Most common 2004 Mercury Mountaineer problems
Share of the 210 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mercury Mountaineer complaints by model year
Best Mountaineer years: 2009, 2010, 2001. Years to avoid: 2002, 1997, 1998, 2004, 1999. Compare all years →
NHTSA defect investigations
Federal safety investigators have looked into 3 possible defects involving the 2004 Mercury Mountaineer:
Rear liftgate glass hatch failure
This investigation was opened on June 23, 2008, based on 34 complaints involving eight injuries in which the rear liftgate glass hatch on model year 2004 Ford explorers or Mercury mountaineers broke off and fell, usually while individuals were operating the glass hatch or loading or unloading items from the rear of the vehicle.Ford conducted recall 04v-442 in 2004 to address similar problems on model year 2002 and…
Vehicle Rollaway Allegations
This investigation is being closed based on several considerations.By the most inclusive counting of all alleged rollaway incidents (i.e., counting all alleged rollaway incidents and assuming a singular failure mechanism), the incident rate is low, however during EA09-013, ODI identified a number of different failure mechanisms in 180 incidents related to the alleged defect.The highest rate for any particular…
Spark plug ejection from cylinder head
On September 6, 2005, odi received a petition requesting that the agency investigate allegations of engine spark plug ejection in certain model year 1997 through 2004 Ford vehicles with triton v-8 and v-10 engines.odi received a total of 474 non-duplicative complaints on the subject vehicles where the complainant, or the dealer repairing the vehicle, reported that a spark plug detached from the cylinder and/or…
What 2004 Mercury Mountaineer owners say
Body & structure all 79 →
Rear tailgate window hinge broke while having the window only open and putting away groceries. Upon closing the window, the right hinge broke causing the window to almost fall off of the car. I attempted, with assistance from others in the parking lot, to push the window back into the frame and have it lock at the center latch. The latch is no longer engaged and I have attempted to push on the window to connect with the latch. I am not strong enough to do so. The window is at a point where it could fall off of my car. There was a recall on this part for 2000-2003 vehicles of this make and model. Ford is not carrying over the recall to 2004 stating the defect is not the same (with the details) as the recall itself. It is still the same defective part! I am of short stature and do not have the strength to push the window the 1" or so to get it into the frame to lock successfully. …
The rear liftgate cracked near the Mercury emblem. This occurred about two years after purchasing the vehicle new. I took it to two different Ford dealerships and was told by both the Ford would not fix this problem on the 2004. One stated the 2003 model had the same problem, but that Ford repaired those. I did not receive a response to my email I sent to Ford. This is a substantial expense to the owners of this vehicle. If you look around you can tell if you are behind a 2004 explorer or mountianeer, they all will have at least one crack around the emblem.
Transmission & drivetrain all 64 →
This vehicle is has a power train problem from day one with the 5R55S/W transmission and AWD transfer case. I purchased this vehicle where it stranded my family over 200 miles from home and it's a non running car. This vehicle should have been removed from being sold with this defect and crushed! I will never buy a FoundOnRoad Dead ford pos ever. The transmission went into neutral with out any notice. To repair the faulty drive train I will cost me aprox $2400.00 mileage 152,000 third time the drive train has been worked on.. There tranmissions were failing in a little as 50,000 miles.
Our vehicle was purchased in June 2008 at dealership nearby. We were driving home and there was a grinding and popping sound in the rearend of the vehicle. It was me , my husband, 3 mth old and 2 yr old occupying the car. My husband got out of the car and stated to get the babies out of the car in a hurry it was on fire. We got the babies out and ran in to call 911 and the fire dept. The fire was contained and took to a local garage at that time I contacted my auto insurance to see if this was something that would be covered. They sent an auto adjuster out to look at it. Our insurance did help to repair the rear differential. The rear differential had got so hot it exploded causing the fire. Then after the car was repaired we began to have problems again at that time I contacted Ford motor company. …
Speed control & acceleration all 21 →
Vehicle speed control: while preparing to back up, before shifting, vehicle jumped, and then suddenly accelerated forward, brakes were applied but vehicle wouldn't stop and engine was roaring as if the accelerator was stuck. Vehicle went airborne over an embankment, through a lawn, hit a rock/debris area, tire blew before hitting curve, landed on right rim, was then able to put vehicle in park. Vehicle towed away, dealership currently states nothing is wrong with the vehicle. Help!!
My 2004 Mercury Mountaineer accelerated on it's own as I was pulling into a parking space. The vehicle made a roaring sound. My foot never left the brake pedal and I could not stop it. I jumped the curb, went over a grassy area, over the sidewalk and did not stop until I hit a concrete building at approximately 25-30 miles per hour. It caused significant damage to the building and to the car. Airbag did not deploy. I have had the body damage repaired and my auto insurance has paid over $3,000 for that. My husband took it to our nearest Ford dealer where they ran a diagnostic and it showed an electronic malfunction. They said the throttle body assembly needs replacing. The technician did not give us a print-out and said he couldn't find it when we checked back later. We contacted Ford motor company to see if they would pay for the replacement because our insurance would not. …
2004 Mercury Mountaineer engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 4.0L 6-cyl | 5-speed automatic | RWD | 14 / 20 / 16 |
| 4.6L 8-cyl | 5-speed automatic | RWD | 13 / 18 / 15 |
| 4.6L 8-cyl | 5-speed automatic | 4WD/AWD | 13 / 18 / 15 |
| 4.0L 6-cyl | 5-speed automatic | 4WD/AWD | 13 / 18 / 15 |
EPA ratings. Class: SUV.
Frequently asked questions
Is the 2004 Mercury Mountaineer a good car?
Based on 210 owner complaints filed with NHTSA, the 2004 Mountaineer rates use caution: 1.6× as many complaints as a typical year of the Mountaineer at the same age. It is one of the Mountaineer years we suggest avoiding. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2004 Mercury Mountaineer?
The body & structure — 79 complaints, 38% of all complaints for this model year, most often about body. Next are the transmission & drivetrain (64) and speed control & acceleration (21).
How many recalls does the 2004 Mercury Mountaineer have?
NHTSA lists no recalls for the 2004 Mercury Mountaineer. You can still confirm with your VIN using our VIN recall check.
What are the best and worst years of the Mercury Mountaineer?
The best years by complaints, compared at the same age, are 2009, 2010 and 2001. Years to avoid or approach with caution: 2002, 1997, 1998, 2004 and 1999. See the full Mercury Mountaineer years comparison.
At what mileage do 2004 Mercury Mountaineer problems happen?
The median mileage reported in complaints is about 68,000 miles; 34% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.