2005 Mercury Grand Marquis Engine Problems
- Complaints
- 5about this part
- Share
- 1%of 488 total for the year
- Median mileage
- 59,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 5 complaints about the engine of the 2005 Mercury Grand Marquis, 1% of the 488 complaints for this model year. Where a mileage was given, the median is 59,000 miles. 1 a fire, 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.
“When i hit the brake pedal,4 times in past month car accelerated briefly then quit. no warning signs no one can tell me what's wrong i read there was a class action lawsuit file years ago for this problem.”
NHTSA complaint #11579479, filed 2024-03“The contact owns a 2005 Mercury Grand Marquis. While driving 45 MPH, the contact attempted to brake, but the vehicle accelerated. The contact shifted the transmission into neutral and the vehicle stopped. The engine continued to rev for awhile and then the rpms slowed down to a normal level. The contact stated that the symptoms disappeared on their own and the vehicle operated without any failures since. The manufacturer stated that there was no recall for the failure. The failure mileage was 79,000.”
NHTSA complaint #11210796, filed 2019-05, 79,000 milesRelated service bulletins
- 10109070Sep 21, 2016The Powertrain Control/Emissions Diagnosis (PC/ED) manual has been revised for diagnosing electronic throttle bodies (ETBs). The ETC_ACT and ETC_DSD PIDs should not used to…
- 10045340Jul 10, 2012Ford/lincoln/mercury: if battery was disconnected or dead, vehicles/trucks may experience hard starts and engine idle rpm fluctuation and exhibit diagnostic trouble codes (dtcs)…
Engine: 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 2005 Mercury Grand Marquis
293 complaintsElectrical system
75 complaintsAir bags
67 complaintsVehicle speed control
39 complaintsSeat belts
36 complaintsSteering
20 complaintsBrakes
18 complaintsBody and structure
11 complaintsVisibility (wipers, defrost, mirrors)
11 complaintsOther or unknown
10 complaintsEngine cooling
9 complaintsTires
8 complaints
← All problems reported for the 2005 Mercury Grand Marquis
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Nov 1, 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