There are 1 stored owner reports matching the fuel system leading-label group for the 2010 Mercury Mountaineer in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 1 of 1 matching reports.
Open the full vehicle complaint log (all categories)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. THE SECOND TIME I ALSO PUT IT IN NEUTRAL AND IT ALSO RAN AT ABOUT 3,300 RPM FOR ABOUT 10 SECONDS. *TR
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Apr 28, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.