NHTSA Complaint #10137551 — 2003 JEEP GRAND CHEROKEE

MY 2003 JEEP GRAND CHEROKEE, WITH LESS THAN 33,000 MILES, WAS REPAIRED FOR THE SAME PROBLEM TWICE THIS YEAR, ON 9 FEB AND 26 JUL 2005. THE REPAIRS WERE DONE AT 2 DIFFERENT JEEP-CERTIFIED SERVICE FACILITIES, AND FOCUSED ON DECARBONIZATION CLEANINGS. BASED ON THE INVOICES AND MY OWN RESEARCH, IT'S CLEAR THIS PROBLEM HAS SEVERAL INTERRELATED FACTORS: MULTIPLE CYLINDER MISFIRES, AND EXHAUST VALVE OBSTRUCTION WITH EXCESSIVE CARBON BUILDUP. FURTHER, IT IS DIRECTLY LINKED TO SHORT-TRIP/CITY DRIVING. A FEW WEEKS AFTER THE SECOND REPAIR, I HAD AN INDEPENDENT (NON-JEEP) ACE-CERTIFIED MECHANIC INSPECTION. HIS FINDINGS INDICATE THAT THE MISFIRES CONTINUE; THE UNDERLYING PROBLEM APPARENTLY PERSISTS. IN THE BIG PICTURE, JEEP DID ACKNOWLEDGE THE PROBLEM IN TSB-09-003-03, ENCOMPASSING A SPAN OF MODELS, FROM 1999 TO 2004, W/ 4.0L ENGINES. THE TSB PRESCRIBES A VALVE CHECK AND POSSIBLE CLEANING, BUT DOES NOT ADDRESS THE ROOT CAUSE OF THE MISFIRES AND CARBON BUILD-UP. IN THE SMALLER PICTURE, I MIGHT MENTION: THE JEEP REPRESENTATIVE A/W THE JULY REPAIR TOLD ME THIS PROBLEM WAS THE RESULT OF USING 'CHEAP GASOLINE'. THIS THEORY IS NOT SUPPORTED BY ANYTHING I'VE LEARNED IN MY OWN RESERACH. IT IS JUST NOT FEASIBLE THAT GASOLINE GRADE COULD CAUSE SUCH AN EXTENT OF CARBON BUILD-UP TWICE IN 6 MONTHS, ESP WITH SUCH LOW MILEAGE. I SHOULD PROBABLY ALSO ADD THAT I DON'T KNOW THE ABSOLUTE ANSWER TO THIS PROBLEM. THERE IS A GOOD DEAL OF REFERENCE MATERIAL ONLINE ID'ING THIS AS A CHRONIC PROBLEM W/ GRAND CHEROKEE, YET NO CLEARCUT PERMANENT SOLUTION. I HAVE SUPPORTING DOCUMENTATION ON WHAT I STATE HERE, AND WILL BE HAPPY TO FOLLOW UP IN WRITING IF THAT WILL HELP. LASTLY- SINCE MOST OF MY VEHICLE USE IS SHORT-TRIP CITY DRIVING, I AM WORRIED THAT I MAY FACE LONG-TERM INCONVENIENCE, EXPENSE, AND SAFETY RISKS. MY INTENT IS NOT TO CAUSE PROBLEMS FOR JEEP- I SIMPLY WANT MY VEHICLE TO BE FUNCTIONING AND SAFE FOR MY FAMILY. *JB