Transmission jukes ahead while traveling on long distances and short. When I let off of brake pedal it lounges forward. It has gotten worse in 2months time. I brought it to the dealer which in turn told me I must wait for a recall per Ford motor co. I feel this is nonsense being this matter is getting worse!!! What, I have to wait for my vehicle to die before I can get something done about…
2007 Mercury Mountaineer powertrain problems
severe 23 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
23
Recalls
0
Avg fix
$2,500
3crashes
When does it fail?
Of the 23 powertrain complaints filed for the 2007 Mercury Mountaineer, here's the actual mileage breakdown — failures cluster heaviest at 125,000-150,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Powertrain accounts for 28% of all owner complaints filed against this vehicle, across 6 categories tracked.
No new NHTSA powertrain complaint has been filed on this vehicle in over 18 years — the issue may be aging out of the active population.
The failure pattern owners describe
The 2007 Mercury Mountaineer shows a consistent pattern of transmission and shift control failures across 23 complaints. The most recurring issue is the gear shifter locking in Park, forcing owners to manipulate a manual release lever or wait for the vehicle to unstick—one owner pulled the shifter out of Park 24 times before transmission work identified 24 lever-angle modifications and 12 rod-and-pawl modifications already performed by previous repairs.
Transmission slip and jerking dominate the remaining complaints: hard downshifts at stops, violent bucking during acceleration, and surging forward at traffic lights. Several owners report transmission slipping from day one, and dealers have replaced transmissions at 137,000 miles after repeated reprogramming failures. One owner alleges Ford knew of these transmissions' failure by 130,000 miles since 2000 but continued installing them.
Two complaints describe unintended acceleration, including one that crashed into a building at 30,000 miles; another reports complete loss of power on the freeway despite throttle input. A thermostat housing leak causing electrical shorts to the transmission control system appeared in multiple narratives and is referenced as TSB 09-22-15, yet owners say dealers failed to identify the issue as the root cause.
Repair attempts across Ford dealerships and independent shops have been largely unsuccessful—reprogramming, computer updates, and component replacement failed to permanently resolve the drivability problems.
Same Mercury Mountaineer powertrain reports on nearby years: 2005 · 2006
Failure modes owners describe
Shift stuck in Park
Gear shifter becomes mechanically locked in Park and will not move to any other gear position. Owners report needing to use the manual park release lever, or the vehicle sometimes unsticks after rocking or from incline pressure changes. In some cases the shift cable disconnected or the shifter circuit board failed.
When: Occurred repeatedly throughout ownership; as early as 30,000 miles in one report, at 43,236 miles in another, and recurring over multiple months with multiple tows
Symptoms owners cite: Shifter completely stuck and will not move; Shifter moved freely but would not engage any gear; Required multiple towing incidents to diagnose; Intermittent locking requiring manual park release lever to be used
Repairs/costs cited: Gear shifter replaced; shift cable found disconnected; gear shift lever circuit board replaced; some vehicles required multiple repair attempts; shift cable had been modified 12 times and lever angle modified 24 times at transmission shop
Recalls/TSBs owners mention: NHTSA complaint filed; dealership repairs attempted but failures recurred; no recall mentioned
Transmission slip and jerking
Transmission slips gears during driving, produces hard downshifts or upshifts, and causes the vehicle to jerk or lunge unexpectedly. Owners report vibration, hard shifts when stopping or in slow traffic, surging forward at traffic lights, and bucking during acceleration. Some occurred in warm weather; others happened daily.
When: Starting at 9,000 miles through 60,000+ miles; one report noted transmission failure by 130,000 miles; problems worsened over weeks or months
Symptoms owners cite: Transmission slips gears or fails to engage; Hard downshift or upshift when stopping or in slow traffic; Vehicle surges or 'leaps' forward at stop lights; Violent bucking during acceleration in overdrive; Vibration felt while driving at highway speeds; Transmission clunks or hesitates when gas pedal pressed; Jerking or jolting when shifting into Reverse
Repairs/costs cited: Transmission fluid added but problem persisted; technicians unable to duplicate; dealer reprogrammed vehicle but failure worsened; new computer part installed but failure persisted; one owner replaced entire transmission and related parts at 137,000 miles; one dealer told owner to wait for recall
Recalls/TSBs owners mention: One owner reports 'silent recall' alleged by dealership; one TSB 09-22-15 mentioned by owner regarding thermostat housing leak issue; one owner told to file NHTSA complaint; owner advised to wait for recall; no official recall or warranty coverage confirmed in narratives
Unintended acceleration / loss of power control
Vehicle accelerates without driver input or fails to accelerate when commanded. One case involved immediate full acceleration after ignition resulting in crash into building. Another involved loss of power on freeway and multiple occasions where vehicle would not respond to throttle.
When: One incident at 30,000 miles; freeway incident on unknown mileage; problem ongoing in another case
Symptoms owners cite: Vehicle accelerated immediately after start without warning; Vehicle crashed into store after unintended acceleration; Loss of power while driving on freeway; vehicle would not accelerate despite pedal input; Prior brake engagement would cause unexpected acceleration (as reported by same owner); Vehicle would not accelerate in middle of city traffic
Repairs/costs cited: Dealership stated nothing wrong with vehicle when brake acceleration reported; vehicle destroyed by insurance company; throttle position sensor identified by owner as Ford-made part; no repairs documented
Recalls/TSBs owners mention: Dealer stated no defect found; no recall or TSB identified in narrative
Thermostat housing leak causing electrical/transmission malfunction
Coolant leak from thermostat housing enters electrical system, shorting out wiring and causing transmission control or engine control issues that mimic transmission failure. Owners report sudden inability to shift or accelerate, high RPM at idle, and poor shifting response.
When: Occurred during driving in rush-hour traffic and on highway; timing in vehicle ownership not specified for most cases
Symptoms owners cite: Thermostat housing visibly leaking; Electrical system shorted out by coolant leak; Vehicle would not accelerate or shift properly after leak; High idle RPM; Poor shift quality; Appeared to mimic transmission failure but was electrical
Repairs/costs cited: Thermostat housing replaced; associated wiring repaired (one owner cited 'very expensive wiring issues'); no cost specifics provided
Recalls/TSBs owners mention: TSB 09-22-15 issued for thermostat housing leak issue (per owner report); issue identified as common in 2007-2009 Mountaineers and Explorers
Hard transmission shifts and transmission noise
Transmission produces clunking or grinding noises and shifts harshly at low speeds or when downshifting. Issues persist despite multiple dealer attempts to reprogram or repair.
When: Starting at 9,000 miles and continuing; one case had ongoing problem since 1997 (purchase year); became worse over time
Symptoms owners cite: Transmission clunks or hard shifts when slowing down to a stop; Grinding or clunking noise when downshifting at low speeds (15 MPH); Transmission slip continuing after repair attempts; Hesitation when accelerating
Repairs/costs cited: Dealer reprogrammed vehicle twice; new computer module installed; transmission specialist consulted; megatronics review initiated; no successful repair documented; owner noted problem is common in Ford SUVs per internet blogs
Recalls/TSBs owners mention: Multiple dealer reprogramming attempts; no recall or TSB referenced in narrative
Intermittent electrical system failures affecting drivetrain and dashboard
Dashboard gauges and instrument panel pixels illuminate or turn off intermittently. Power seat operates freely while vehicle is in motion. Headlights fail intermittently. These failures correct themselves after engine restart but recur unpredictably.
When: At approximately 46,000 miles
Symptoms owners cite: Instrument panel and gauges illuminate intermittently due to defective pixels; Headlights fail intermittently; Power seat moves backward and forward freely during driving; All failures self-correct upon engine restart; Failures recur without warning
Repairs/costs cited: Vehicle not diagnosed or repaired; technician unable to duplicate the problem at dealership
Recalls/TSBs owners mention: Manufacturer notified but no response or action documented
Shift lever mechanical failure / Inability to shift out of Park
Shift lever becomes stuck or locked and cannot be moved from Park position. Manual park release lever must be used. In some cases depressing the lever button and applying brake do not release Park.
When: Various mileages; one at 78,000 miles; one at 19,000 miles (under warranty)
Symptoms owners cite: Shifter will not respond to lever input; Shifter button and brake pedal depression insufficient to release Park; Manual park release lever must be used to escape Park; Gears shift to wrong positions after release (e.g., Reverse becomes Park, Neutral becomes Reverse)
Repairs/costs cited: Unknown transmission part needed replacement per independent mechanic; one owner told to use manual park release lever each time; $500 quoted by dealer for part only; not repaired in some cases due to cost
Recalls/TSBs owners mention: Extended warranty did not cover shift lock issue; manufacturer advised filing NHTSA complaint; no recall identified
Synthesized from 23 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 7 most recent
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…
2007 mercury mountaineer. Consumer writes in regards to acceleration and console lighting issues and problems with back windshield wipers. *smd
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…
Tl*the contact owns a 2007 mercury mountaineer. The transmission made noises when downshifting at 15 MPH or when starting the vehicle. The dealer reprogrammed the vehicle. The contact took the vehicle home, but the failure worsened. The transmission continued to slip. She returned to the dealer and left the vehicle there for a few days. A new computer part was placed in the vehicle, but the…
Apparently there have been a lot of issues with the thermostat housing leaking fluid into the electrical system causing it to short out. I was driving, went to take off in rush hour traffic and they vehicle wouldn't go because the leak and ruined a part of the electrical system and the gears would shift. It was almost like the transmission had gone out. I have read several accounts where this…
Tl*the 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…
Had powertrain trouble with your 2007 Mercury Mountaineer?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2007 Mercury Mountaineer?
It's a meaningful issue. 23 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Across the 20 complaints that reported odometer mileage, most powertrain failures cluster between 43,236 and 130,000 miles, with the median around 78,000. A quarter of owners report trouble before 43,236; a quarter make it past 130,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2007/Mercury/Mountaineer.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.