ON THREE OCCASIONS WHEN SHIFTING FROM PARK TO REVERSE THE ENGINE SPED UP (ACCELERATED DRASTICALLY) CAUSING THE WHEELS TO SPIN AND ONLY BY QUICK APPLICATION OF THE BRAKE WAS AN INCIDENT AVOIDED. I DROVE INTO A PARKING SPACE, PUT THE CAR IN PARK, THEN NOT SATISFIED WITH THE POSITION I ATTEMPTED TO BACK UP, THAT'S WHEN THE CAR ACCELERATED. *JB
2005 Mercury Grand Marquis engine problems
severe 8 complaints filed with NHTSA · avg repair $3,100
Complaints
8
Recalls
0
Crashes
2
Avg fix
$3,100
What owners are reporting 3 most recent
ROUGH ENGINE IDLE, DEALER REPS SAY "ALL THE NEW ONES DO IT", "IT'S NORMAL". I HAVE ASKED THEM ABOUT IT ON SEVERAL OCCASIONS SINCE PURCHASING THE CAR. MY 2005 MARQUIS DOES NOT GET NEARLY THE GOOD GAS MILEAGE THE 2001 MARQUIS DID WITH THE SAME ENGINE. THE DEALER TOLD ME "YOU CAN'T COMPARE CARS". *NM
ROUGH ENGINE IDLE, DEALER REPS SAY 'ALL THE NEW ONES DO IT', 'IT'S NORMAL'. I'VE ASKED THEM ABOUT IT ON SEVERAL OCCASIONS SINCE PURCHASING THE CAR. NOT NEARLY AS GOOD GAS MILEAGE AS OUR 2001 GRAND MARQUIS GOT, WAS TOLD BY THE DEALER, "YOU CAN'T COMPARE CARS'. *NM
Common questions
How serious is the engine problem on the 2005 Mercury Grand Marquis?
It's a meaningful issue. 8 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $3,100.
At what mileage does the engine typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Other problem areas on this vehicle
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Severity ratings are derived from reported crashes, fires, injuries, and fatalities.
Repair cost estimates are independent-shop national averages and may differ in your area.
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