There are 8 stored owner reports matching the powertrain & transmission leading-label group for the 2021 Ford Mustang 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 8 of 8 matching reports.
Open the full vehicle complaint log (all categories)A steady Check Engine Light came on after starting the car; brought it to Ford Dealer of Montebello and they stated coolant leak and got into one of the cylinders that caused misfires.
Vehicle stalled while pulling into traffic from apartment driveway.
Vehicle has serious transmission problem, jerking on upshifting, downshifting, banging when changing gears - any speed, skipping gears, slipping while shifting, making grinding sounds, whining sounds when shifting gears, clunking sounds while shifting from park to drive, reverse, neutral. Vehicle have no power, hardly moves.
At idle the engine idles roughly and rotates randomly at speeds from 300 to 900 RPM. When starting from a stop such as a traffic light or when pulling onto a roadway hesitation is often noted and on several occasions this has resulted in near accidents as the vehicle won't proceed as required to move through an intersection.
While driving my 10R80 automatic transmission shifted into neutral even though the shifter was positioned in drive. I was unable to accelerate and was forced to pull over on the side of the road to prevent an accident from occurring. I placed the shifter into park and turned the car off. I then started the vehicle back up and began driving. The transmission continuously shifted rough while driving my destination.
1st dealer visit: at low speeds car acted like it was in neutral and then surged when trying to accelerate. Dealer said they corrected the issue. they did not. 2nd dealer visit: car was still doing the same as number 1. While on the highway with cruise control set at 75 mph, I lost power and smoke started billowing from under the car. transmission was shifting erratically, went into limp mode and i made it off the highway to call a tow truck. Dealer said they repaired the issue. 3rd dealer visit: car is still doing the same as number 1. now the car is also very jerky in 3, 5, 8 gears. I almost ran into my own car while parking due to the random lunging. It hesitates and stumbles in most gears and I have no confidence when pulling out onto a street or trying to pass on the highway. It shifts extremely hard from 4th to 5th gear; feels like I ran over something or got rear ended. The dealer wants to repeat the same repair they tried in visit #2, new valve body. -Transmission failed. dealership says valve body but the new one is broken also. waiting on the 3rd one for this car. Possibly available for inspection; it is at dealership. -Random lurching at low speeds and power loss on the highway are my safety concerns. -Dealer found the issue and attempted repair. -Manufacturer, police or insurance have not inspected. I have a ticket open with Ford currently. -Warning lamps? not on the 1st visit. yes, when I lost power on the highway but the light came on well after the issue was apparent with smoke behind me. 3rd visit, no warning lamps.
Vehicle bucks at low speed after putting in drive and when driving during downshift, on 4 occasions I almost hit my wife's vehicle during low speed bucking with the trans
After slight acceleration and then light braking vehicle wants to lunge forward and is a outright safety hazard in 3 separate incidents it almost caused an accident and one was a pedestrian, fors is well aware of this vehicles incidents and well documented by text from dealer acknowledging such incidents
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 29, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.