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really awful
Crashes / Fires:
4 / 0
Injuries / Deaths:
2 / 0
Average Mileage:
36,406 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2004 Mercury Grand Marquis engine problems

engine problem

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2004 Mercury Grand Marquis Owner Comments

problem #16

Jun 022015

Grand Marquis

  • 80,000 miles


Vehicle headlights work intermittently. Cruse control does not reset or turn on when supposed to. This is also an intermittent problem, sometimes resetting, and sometimes not. Headlights would sometimes not turn on when driving unless pulling turn signal arm toward steering wheel and holding. High beams only would work.

- Phoenix, AZ, USA

problem #15

Jul 172015

Grand Marquis 8-cyl

  • Automatic transmission
  • 58,000 miles
The contact owns a 2004 Mercury Grand Marquis. While the vehicle was coming to a stop, the contact depressed the brake pedal and the speed and rpms increased without warning. The contact continued to depress the brake pedal; however, the vehicle failed to respond. The contact powered the vehicle off and noticed blue smoke emitting from the rear of the vehicle. The vehicle was taken to the dealer, but the failure was unable to be determined. The vehicle was not repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 58,000. MA 09/25 updated 12/05/2017

- St. Charles, MO, USA

problem #14

May 112011

Grand Marquis

  • 50,000 miles
The contact owns a 2004 Mercury Grand Marquis. While driving approximately 65 mph, the vehicles speed increased. When the brake pedal was engaged, the vehicle began to reduce speed. The contact maneuvered onto the emergency lane and turned the vehicle off. After restarting the vehicle, it began to function normally. The failure occurred three times. The vehicle was taken to an authorized dealer for diagnostic testing and the they were unable to diagnose the failure. The manufacturer was not made aware of the defect. The approximate failure mileage was 50,000. The VIN was unavailable.

- St. Cloud, FL, USA

problem #13

Jun 012010

Grand Marquis

  • 50,000 miles


The contact owns a 2004 Mercury marquis. The contact stated that while driving 20 mph with the brakes engaged, the vehicle suddenly accelerated. The contact stated that in order to stop the vehicle, he had to shift into neutral and shut the engine off. The vehicle was not taken to a dealer to have the failure diagnosed. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure mileage was 50,000 and the current mileage was 67,000.

- Affton , MO, USA

problem #12

Jun 292011

Grand Marquis

  • 27,800 miles
The contact owns a 2004 Mercury Grand Marquis. The contact stated that while in reverse, the vehicle surged backwards until heavy pressure was applied to the brakes. The vehicle was taken to an authorized dealer where the contact was informed that the failure was normal. The vehicle was not repaired. The failure mileage was 27,800.

- Tewksbury, MA, USA

problem #11

May 312011

Grand Marquis 8-cyl

  • 71,000 miles
I own a 2004 Mercury Grand Marquis ls that unexpectedly goes into unintended acceleration when slowing down or stopping vehicle. I never know when the unintended acceleration will occur. First noticed problem at about 24000 till now at 71000 miles. The problem occurs usually in a line of traffic as I am slowing down or slowing down to stop at a stop sign or traffic light. Or parking the vehicle. Suddenly the engine starts racing and sometimes the vehicle will jump forward rapidly (sudden unintended acceleration). I have to apply the brakes rapidly and with extreme pressure to keep the vehicle from hitting the vehicle in front of me or to keep from running a traffic light or stop sign. Most of the time when the engine races and I apply the brakes the rear wheels will continue to spin at a high rate even to the point of causing the rubber on the tires to smoke and still try to push me forward. After applying the brakes I must turn off the engine using the key to stop the unintended acceleration. This is a serious safety problem. I noticed the problem not long after purchasing the car and reported it to the dealer dub herring Ford in picayune, Ms. While the car was still under warranty. They didn't do anything to check or fix the problem. They seemed not to worry or be concerned about this problem! I reported the problem several times to the dealer with no success. I then reported it to the Ford Motor Company several times and they referred me to the dealer which didn't do anything to fix the problem to start with. I then took the car to an independent repair shop and they tried to find out from the dealer and Ford co. If there was a recall or notation or fix for the problem. The independent shop said the dealers and Ford co. Wouldn't give him any information concerning the problem. They asked me to contact Ford Motor Co. And see if I could get any response for a fix or repair and got no help from them. I am lodging a formal complaint against Ford and the dealer.

- Mississippi, MS, USA

problem #10

Apr 142010

Grand Marquis

  • 57,692 miles


Three times my 2004 Mercury marquis has had shown "prius like" problems. Once in dry summer, then twice in winter in the pacific nw.the last time I was into the intersection when I slammed on my parking brake to stop the car but the motor was still racing.

- Brookings, OR, USA

problem #9

Feb 152009

Grand Marquis 8-cyl

  • 88,000 miles
Unintended acceleration: Last year (Feb 2009) my 2004 Mercury Grand Marquis had an unintended acceleration which I (weight lifter) could barely control and I almost crashed into 2-cars. I also had to have the brakes replaced due to severe braking required to stop the car due to the unintended acceleration I used a reliable mechanic (highly rated by the state of MA) as the local Ford dealer shops are over-priced and unreliable. No diagnostic codes showed-up at the shop after the problem, but I would not have my wife drive this car" the car is well maintained and I had a previous Grand Marquis, so I know the car better than most. Have you heard about this problem and is there a recall" Ford was contacted on Feb 23 2010, via their protal, and indicated that there was no problem or recall, and suggested that I go to their dealer (did not go as I have no need for bs). I informed my local mechanic that the car went into overdrive and I had to drive over the curb (brake to floor to stop it).L burned out the brakes but no one died. There was no diagnostic codes that showed a braking or other electronic problem.

- Acton, MA, USA

problem #8

Mar 042005

Grand Marquis 8-cyl

  • Automatic transmission
  • 16,890 miles
: the contact stated while approaching a stop under normal braking, the vehicles engine revs and surges forward. The brake pedal must be depressed to the floor to stop the vehicle. This happened 5 times and the vehicle was inspected by the dealer however; the problem could not be duplicated. The vehicle was driven over 6,000 miles when the problem returned. It was taken back to the dealer for service and again the dealer was unable to duplicate the problem. The consumer believed there is a problem with the transmission. Updated 04/06/06.

- Cincinnati, OH, USA

problem #7

Dec 302005

Grand Marquis 8-cyl

  • Automatic transmission
  • 25,000 miles
: the consumer stated while depressing the brake pedal the vehicle accelerated. The vehicle was taken to the dealership the first time; a diagnostic test was performed on the vehicle and they were unable to duplicate the problem. The vehicle was driven for a period of time and the acceleration problem continued to persist. Updated 02/24/06.

- Fort Myers, FL, USA

problem #6

Aug 012005

Grand Marquis 8-cyl

  • Automatic transmission
  • miles


2004 Mercury Grand Marquis accelerated at full speed when consumer barely touched the accelerator pedal. This resulted in the vehicle crashing through the back wall of the consumer's garage.

- Lemont, IL, USA

problem #5

Jul 302005

Grand Marquis 8-cyl

  • Automatic transmission
  • 27,800 miles
My wife was driving our 2004 Mercury Grand Marquis (pre-certified, bought off the showroom floor August 2004); our three teenage foster care children and I were passengers. Our marquis entered the parking lot of convenience store so that we could install air in left front tire. We did a U-turn in parking lot to proceed to air compressor. With her right foot on brake pedal, my wife steered the car through the U-turn, heading toward air compressor. Suddenly, without any warning, the car accelerated uncontrollably. The brake would not work - brake pedal was pushed all the way down; car continued to accelerate and traveled over a large concrete barrier and crashed into building. The car could not be steered while car sped forward. The air bags did not deploy. We were wearing our seat belts and shoulder harnesses. Thankfully, the auto hit the building instead of the gasoline pumps in parking lot. After crashing into building, the engine continued to accelerate or "rev" at high rate. A lady who was pumping gas into her car rushed over to assist us. She insisted that my wife keep her foot on brake pedal and assisted in getting the driver's door open and instructing for my wife to avert her face and inch over in seat toward door after releasing the shoulder harness/seat belt. I was able to get the car in park and turn ignition off. My wife was transported by ambulance to er for treatment of injuries. Highway patrol officer made accident report. Auto was towed to private repair facility for evaluation.

- Pensacola, FL, USA

problem #4

Jul 302005

Grand Marquis 8-cyl

  • Automatic transmission
  • 28,071 miles
The vehicel accelerated suddenly and the brakes could not stop it. While in a parking lot to put air in the tires the vehicle just took off and crashed into a building. This happened July 30, 2005 the consumer is getting ready to contact Ford.

- Pennisacola , FL, USA

problem #3

Nov 012004

Grand Marquis

  • miles
There was problem with the gear shift or transmission, shift lever moved forward and shifted into reverse without my touch. The vehicle gets hung-up in neutral. From drive or reverse into park there was a metal to metal interference evident. The gear would stick and required 2 to 3 minutes of jiggling back and forth with pressure to get into park, other times when in park and had the engine running, the key would shut down the engine, but could not removed without putting more pressure on the lever into park. On another occasion the vehicle drove backwards about 4 ft. Before the consumer could put his foot into the vehicle and onto the brake. This was an intermittent problem.

- Linthicum, MD, USA

problem #2

Oct 102004

Grand Marquis 8-cyl

  • Automatic transmission
  • 2,235 miles
When the consumer attempted to come to a stop, the vehicle accelerated into a building. The vehicle was towed. The dealer could not find anything wrong. The consumer found several similar incidents.

- Bay Shore, NY, USA

problem #1

Mar 222004

Grand Marquis

  • miles
Consumer stated that while driving came to a red light and vehicle took off. The more he applied the brakes the faster vehicle went. He and his wife narrowly escaped a collision. Consumer took feet off the brakes, and placed the vehicle in neutral, which caused it to slow down. Then, he coasted to the side of the road. Consumer called the dealer, who told him to call a tow truck. Consumer had vehicle towed to the dealer. After inspecting the vehicle dealer told consumer that they never heard of this problem with this type of vehicle. However, he was told by another dealer that it might have been the cruise control kicking in when it was not suppose to. Consumer was very concerned because he and his wife were nearly killed.

- Fairhaven, MA, USA

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