Which parts fail
Components named in complaints (seat frames, recliners, heated seats and seat tracks).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2008 Mercury Mountaineer owners, lightly cleaned up (personal details are redacted by NHTSA).
While driving on a long trip, without warning, the memory seats change seat setting and went back fully as if I shut the vehicle off, this happened several times while I was driving without my assistance. I finally realized that when I touched the keys in the ignition, the seat went back to its original setting. When this occurred I was unable to reach brake and accelerator pedals which could have caused a fatal accident to occur. If this happened at a time that I needed to apply the brakes, I would not be able to and there would have been no way for me to stop. I took my vehicle to an authorized dealer who replaced the ignition. On 6/6/2012 the same thing happened again (mileage 60774), this time I struck the car in front of me, it was a good thing it happened while I was in traffic, and neither vehicle sustained damage. …
Defective ignition. When driving, if you bump the key (or attached keychain), all interior lights will come on, and the drivers seat will retract all the way back into the "easy entry/exit" position, making it impossible for a shorter person to reach the brake or gas pedal. Sometimes during this event, the car will stall. This is very dangerous, and the internet is full of people having this identical issue. Why hasn't this been recalled yet?!? People are paying for a new ignition tumbler, but before long it starts happening to the replacement tumbler as well. Http://www.carcomplaints.com/Mercury/Mountaineer/2008/accessories-interior/seats.shtml
I also have the same issue with the ignition causing the seats to move the easy exit position. This happens constantly while driving and is very unsafe. The interior lights come on as if the key was turned off and removed from the ignition, also causing the seat to move the exit position. When this happens, I am unable to reach the pedals and scramble to correct the issue. I see where this is happening to quite a few other owners. Something needs to be done before someone is seriously hurt or killed.
When I am driving the car the seat will move back on it's own volition into exit position. This happens when it goes over a bump or if the key is jiggled in the ignition. It happened in multiple situations last week. Very frightening as I have to scramble to reach the brake and also move the seat back into position. I have turned off the easy exit option so this has stopped it but it upsets me that I no longer have a feature that I paid for.
After approximately 90,000 miles the dome lights turned on and automatic seats move back while driving. This issue persists and often occurs several times. There are several complaints of this issue found online. It is not due to a heavy key chain as I only have the fob and key attacked. This is a safety issue as the seats pull the driver away from the pedals and steering wheel. Investigate! Recall!
The seat while driving automatically moves back from the brake pedal which causes problems stopping the vehicle. The seat then moves you forward pressing your foot against the gas pedal causing you to speed up. It is a random issue and you are unaware while driving when it will occur. This can cause a serious accident to someone or someone's property and injury to the vehicle occupants.
Tl* the contact owns a 2008 Mercury Mountaineer. While driving 30 MPH, the front driver's seat automatically retracted backwards. The failure recurred on numerous occasions. Also, the interior lighting illuminated on its own. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was 135,000.
While driving the vehicle the interior light turns on and the seat moves back into the park position. This is a safety issue as it is difficult to reach the pedal/brake and it happens without notice. There is no rhyme or reason to this problem. I have seen multiple posts regarding this issue and don't see how it cannot be a recall for safety reasons
Tl* the contact owns a 2008 Mercury Mountaineer. While driving various speeds, the driver seat moved independently. The failure recurred four times. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 150,000.
While driving, driver seat moves forwards or backwards. Not the first time. When vehicle was purchased it happened and we brought vehicle to shop and module was replaced, now this issue is happening again causing me not able to reach brake or accelerator pedals.
Seat complaints in other Mountaineer years
Frequently asked questions
How common are seat problems on the 2008 Mercury Mountaineer?
NHTSA has 54 complaints about the seats of the 2008 Mercury Mountaineer, 56% of the model year's 96 complaints. The component named most often is front assembly › power adjust (2 mentions).
Is there a recall for 2008 Mercury Mountaineer seat problems?
No. NHTSA lists no seats recall for the 2008 Mercury Mountaineer, though it has 1 recall for other components. 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 2008 Mercury Mountaineer seat problems start?
Half of the complaints with a recorded mileage happened before about 65,000 miles, and 12% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to seats 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.