2003 Mercury Grand Marquis Engine Problems
- Complaints
- 5about this part
- Share
- 1%of 362 total for the year
- Median mileage
- 166,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 5 complaints about the engine of the 2003 Mercury Grand Marquis, 1% of the 362 complaints for this model year. Where a mileage was given, the median is 166,000 miles. 1 of these say a crash was involved, according to the filers.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“Last fall, this car starting making creeking and humming noises in the engine. The humming noise would go away after about a minute but not the squeaks and creeks as you drive it. In the winter, there were areas of yellow-green liquid on our garage floor on a few occasions. I took the vehicle in for the headlight recall, and I was told there was a cracked manifold, and a belt problem which was causing the antifreeze leak. When I searched for recalls, I noticed a previous recall for years 1996-2001 for the same problem. …”
NHTSA complaint #10994983, filed 2017-06, 147,000 miles“I started Mercury with foot on break like normal. Shifted into reverse. Car accelerated backwards at full speed. Brakes did not stop car. Attempted to shift into neutral but went into drive instead. Car accelerated forward at full speed with my foot still on break. Car hit metal post and tree knocking them down and dragging the tree 50 to 60 feet before stopping with my foot still on the break. Car had stopped accelerating. I turned off the ignition. This unintended acceleration had happened before. Two different dealers attempted to fix the problem. …”
NHTSA complaint #11502872, filed 2023-01“The contact owns a 2003 Mercury Grand Marquis. The contact stated while driving approximately 70 MPH, the vehicle started losing motive power. The contact stated that the vehicle had shifted to LIMP Mode and was almost side swiped by a tractor trailer. The contact stated that the check engine warning light was illuminated. The contact had not taken the vehicle to a local dealer. The vehicle had been towed to an independent mechanic; however, the vehicle was not diagnosed or repaired. The contact stated that the failure was intermittent at first but became a recurring failure. …”
NHTSA complaint #11524458, filed 2023-05, 240,000 miles“The contact owns a 2003 Mercury Grand Marquis. The contact stated that there was an abnormal noise coming from the engine and the check engine warning indicator illuminated. The vehicle was taken to an independent mechanic where it was diagnosed that the number two cylinder spark plug misfired and the head of the motor needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 178,000.”
NHTSA complaint #10825264, filed 2016-02, 178,000 milesEngine: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2010 | 1 | 4% |
| 2009 | 2 | 8% |
| 2008 | 4 | 5% |
| 2007 | 4 | 4% |
| 2006 | 8 | 6% |
| 2005 | 5 | 1% |
| 2004 | 4 | 1% |
| 2003 | 5 | 1% |
| 2002 | 2 | 3% |
| 2001 | 9 | 6% |
| 2000 | 8 | 5% |
| 1999 | 7 | 4% |
| 1998 | 3 | 2% |
| 1997 | 2 | 1% |
| 1996 | 1 | 0% |
| 1994 | 1 | 1% |
| 1990 | 1 | 2% |
| 1985 | 1 | 5% |
Other parts of the 2003 Mercury Grand Marquis
207 complaintsElectrical system
51 complaintsSteering
28 complaintsSuspension
28 complaintsVehicle speed control
27 complaintsEngine cooling
13 complaintsTransmission and drivetrain
12 complaintsAir bags
11 complaintsFuel system
10 complaintsVisibility (wipers, defrost, mirrors)
10 complaintsWheels
10 complaintsBody and structure
9 complaints
← All problems reported for the 2003 Mercury Grand Marquis
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology