There are 6 owner-reported engine complaints for the 2008 Mercury Grand Marquisin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
THE VEHICLE RECENTLY EXPERIENCED TWO SUDDEN ACCELERATION EVENTS IN TWO DAYS 15 MILES APART WHILE DECELERATING AND USING THE BRAKE IN WHAT COULD ONLY BE RELATED TO AN INTERMITTENT FAILURE OF THE ELECTRONIC THROTTLE CONTROL. WHILE ON VACATION DURING A 75 DEG EVENING WITH THE CAR AT OPERATING TEMPERATURE I WAS NAVIGATING SOME S TURNS HIGH ON A BLUFF AT 30MPH. WHILE COMING INTO A CORNER WITH MY FOOT ON THE BRAKE AND SLOWING TO AROUND 20MPH THE CAR SUDDENLY ACCELERATED. I HIT THE BRAKES HARD, TURNED AWAY FROM THE CORNER TO AVOID GOING OVER THE CLIFF AND TURNED OFF THE KEY. ALL THIS HAPPENED IN LESS THEN 5 SECONDS. THE NEXT DAY MID AFTERNOON AFTER DRIVING 20 MILES I WAS LEAVING A PARK AND TRAVELING ON A LEVEL STRAIGHT ROAD AT AROUND 25MPH. COMING UP TO A STOP SIGN I LET OFF THE GAS AND STARTED APPLYING THE BRAKE (LIKE THE DAY BEFORE) AT ABOUT 15MPH THE CAR VIOLENTLY ACCELERATED. I HIT THE BRAKES HARD AGAIN, THE REAR TIRE STARTED SPINNING AND IT PUSHED THE CAR THROUGH THE CROSSWALK PAST THE STOP SIGN AND INTO ONCOMING TRAFFIC BY ABOUT 4FT BEFORE I GOT THE ENGINE SHUT OFF. ONCE AGAIN THIS ALL HAPPENED IN A MATTER OF SECONDS. AFTER A RESTART EVERYTHING WAS NORMAL AGAIN. I DROVE AROUND 250 MI TO GET HOME WITHOUT ANY FURTHER INCIDENT. TWO WEEKS PRIOR TO THESE EVENTS I HAD THE CAR AT THE DEALER TO PROGRAM A NEW TRANSPONDER KEY, RESET THE KEYLESS ENTRY AND TEST THE THROTTLE TO SEE IF THE INITIAL DEADBAND COULD BE ADJUSTED (NO ADJUSTMENT WAS DONE). AFTER THE INCIDENT I RETURNED TO THE DEALER AND THEY SAID THEY HAVE NEVER HEARD OF THIS PROBLEM, THERE ARE NO RECALLS OR TSBS, AND THE ECM WOULD NOT DATALOG ANYTHING SINCE THERE WAS NO TROUBLE LIGHT. THEY SAID THERE WAS NOTHING THEY COULD DO. I CONSIDER THIS UNSATISFACTORY, DEEM IT A MAJOR SAFETY DEFECT AND FORD SHOULD BE REQUIRED TO CORRECT THIS IMMEDIATELY. A QUICK SEARCH REVEALS I AM NOT THE ONLY ONE WHO HAS EXPERIENCE THIS.
WHILE DRIVING UP A SHORT MODERATE GRADE, THE CAR ENGINE SHUT OFF. THE BATTERY (NEARLY NEW) WAS FINE AND THE DASHBOARD LIGHTS WERE DISPLAYED WITH ICONS LIT. THE STEERING WAS AFFECTED AND THE CAR DRIFTED TO A STOP ON A LEVEL SURFACE. I WAS SUCCESSFUL IN RESTARTING THE CAR ON THE FIRST TRY AND THIS INCIDENT HAS NOT RECURRED. I DID NOT MAKE NOTE OF WHAT THE DASHBOARD LIGHTS WERE, AS I WAS MORE INTERESTED IN RESTARTING THE CAR. I DO HAVE A RATHER HEAVY KEY SET (HEAVIER THAN MOST). *TR
MY GRAND MARQUIS LS 2008 PAINT HAVE CRACKED AND FALLING OFF THE HOOD, TOP, AND BACK. IT IS RUSTED ON TOP WERE THE PAINT HAVE PEEL OFF AND NOW ITS STARTING ON THE HOOD. TOOK BACK TO DEALER AND WAS TOLD THAT THE PAINT ON CAR WAS NOT COVER. IT START PEELING TWO MONTH AFTER WE GOT THE CAR DIDN'T HAVE THEM MANY MILES. SO WHAT CAN BE DONE ABOUT MY CAR PEELING PAINT. EVERY TIME YOU WASH THE CAR MORE PAINT COMING OFF. AFTER THAT THE ENGINE COOLING SYSTEM WENT OUT AND THEY TOLD ME THEY ARE RESPONSIBLE. *TR
UNEXPECTED ACCELERATION OF 2008 MERCURY GRAND MARQUIS, WHILE MY FOOT WAS ON THE BRAKE, SLOWING THE VEHICLE. THIS HAPPENED TWICE IN THE PAST 3 DAYS. SECOND INCIDENT OCCURRED OCT. 31, 2008. EACH INCIDENT NEARLY CAUSED MY VEHICLE TO STRIKE ANOTHER VEHICLE. *TR
JUST BOUGHT THE 2008 GRAND MARQUIS, FIRST DAY, RADIO DID NOT WORK, (STILL DOES NOT WORK PROPERLY). TOOK THE CAR IN FOR OIL CHANGE 2500 MILES, ALSO ASKED THEM TO CHECK OUT A NOISE THE CAR WAS MAKING. I WAS JUST INFORMED YESTERDAY I NEED A NEW ENGINE. THEY THE DEALER SAID IT WAS SOMETHING TO DO WITH THE TIMING CHAIN AT FIRST THE REPLACED THAT PART AND STILL HAD THE NOISE. I WILL NEVER OWN A FORD PRODUCT, AND THEY WONDER WHY THEY ARE LOSING MARKET SHARE!!! BY THE WAY, THIS IS MY 9TH GRAND MARQUIS, I JUST TRADED AN 2005 TO GET RID OF IT, IT TOO HAD A NOISE THEY COULD NOT FIX. NOW MY WIFE WILL NOT EVEN DRIVE THIS ONE WHEN WE GET IT BACK FROM THE DEALER. *TR
THE FIRST TIME I CHANGED THE OIL IN MY 2008 MERCURY GRAND MARQUIS WHEN I STARTED THE ENGINE THERE WAS A LOUD MECHANICAL NOISE FOR A FEW SECONDS. I TOOK IT TO THE DEALER AND TOLD HIM TO CHANGE THE OIL AND LISTEN FOR THE NOISE WHICH THEY HEARD AND WAS TOLD ALL 2008 GRAND MARQUIS DO THIS .ALSO I NOTICE THE ENGINE IS NOISY IN THE MORNING WHEN I START IT. I THINK FORD HAS A PROBLEM WITH THESE ENGINES IF THEY ALL DO IT. *TR
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