AN IMPROVED PRESSURE RELIEF VALVE AND PRESSURE RELIEF VALVE BORE.

SERVICE PROCEDURE 1. REMOVE THE RADIATOR OUTLET PIPE AND THE ENGINE OIL PAN, USING PROCEDURES OUTLINED IN SECTION 6A7 OR THE ENGINE MECHANICAL SECTION OF THE APPROPRIATE SERVICE MANUAL.

2. REMOVE THE BALANCE SHAFT DRIVE CHAIN COVER.

3. REMOVE THE BALANCE SHAFT DRIVE CHAIN TENSIONER SHOE.

IMPORTANT: DO NOT REMOVE THE BALANCE SHAFT DRIVE CHAIN OR BALANCE SHAFT DRIVE SPROCKET.

4. REMOVE ONLY THE OIL PUMP COVER ASSEMBLY.

5. INSTALL THE NEW OIL PUMP COVER ASSEMBLY GM P/N 24577081.

6. TIGHTEN THE FOUR LONG BOLTS TO 12 NM (106 LB IN).

7. TIGHTEN THE SHORT BOLT TO 10 NM (89 LB IN).

8. INSTALL THE BALANCE SHAFT DRIVE CHAIN TENSIONER SHOE AND THE BALANCE SHAFT DRIVE CHAIN COVER USING PROCEDURES OUTLINED IN SECTION 6A7 OR THE ENGINE MECHANICAL SECTION OF THE APPROPRIATE SERVICE MANUAL.

IMPORTANT: DO NOT USE EXCESSIVE PRESSURE WHEN INSTALLING THE BALANCE SHAFT DRIVE CHAIN TENSIONER. EXCESSIVE BALANCE SHAFT DRIVE CHAIN TENSION WILL RESULT IN NOISE AND WEAR CONCERNS.

9. REINSTALL THE ENGINE OIL PAN AND THE RADIATOR OUTLET PIPE, REFER TO SECTION 6A7 OR THE ENGINE MECHANICAL SECTION OF THE APPROPRIATE SERVICE MANUAL.

PARTS INFORMATION:

WHENEVER ORDERING PARTS, REFER TO THE FOLLOWING PART NUMBER: DESCRIPTION COVER ASSEMBLY, ENGINE OIL PUMP GM PART NUMBER 24577081

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE ONE OF THE APPLICABLE WARRANTY LABOR OPERATION NUMBERS BELOW:

PROCEDURE OIL PUMP COVER ASSEMBLY, REPLACE VEHICLE LINE N-CAR LABOR OPERATION J1025 LABOR HOURS AUTO TRANS (2.4) MANUAL TRANS (2.4)

PROCEDURE OIL PUMP COVER ASSEMBLY, REPLACE VEHICLE LINE N-CAR MALIBU LABOR OPERATION J1025 LABOR HOURS AUTO TRANS (1.8) MANUAL TRANS (N/A)

PROCEDURE OIL PUMP COVER ASSEMBLY, REPLACE VEHICLE LINE J-CAR LABOR OPERATION J1025 LABOR HOURS AUTO TRANS (2.3) MANUAL TRANS (2.3)

FIGURES: 00 ATTACHMENTS: 00

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.