Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2007 Mercury Mountaineer owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2007 Mercury Mountaineer. The contact stated that after shifting the transmission from park(P) to reverse(R), the vehicle failed to respond. The contact removed and reinserted the fob key in the ignition to correct the failure. The vehicle was taken to an independent mechanic, who diagnosed that an unknown transmission part needed to be replaced. The vehicle was not repaired. The mechanic instructed the contact to pull the park release lever each time to shift the vehicle out of park (P). The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The failure mileage was approximately 78,000.
My 2007 Mercury Mountaineer never had any problems until recently, thought it was the transmission because of the way it drove. Took it to the mechanic and got transmission fluid put in but the problems remained the same and was told the transmission was fine. My thermostat housing unit was leaking (this is very common with these cars and very dangerous, needs immediate attention!) and had caused very expensive wiring issues. Almost acts exactly like the transmission is going out - RPM's are way too high, the vehicle would not accelerate in the middle of city traffic, the car jumped at a stoplight and caused me to hit the car in front of me, and it doesn't shift properly. Problems occurred out of nowhere and are too dangerous to be ignored but very expensive to be fixed. Its very common and should be recalled before someone gets seriously injured!!!!
I had to replace the transmission and some other related parts in my vehicle and I was informed by a dealership that there was a "silent recall" on this transmission and that even though Ford motor company was aware of the issues as early as 2000 they continue to install them in vehicles. If you look online you will see quite a number of complaints on this transmission. I feel since Ford knowingly kept using these transmissions and was well aware of their possible failure when they reached 130,000 miles that they should be responsible for at least a portion of he costs if indeed, not all of the cost of replacement. What happens when a car company puts out a silent recall? Do I have any rights? I have already sent a certified letter to Ford motor customer relations in dearborn, mi and I have a signed receipt that they accepted my letter but they have not bothered to contact me at all. …
Tl contact owns a 2007 Mercury Mountaineer. Immediately after the vehicle was turned on without warning, it accelerated and crashed into a store. The police gave her a ticket for careless driving. The vehicle was towed to an authorized dealer. She was not informed of the repairs that were made to the vehicle. The contact has had problems with the vehicle since she purchased it. Prior to the failure, whenever she engaged the brake pedal the vehicle accelerated without warning; however, the dealer stated that there was nothing wrong with the vehicle. The vehicle was destroyed per the insurance company. The contact was always concerned about the safety risk and defect in the vehicle . The failure and current mileages were 30000. Updated 11/04/09. The consumer stated the vehicle made a noise when the gear was placed in reverse. Updated 11/05/09
I turn my 2007 Mountaineer AWD on and it accelerates, so I let it stop idling high and if it doesn't totally shut off I then proceed to put my truck either in drive or reverse and it jerks very hard. I have already hit my garage because I was not able to stop the vehicle. I already took it to Ford and they told me that the engine light is not on so they can't do anything about it. They little wrench symbol is on though. I am so scared that I am going to end up killing someone. I wish I could afford to not drive my truck around but it is my only transportation. I have to drive my 4 kids with me and it concerns me. Some one please help, from what I see is another Toyota disaster waiting to happen.
Tl* the contact owns a 2007 Mercury Mountaineer. While driving various speeds, the vehicle would jump and jerk. The vehicle was taken to an independent mechanic and it was diagnosed that the transmission failed. The dealer and manufacturer were not made aware of the failure. The vehicle was not repaired. The failure mileage was 60,000. Updated 9/21/18
While driving my seat will randomly move back and forth as if I took the keys out. Thought something was wrong with my transmission but after having the garage put transmission fluid in it still feels like the transmission is messed up even though the garage says the transmission is fine.
Seat moved back for "easy exit" all vehicle components shut off and vehicle brakes locked up in the road then cut back on by itself and transmission jerked into gear like someone rear ended us! Very scary and unsafe with my 10 month old in the vehicle!
Had to replace transmission completely at 137,000 miles. There's been a lot of complaints about these transmissions at this mileage and Ford should be responsible for some of the cost. This is ridiculous.
Tl* the contact owns a 2007 Mercury Mountaineer. The contact was driving approximately 50 MPH when a vibration was felt and the transmission began to slip gears. The failure appeared to occur more frequently in warm weather temperatures. The vehicle was taken to an authorized dealer but the technician was unable to duplicate the problem. In addition, the instrument panel and gauges would illuminate intermittently as a result of defective pixels. The front driver's side power seat would move backward and forward freely while the vehicle was in motion. The contact would shut off the vehicle and once restarted, the failures would correct independently until later recurring without warning. In addition, the headlights failed intermittently. The vehicle was not diagnosed or repaired for the failures. The manufacturer was notified of the defects. The approximate failure mileage was 46,000.
Transmission complaints in other Mountaineer years
Frequently asked questions
How common are transmission problems on the 2007 Mercury Mountaineer?
NHTSA has 25 complaints about the transmission & drivetrain of the 2007 Mercury Mountaineer, 31% of the model year's 81 complaints. The component named most often is automatic transmission (4 mentions).
Is there a recall for 2007 Mercury Mountaineer transmission problems?
No. NHTSA lists no transmission & drivetrain recall for the 2007 Mercury Mountaineer. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2007 Mercury Mountaineer transmission problems start?
Half of the complaints with a recorded mileage happened before about 78,000 miles, and 14% before 25,000 miles.
Is it dangerous?
Owners linked 3 crashes, 0 fires and 0 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
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.