GM 6.0 / 8.1 Vortec (gas) recalls and service bulletins

Risk: IF THE SENSOR BECOMES COMPLETELY INOPERATIVE, THE ENGINE WILL QUIT RUNNING AND WILL NOT RE-START. EITHER OF THESE FAILURES CAN INCREASE THE RISK OF A CRASH.

Remedy: DEALERS WILL REPLACE THE CRANKSHAFT POSITION SENSOR FREE OF CHARGE. THE RECALL BEGAN ON DECEMBER 18, 2007. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438 AND GMC AT 1-866-996-9463.

Models in our scope: SIERRA, SILVERADO

Risk: IF THE DAMPER COMES LOOSE, A FUEL LEAK MAY RESULT. FUEL LEAKAGE, IN THE PRESENCE OF AN IGNITION SOURCE, COULD RESULT IN A FIRE.

Remedy: DEALERS WILL REPLACE THE ENGINE FUEL RAIL PULSE DAMPER RETAINER CLIP FREE OF CHARGE. THE RECALL BEGAN ON AUGUST 31, 2006. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438 AND GMC TRUCKS AT 1-866-996-9463.

Models in our scope: SIERRA, SILVERADO

IN A LETTER DATED NOVEMBER 7, 2007, GENERAL MOTORS (GM) REPORTED TO THE OFFICE OF DEFECTS INVESTIGATION (ODI) THAT IT WILL CONDUCT A SAFETY RECALL (07V-521) TO REPLACE THE CRANK POSITION SENSOR (CKP) IN APPROXIMATELY 12,000 MODEL YEAR (MY) 2001 CHEVROLET SILVERADO AND GMC SIERRA VEHICLES EQUIPPED WITH 8.1 LITER ENGINES MANUFACTURED ON OR BEFORE NOVEMBER 15, 2000.ACCORDING TO GM, THE CKP CAN FAIL INTERMITTENTLY OR PERMANENTLY.A PERMANENT CKP FAILURE WOULD RESULT IN AN ENGINE STALL WITHOUT RESTART.AN INTERMITTENT CKP FAILURE COULD CAUSE THE SERVICE ENGINE SOON LIGHT TO ILLUMINATE, THE VEHICLE TO RUN ROUGH OR THE ENGINE TO STALL BUT ALLOWS RESTART.AS A REMEDY, AN IMPROVED CKP WILL BE INSTALLED IN THE SUBJECT VEHICLES.THE RECALL CAMPAIGN WILL START IN DECEMBER 2007. DURING THE PRELIMINARY EVALUATION (PE06-016), AND THIS EA INVESTIGATION, GM AND ODI INDEPENDENTLY CONDUCTED DETAILED REVIEWS OF CERTAIN FIELD DATA TO UNDERSTAND THE NATURE AND RATE OF SUBJECT VEHICLE STALLING DUE TO CKP FAILURES.GM AND ODI REVIEWED GM'S WARRANTY CLAIMS FOR THE CKP WITH THE OBJECTIVE OF ASCERTAINING AN ESTIMATE OF THOSE CLAIMS REPRESENTING AN ENGINE STALL WHILE DRIVING.THE CKP WARRANTY CLAIMS WITHOUT VERBATIM TEXT WERE THE LARGEST SEGMENT OF WARRANTY CLAIMS.USING THOSE CLAIMS, GM SURVEYED VEHICLE OWNERS TO GATHER ADDITIONAL INFORMATION TO DETERMINE IF THE CLAIM WAS ASSOCIATED WITH A STALL WHILE DRIVING EVENT.BASED ON THE SURVEY, GM ESTIMATED THAT APPROXIMATELY 49% OF ALL WARRANTY REPAIRS FOR THE CKP INVOLVED A STALL WHILE DRIVING.ODI?S REVIEW OF GM'S SURVEY DATA PRODUCED A HIGHER ESTIMATE (71%) FOR STALL WHILE DRIVING.GM FURTHER ESTIMATED THE RATE OF STALL WHILE DRIVING FOR THE SUBJECT VEHICLES OVER TIME.IT ESTIMATED STALLING WHILE DRIVING RATES OF 1.6%, 4.6% AND 8.9% AT 1, 3 AND 6 YEARS IN SERVICE RESPECTIVELY.ODI'S REVIEW OF THE GM'S SURVEY DATA FINDS HIGHER ESTIMATED STALL WHILE DRIVING RATES OF 2.2%, 6.8% AND 13% AT 1, 3 AND 6 YEARS IN SERVICE RESPECTIVELY. ODI ALSO CONDUCTED A SURVEY OF VEHICLE OWNERS USING CONSUMER COMPLAINTS REPORTED TO BOTH ODI AND GM.THE OBJECTIVE WAS TO ASCERTAIN THE POTENTIAL SAFETY CONSEQUENCES OF AN ENGINE STALL DUE TO THE ALLEGED DEFECT.WITH RESPECT TO THE ABILITY TO RESTART THE VEHICLE AFTER A STALL, 11% REPORTED IMMEDIATE RESTART, 69% REPORTED DELAYED RESTART AND 20% REPORTED NO RESTART.OVER HALF NOTED AT LEAST ONE ENGINE STALL INCIDENT AT SPEEDS IN EXCESS OF 40MPH. ABOUT ONE-THIRD NOTED THE VEHICLE WAS STRANDED EITHER PARTIALLY OR FULLY IN A LANE OF TRAFFIC AFTER THE ENGINE STALL.ALL OF THE CONSUMERS SURVEYED NOTED MULTIPLE STALLING EVENTS PRIOR TO PROPER DIAGNOSIS AND REPLACEMENT OF THE CKP.BASED ON GM'S DECISION TO CONDUCT A SAFETY RECALL, THIS INVESTIGATION IS CLOSED.

Models in our scope: Chevrolet SILVERADO 2500, Chevrolet SILVERADO 2500 HD, Chevrolet SILVERADO 3500, Chevrolet SILVERADO 3500 HD, Gmc SIERRA 2500, Gmc SIERRA 2500 HD, Gmc SIERRA 3500, Gmc SIERRA 3500 HD

THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION (PE06-016) ON MAY 4, 2006 BASED ON ELEVEN VEHICLE OWNER QUESTIONNAIRES (VOQS) AND EARLY WARNING (EWR) DATA ALLEGING SUDDEN ENGINE SHUTDOWN WHILE DRIVING AS A RESULT OF CRANK POSITION SENSOR FAILURES IN MY 2001-2002 GENERAL MOTORS C/K PLATFORM VEHICLES EQUIPPED WITH 8.1L ENGINES.IN RESPONSE TO AN INFORMATION REQUEST LETTER SENT BY ODI, GENERAL MOTORS (GM) PROVIDED OWNER COMPLAINT INFORMATION, FIELD REPORTS AND WARRANTY CLAIM DATA BASED ON A POPULATION OF 108,338 VEHICLES. THE DATA WAS CATEGORIZED BY ENGINE STALLS WHILE DRIVING, ENGINE STALLS WITH AN UNKNOWN DRIVING CONDITION, NO START CONDITIONS AND CLAIMS WHERE IT WAS INDETERMINATE IF AN ENGINE STALL OCCURRED WHILE DRIVING.GENERAL MOTOR'S RESPONSE INCLUDED 1,213 OWNER COMPLAINTS AND FIELD REPORTS OF WHICH 289 WERE CATEGORIZED AS ENGINE STALLS WHILE DRIVING ALLEGEDLY CAUSED BY CRANK POSITION SENSOR FAILURES. GENERAL MOTORS ALSO SUBMITTED WARRANTY CLAIMS FROM ITS REGULAR WARRANTY (5 YEARS/50,000 MILES) AND FROM ITS EXTENDED WARRANTY DATABASE. FROM THE REGULAR WARRANTY DATABASE THERE WERE 3,140 CLAIMS OF CRANK POSITION SENSOR REPLACEMENT OF WHICH 147 CLAIMS WERE FROM CONSUMERS ALLEGING ENGINE STALL WHILE DRIVING.GM STATED THAT 2,841 OF THE CLAIMS WERE INDETERMINATE IF AN ENGINE STALL OCCURRED WHILE DRIVING.FROM ITS EXTENDED WARRANTY DATABASE, GM SUBMITTED 1,561 CLAIMS OF CRANK POSITION SENSOR FAILURE THAT IT ALSO STATED WERE INDETERMINATE AS TO WHETHER AN ENGINE STALL OCCURRED WHILE DRIVING.IN TOTAL, GM REPORTS 4,701 CLAIMS OF CRANK POSITION SENSOR FAILURE COMBINING REGULAR WARRANTY AND EXTENDED WARRANTY.SIMILAR TO GM'S STATISTICAL ANALYSIS, ODI'S ANALYSIS SHOWED THAT THE FAILURE RATE FOR WARRANTY CLAIMS OF ENGINE STALL WHILE DRIVING AT THREE YEARS IN SERVICE IS LOW (LESS THAN 1%).HOWEVER, FURTHER ANALYSIS DETERMINED THAT THE MY 2001 VEHICLE BUILD PERIOD FROM MAY 2000 THROUGH OCTOBER 2000 HAD SIGNIFICANTLY HIGHER (MORE THAN FOUR TIMES) CRANK POSITION FAILURE RATES IN BOTH CONSUMER COMPLAINT DATA AND WARRANTY CLAIM DATA THAN IN THE BUILD PERIOD FROM NOVEMBER 2000 THROUGH JULY 2001.ADDING THE CLAIMS OF KNOWN ENGINE STALL WHILE DRIVING AND CLAIMS WHERE ENGINE STALL WAS INDETERMINATE, THE FAILURE RATE AT THREE YEARS IN SERVICE FOR THIS POPULATION IS OVER 6%.AN ENGINEERING ANALYSIS (EA06-016) HAS BEEN OPENED TO FURTHER ASSESS THE FREQUENCY AND POTENTIAL SAFETY CONSEQUENCES ASSOCIATED WITH THE ALLEGED DEFECT IN VEHICLES BUILT FROM MAY 2000 THROUGH OCTOBER 2000.

Models in our scope: Chevrolet SILVERADO, Gmc SIERRA

THIS INVESTIGATION INVOLVES THE GENERAL MOTORS CORPORATION (GM)THROTTLE BODY (TB) UTILIZED IN MODEL YEAR (MY) 1999-2002 SILVERADO, SIERRA, TAHOE, SUBURBAN, AVALANCHE AND YUKON (SUBJECT VEHICLE(S)) WITH 4.8L, 5.3L, AND 6.0L ENGINES. THE TB VALVE MAY INTERMITTENTLY STICK IN A CLOSED POSITION.IN SUCH A SITUATION, AN OPERATOR MAY APPLY ADDITIONAL ACCELERATOR PEDAL FORCE TO INCREASE ENGINE SPEED.THE APPLICATION OF ADDITIONAL ACCELERATOR PEDAL FORCE, TO OPEN A STUCK THROTTLE VALVE, MAY OPEN THE THROTTLE VALVE MORE THAN INTENDED AND, IN TURN, ACCELERATE THE ENGINE AND VEHICLE MORE THAN INTENDED AND REASONABLY EXPECTED BY THE DRIVER.ON AUGUST 1, 2002, THE OFFICE OF DEFECTS INVESTIGATION (ODI), OF THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION (NHTSA), OPENED THIS ENGINEERING ANALYSIS.THE INVESTIGATION REVEALED THAT TWO FACTORS MAY CAUSE THE DEFECT: 1) TB MANUFACTURING PROCESS PROBLEMS; AND 2) ACCUMULATION OF DEPOSITS (A PCV SYSTEM BY-PRODUCT) ON OR AROUND THE TB THROTTLE VALVE AND BORE.ODI CONCLUDES THAT THE TB PERFORMS IN A DEFECTIVE MANNER AFTER ANALYZING GM?S DATA SUBMISSIONS, AND TEST DATA COLLECTED BY THE VEHICLE RESEARCH AND TEST CENTER (VRTC).FIFTY-NINE CRASHES ARE ALLEGED TO HAVE OCCURRED AS A RESULT OF GM?S TB DEFECT.THE MAJORITY OF THE CRASHES INVOLVE A SINGLE VEHICLE, ENGAGING IN A CLOSE QUARTER VEHICLE MANEUVER (OR LOW SPEED), AND CAUSING ONLY MINOR PROPERTY DAMAGE.FOUR OUT OF THE FIFTY-NINE CRASHES INVOLVE INJURY, AND THOSE INJURIES WERE MINOR.ALTHOUGH GM?S TB IS DEFECTIVE, BASED ON THE EVIDENCE GATHERED, ODI HAS FOUND THAT THE ACCELERATOR PEDAL FORCE REQUIRED TO OPEN A STUCK THROTTLE VALVE IS NEGLIGIBLE, AND THE THROTTLE VALVE DOES NOT STICK IN THE OPEN POSITION.THEREFORE THIS ENGINEERING ANALYSIS (EA02-015) WILL BE CLOSED AT THIS TIME.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST.FOR A DETAILED DISCUSSION OF THE TB COMPONENT AND TESTING, PLEASE SEE THE ATTACHED REPORT.

Models in our scope: Chevrolet SILVERADO, Gmc SIERRA