2010 Mercury Mountaineer Engine Problems
- Complaints
- 3about this part
- Share
- 23%of 13 total for the year
- Median mileage
- 55,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 3 complaints about the engine of the 2010 Mercury Mountaineer, 23% of the 13 complaints for this model year. Where a mileage was given, the median is 55,000 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“While driving the Mountaineer I was slowing for a stoplight shortly after starting it up (had driven about 1/3 mile). The engine suddenly started to speed up and required significant extra braking force to come to a stop. I put the car in neutral and the engine ran at about 3,300 RPM for about 10 seconds. This is the third time this has happened. The first time the thermostat was replaced. The second time the throttle body was replaced. The third time the vehicle was checked but no defect could be found. …”
NHTSA complaint #10534451, filed 2013-08, 55,000 miles“Pulled into parking space, placed shifter in park, turned off ignition, released brake and vehicle rolled backwards as if not in park. Attempted to restart vehicle and no response. Set parking brake. Could not get vehicle to lock into park, shifter moved regardless of brake on or not and would not start. Moved shifter through entire range of gears and returned to park, vehicle still would not start and park would not hold. Called dealer and was told to have it towed in. Returned to vehicle and tried once more and it started and proceeded to respond normally. …”
NHTSA complaint #10460011, filed 2012-05, 6,125 milesRelated service bulletins
- 10143079Jun 1, 2018Various vehicles equipped with a 4.6L, 5.4L, 6.8L modular 3 valve engine built on or before 8-Jan-2016 may exhibit symptoms that may include upper end engine noise, rough…
- 10109070Sep 21, 2016The Powertrain Control/Emissions Diagnosis (PC/ED) manual has been revised for diagnosing electronic throttle bodies (ETBs). The ETC_ACT and ETC_DSD PIDs should not used to…
Engine: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2010 | 3 | 23% |
| 2008 | 6 | 6% |
| 2007 | 5 | 6% |
| 2006 | 14 | 12% |
| 2005 | 7 | 9% |
| 2004 | 8 | 4% |
| 2003 | 1 | 1% |
| 2002 | 2 | 1% |
| 2001 | 1 | 5% |
| 2000 | 4 | 3% |
| 1998 | 2 | 1% |
Other parts of the 2010 Mercury Mountaineer
5 complaintsVehicle speed control
4 complaintsFuel system
2 complaintsSteering
2 complaintsTransmission and drivetrain
2 complaintsElectrical system
1 complaintsInterior lighting
1 complaintsOther or unknown
1 complaintsSeat belts
1 complaintsSeats
1 complaintsBody and structure
1 complaints
← All problems reported for the 2010 Mercury Mountaineer
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 30, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology