While attempting to accelerate back to highway speeds after slowing down for a car leaving the highway, my truck lost power and started to shutter. The engine light was flashing and I was unable to maintain highway speeds. I exited the highway and after about 2-3 minutes I was able to accelerate normally. Conditions were wet and the temperature was around 70F.

- Smithfield , NC, USA

Vehicle began shuddering heavy between 40mph and 50mph. Requiring me to depress the gas pedal heavy to avoid the shuddering, its almost impossible to drive my vehicle at 45 mph (which is the speed limit in most of the area I drive in). This occurrence is when 5th gear changing to 6th gear, which is typical between 45 mph. Not sure what damage this is doing to my vehicle, let alone the safety risk this may be causing. I have had the vehicle in the dealership at lease 6 times for this issue and with no results of the issue being resolved. Just the run around and false promises. 2011 F150 5.0 motor and 3.55 gear ratio.

- Miami, FL, USA

2011 Ford F 150 with eco boost. When I accelerate the vehicle stalls out, bogs down, looses power and shutters. I have taken in the shop several times and they could not fix it. I recently took it back in and hey changed the spark plugs which helped a little however still really rough. I am thinking of filing. Lawsuit against Ford. I have tied to trade out of the vehicle and I'm upside down because of bad publicity I'm being told. I thought I had. Lemon but I guess it's all the engines.

- Southlake, TX, USA

Vehicle shut off going up hill weather cold and damp took truck to dealer on 5/20/13 found nothing wrong. On 5/25/13 vehicle shut off 11 times while accelerating. Drove vehicle on mon May 27 shut off 9 times and we were nearly run over by semi on interstate. Engine light came on on Tuesday May 28 drove to dealer with vehicle shutting off over 10 times. Vehicle is a liability as well as a safety hazard for driver as well as other drivers.

- Watsontown, PA, USA

Accelerating onto interstate from on ramp, sudden loss of power, vehicle shuddered, lost power and speed. Vehicles around me on interstate had to swerve to avoid hitting truck. Truck gradually regained speed over next 1/4 to 1/2 mile. Approximately 24 hours and 400 miles later the check engine light came on.

- Charleston, SC, USA

Driving on new years day, I was traveling and needed to accelerate onto an expressway. As I pressed on the throttle pedal my Ford F150 2011 seemed to lose power for a second or two before regaining power again. This was the first time I can recall, but it happens each time I press the throttle all the way down for acceleration. I have learned that my F150 is not reliable enough to attempt to pull out unless traffic is completely cleared, or I have several car lengths of distance.

- Commerce Twp, MI, USA

Loss of power during acceleration with ecoboost engine. I have been complaining to the Ford dealerships about this since right after I bought the truck. Thank you for putting this problem in the media as I am now hopeful for a resolution. I called the Ford dealership this morning and they said they knew nothing about it and to contact Ford. Here we go again with no one in Ford service departments wanting to acknowledge and resolve the problem.......

- Angleton, TX, USA

Traveling on I 20 during heavy rain, got off interstate to refuel and after reentering interstate accelerated to get back to highway speed and truck stalled went to shaking real bad and engine light came on. Would not accelerate just shook real bad and I pulled over turned it off for a few minutes and restarted and continued on. No more issues once the rain stopped.

- Vicksburg, MS, USA

After 4 hours of steady highway driving upon attempting to pass a vehicle the truck failed to downshift, lost power ( requiring me to abort maneuver) and began bucking... there was no cel. Took the car to the dealer and they inspected the truck found no codes and said no problem found. They said they reloaded the programming for the transmission. This vehicle has experienced this problem numerous times since the first occurrence. Always happens when accelerating and creates dangerous loss of power at critical driving periods.

- Columbia, MD, USA

The contact owns a 2011 Ford F-150. The contact stated that while descending a steep grade, the rpms greatly increased and the vehicle erroneously accelerated. The contact also stated that the engine hold back disengaged. Once the rpms decreased, the engine hold back engaged and the vehicle decelerated. The vehicle was taken to the dealer and the contact was informed that the transmission fluid was low but the vehicle was operating as designed. The failure recurred again and was taken to the dealer, who referred the contact to the manufacturer. The vehicle was not repaired. The failure mileage was 15,500 and the current mileage was 18,000....updated 02-07-13 updated 02/13/2013

- Simla, CO, USA

Yesterday I went to pass a truck that made an illegal turn, and had to hit the gas hard to get out of the way, only did it for about 2 seconds, than when I let off the gas, the engine kept running at high speed for about another 3 seconds? and my foot was not on the pedal at that time.

- Leesburg, GA, USA

The contact owns a 2011 Ford F-150. The contact stated that while driving 65 mph, he attempted to accelerate and the vehicle decelerated to 10-15 mph. The contact stated that the vehicle performed as if the engine was not receiving enough fuel. The vehicle slowly began to accelerate up to speed. The vehicle was taken to the dealer, however no failure codes were found. The manufacturer was notified and they offered no assistance. The vehicle had not been repaired. The failure mileage was 3,000 and the current mileage was 41,000.

- North Lauderdale, FL, USA

While entering a highway via an on-ramp doing about approximately 45 miles per hour I attempted hard acceleration to pick up speed and merge in to traffic that was doing approximately 65-70 miles per hour. When I depressed the throttle the vehicle did not accelerate, but it started to hesitate and shake. The check engine light came on and the vehicle would not go over 40 miles per hour. This almost caused an accident situation as I expected the vehicle to accelerate when it did not. I was then forced to pull over to the shoulder and shut the vehicle off. After restarting the vehicle the cel had cleared and the vehicle was operating normally. No code was stored in the PCM to indicate what the issue was. This happened several more times since the first incident. Once while towing a 4000lb boat/trailer which also almost caused a severe accident. Ford has found nothing wrong with the vehicle and concludes there is nothing they can do since no codes were stored. I will note that after receiving tsb 12-2-10 the vehicle will still exhibit the same symptoms described above, but now the check engine light does not come on. Vehicle will stall, go in to "limp mode" with no indication that anything is wrong. Only resolution is to turn the vehicle off and back on to clear the status. This creates dangerous situations when on a highway. Completely unacceptable.

- Concord, NC, USA

F150 ecoboost while going down a slight grade at about 50 mph in drive the transmission suddenly shifted down a couple of gears thereby causing the engine to rev up to over 3,500 RPM. After several seconds the transmission shifted back up one step at a time to the 6th gear. This has happened at least twice on different occasions. Another anomaly has occurred several times. While slowing down slightly the transmission suddenly 'clunks' and it feels like something has run into the back of the truck. It's like a hard shift into a higher gear, however the transmission appears to be 6th and the speed is around 60 mph..

- Princeton, MO, USA

The contact owns a 2011 Ford F-150. The contact stated that while driving 70 mph, he depressed the accelerator pedal and the vehicle stalled without warning. The vehicle was taken to an authorized dealer, who was unable to duplicate the failure. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure mileage was 5,536 and the current mileage was 11,800.

- Santee, SC, USA