There are 2 owner-reported fuel system complaints for the 2009 Mercury Grand Marquisin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
I NOTICED SOMETHING HANGING DOWN FROM THE BOTTOM OF THE VEHICLE AND ON INSPECTION DETERMINED IT TO BE A FUEL TANK SUPPORT STRAP. I TOOK THE VEHICLE TO MY MECHANIC FOR FURTHER INSPECTION AND WHEN HE PUT THE VEHICLE ON A LIFT ONE OF THE TWO SUPPORT STRAPS HAD CORRODED COMPLETELY IN TWO AND THE OTHER STRAP WAS LY CORRODED NEARLY AS BAD. IF THE SECOND STRAP HAD ALSO BROKEN AND ALLOWED THE FUEL TANK TO DROP AND DRAG ON THE PAVEMENT THERE COULD HAVE BEEN A SEVERE FIRE. I HAD MY MECHANIC REPLACE BOTH STRAPS IMMEDIATELY TODAY 11-2-16.
TL* THE CONTACT OWNS A 2009 MERCURY GRAND MARQUIS. THE CONTACT STATED THAT AFTER REFUELING, GASOLINE FUEL FUMES EMITTED INSIDE THE VEHICLE AND THE FUEL WOULD DISSIPATE TO HALF OF A TANK WITHIN TWENTY MINUTES OF DRIVING. THE DEALER DIAGNOSED THAT THE FUEL LINE, THE FUEL PUMP, AND THE FUEL SEAL NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED. HOWEVER, THE FAILURE RECURRED. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 35,000.
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