There are 8 owner-reported powertrain & transmission complaints for the 2003 Mercury Grand Marquisin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
PAINT PEELING WHINE FROM REAL DIFFERENTIAL
TL* THE CONTACT OWNS A 2003 MERCURY GRAND MARQUIS GS. THE CONTACT WAS DRIVING 35 MPH WHEN AN ABNORMAL NOISE WAS HEARD FROM UNDER THE VEHICLE. THE VEHICLE WAS TAKEN TO A LOCAL REPAIR SHOP WHERE THE MECHANIC CONFIRMED THAT THE TRANSMISSION NEEDED TO BE REPLACED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND THE VEHICLE WAS REPAIRED. THE FAILURE MILEAGE WAS 52,000 AND THE CURRENT MILEAGE WAS 54,000.
TL* THE CONTACT OWNS A 2003 MERCURY GRAND MARQUIS. THE CONTACT STATED THERE WAS AN ABNORMAL NOISE FROM THE REAR AXLE. THE DEALER WAS UNABLE TO DIAGNOSE THE FAILURE YET THE FAILURE PERSISTED. AT 15,000 MILES, THE CONTACT TOOK THE VEHICLE BACK TO THE DEALER WITH CONCERNS OF THE NOISE. AGAIN, THE DEALER WAS UNABLE TO DIAGNOSE THE FAILURE. AT 23,000 MILES THE VEHICLE WAS TAKEN TO THE DEALER A THIRD TIME. THE DEALER ADVISED THAT THE REAR AXLE, BEARINGS, SEALS AND THE WHEEL SHAFT WOULD NEED TO BE REPLACED. THE REPAIR WAS COMPLETED AT THE CONTACT'S EXPENSE. THE FAILURE DID NOT PERSIST. THE FAILURE MILEAGE WAS 8,000 AND THE CURRENT MILEAGE WAS 27,000.
AUTOMATIC TRANSMISSION SHIFTS ERRATICALLY WHEN IN CRUISE MODE, LESS THAN 70,000 MILES ON VEHICLE, HAS ALMOST CAUSED ACCIDENT SEVERAL TIMES. HAVE TO DIS-ENGAGE CRUISE CONTROL AND SHUT OFF OVERDRIVE TO CURE IT, AND KEEPS OCCURRING ALTHOUGH LESS FREQUENTLY. *TR
REAR AXLE BEARING FAILURE ON 2003 MERCURY GRAND MARQUIS. PE4010. THE AXLES ARE IMPROPERLY HEAT TREATED AND FAIL DUE TO NORMAL LOADS. THIS CAR IS NOT A POLICE VEHICLE. THERE IS A CLEAR DEFECT IN THE AXLES OF ALL SIMILAR BODY STYLES. *JB
2003 MERCURY GRAND MARQUIS CUSTOMER HAS HAD THE HEAD AND INTERIOR LIGHTS REPAIRED THREE TIMES AND WANTS TO BE REIMBURSED FOR REPAIRS CUSTOMER HAS EXTENDED SERVICE PLAN **CC THE PROBLEM WAS DIAGNOSED AS THE POWER CONTROL MODULE. THE CONSUMER STATED THE PROBLEM WAS MIS-DIAGNOSED THREE TIMES AS THE PROBLEM BEING THE LIGHTING CONTROL MODULE. *JB
THE VEHICLE'S SHIFTER JUMPED OUT OF PARK AND INTO REVERSE. AS A RESULTED THE VEHICLE ROLLED BACKWARDS AND WAS INVOLVED IN A MINOR COLLISION. *AK
WHEN THE CONSUMER PUT THE GEAR INTO REVERSE ON AN INCLINE, THE VEHICLE CONTINUED TO MOVE FORWARD. *NLM PH *JB
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026