There are 1 stored owner reports matching the powertrain & transmission leading-label group for the 2009 Mercury Grand Marquis 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)MY WIFE WAS DRIVING AROUND 25 MPH AND LESS THAN ONE MILE FROM OUR HOUSE. WHEN SHE APPLIED THE BRAKES TO STOP AT A STOP SIGN THE ENGINE REVVED UP. I WAS RIDING WITH HER AND OBSERVED THE ENGINE REV TO AROUND 2,500 RPM BEFORE SLOWING DOWN. I ALSO OBSERVED THAT HER RIGHT FOOT WAS ON THE BRAKE AND THAT NOTHING WAS TOUCHING THE ACCELERATOR. THE CRUISE CONTROL HAD NOT BEEN TURNED ON. THIS WAS AT LEAST THE FOURTH TIME THIS YEAR THAT THE ENGINE REVVED UP WHEN THE BRAKES WERE APPLIED. THE DEALER COULD NOT FIND THE PROBLEM AND THE ENGINE DID NOT REV WHILE THE DEALER WAS TESTING THE CAR. *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.