There are 4 stored owner reports matching the powertrain & transmission leading-label group for the 2006 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 4 of 4 matching reports.
Open the full vehicle complaint log (all categories)The contact owns a 2006 Mercury Grand Marquis. The contact stated that while stopped at a stop sign and attempting to accelerate, the vehicle failed to accelerate as intended. The contact stated that there was a loud clanking sound coming from the vehicle. The vehicle was towed to an independent mechanic where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 85,000.
I HAVE HAD 37 INSTANCES OF ENGINE ACCELERATION WHEN I BRAKE WITH MY 2006 MERCURY GRAND MARQUIS. THE FIRST INSTANCE WAS IN MAY, 2007. I DEPRESS THE BRAKE PEDAL, AND THE ENGINE FIRST SLOWS TO APPROX 850 - 900 RPM THEN BEGINS RUNNING UP TO OVER 2500 RPM. THE DEALER SAYS I'M HITTING THE BRAKE AND THE GAS AT THE SAME TIME. I'VE TRIED DOING THAT AND IT IS EXTREMELY DIFFICULT. I SUSPECT A COMPUTER MALFUNCTION WHERE THE BRAKING IS TRIGGERING A COMPUTER-INITIATED ENGINE ACCELERATION. *TR
SPORADICALLY AND WITHOUT WARNING, MY CRUISE CONTROL WILL ACTIVATE CAUSING THE VEHICLE TO IMMEDIATELY ACCELERATE. I HAD BEEN USING THE CONTROL BUT HAD DE-ACTIVATED IT BUT DEPRESSING THE BRAKE WHICH LEAVES THE UNIT "ON" BUT NOT ACTIVATED. *TR
TL* - THE CONTACT OWNS A 2006 MERCURY GRAND MARQUIS. WHEN THE ENGINE WAS STARTED IT WOULD REV VERY HIGH. WHEN THE BRAKES WERE APPLIED THE VEHICLE WOULD ABRUPTLY GO INTO DRIVE. THE FAILURE OCCURRED INTERMITTENTLY. THERE WERE NO WARNING INDICATORS. THE FORD DEALER WAS UNABLE TO DIAGNOSE OR DUPLICATE THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 200 MILES, AND THE CURRENT MILEAGE WAS 11,000 MILES. *AK
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.