We just took our F150 (ecoboost V-6) on vacation. On more than one occasion we were trying to accelerate to pass other vehicle's and we lost all power. We merged into the passing lane as we were accelerating and when I applied more throttle we lost speed and power. After this happened once we tried to duplicate it when we on the interstate and pretend we were going to pass other cars. The power loss happened about 50% of the time. Furthermore, this happened when we were just trying to get on the interstate via an on ramp and get up to speed. I did not "floor it" to get on the interstate, I did a more aggressive acceleration and the pickup shuttered and lost power. I asked Ford today (June 5th) if they had a recall on the vehicle and they said they might have an update, but nothing was certain. I consider this a serious safety hazard and we will not be driving the vehicle any more than we have to until this issue get resolved. I wasn't performing perfectly timed passes (we were on the interstate so there was no oncoming traffic) but this could be dangerous.

- Sandwich , IL, USA

I was driving at highway speed, and accelerated rapidly to get out of the way of a merging car. The truck shook violently and lost power. I pulled to the side of the road and restarted the vehicle. There was no "check engine light" or any other indicator of a problem during the incident, or after restarting the truck. When I took it to the dealer, they indicated that they found nothing wrong with it. I have driven the truck since then wondering if it would happen again. Now I see that others are experiencing the same issue. Kistler Ford in toledo, Ohio will have a record of this service appointment on 10-21-11, as I have a copy of the service document stating the above. Although I have no way to prove it, the truck has also seemed to have less power since this incident.

- Swanton, OH, USA

I would like to add to the complaints of the eco-boost. I was going about 75 mph on interstate in Alabama. Floored it to pass and engine went dead. Check engine light came on. Coasted to shoulder of highway and it started to sputter and was able to get to gas station on exit about 200 yds away. Turned off engine for about 10 min. Got back on highway(with engine light off ) and was able to make it back home in East Texas. Took to Ford dealership to get looked at. They put on some plate on the turbo cooling radiator. Last month, took it up to Iowa. Coming back, it did it again in tulsa ok. This time engine light on all the way home. Took to dealership, they said a 3 pronged cable, the prongs broke, going to one of the turbos.

- White Oak, TX, USA

Vehicle shifts hard when not under power. When under power vehicle backfires, mis fires, loses acceleration completely. Have brought vehicle to deal 4 times and have been told there is nothing they can do. There is black sut on the exhaust. I do not feel safe driving in the vehicle if it cannot accelerate or will just completely shut off.

- Cooper City, FL, USA

The contact owns a 2011 Ford F150. The contact stated that while driving 65 mph, the vehicle stalled with the illumination of the check engine warning light. The vehicle was taken to the dealer for diagnosis but they were unable to duplicate the problem. The vehicle was not repaired and the problem persisted. The VIN was not available. The approximate failure mileage was 20,000.

- Chagrin Falls, OH, USA

The truck has a hesitation at between 50 and 60 mph when going uphill in 6th gear. It feels as though the truck tries to shift but does not. Additionally at least two separate times the truck has lost power when attempting to pass another vehicle. Most recently on 5/29/2013 a vehicle pulled onto the road in front of me when I was driving approximately 55 mph, I pulled around the vehicle and accelerated to make it past the other car and avoid on coming traffic. The truck lost power and seemed to down shift. I let off the gas and tried to press it again with no response. At this point I was beyond the other vehicle and was able to get back into the lane and avoid oncoming traffic. The truck was still losing power so I attempted to press the gas again and the vehicle shuttered multiple times. I let off the gas again and waited a few seconds before accelerating and was able to resume normal driving. The weather was raining an humid at the time of the most recent problem. The truck has been brought to varney Ford in newport Maine at least twice for service of this problem. They have attempted multiple fixes but after the most recent attempt in September 2012 I was advised that the performance may just be "a characteristic of the vehicle" and that they could not do anything else to help. I have not contacted the dealer again because they appear to be unable to help.

- Dover Foxcroft, ME, USA

The contact owns a 2011 Ford F-150. The contact stated that while driving approximately 65 mph, the vehicle suddenly decelerated briefly. The vehicle was taken to the dealer for diagnosis. The technician was unable to diagnose the failure. The manufacturer was made aware of the failure. The vehicle was not repaired. The approximate failure mileage was 13.

- Florissant, MO, USA

Truck lost all fluid from transmission. Ford replace seal in transmission after sitting at dealer for nearly 3 weeks. Since that time, I have made multiple complaints to local dealer about engine stumble on hard acceleration. Dealer replaced air deflector per Ford service bulletin. Truck still stumbles on hard acceleration. (06/01/2013) current mileage 40,900.

- Ooltewah, TN, USA

Vehicle lost power while accelerating three times two times it was raining. Engine shook acted like it was running on 5 cyl instead of 6. engine is 3.5 ecobost. One time the check engine light came on two times it did not. I sent Ford an email on 12/15/11 and they had me go to my local dealer. The dealer was unable to duplicate the problem and there was no code in the computer. Ford was prompt in answering my email. I understand that NHTSA is looking at the problem and wanted you to have the information.

- Derby Line, VT, 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

While driving on the highway the vehicle seem to lose power I pull over to see if something major was wrong but nothing I can tell. I took it for service they told me the vehicle needed updates. A month later took another road trip the same thing happen, this is very dangerous. It happen on a major highway with vehicle driving at a high rate of speed and for my truck just loses power and speed on the highway.

- Columbia, SC, USA

Lack of acceleration - I had been driving on an interstate in heavy rain. I then stopped for gas. After stopping for gas I went through a toll booth and re-entered the interstate. The pickup would not accelerate at a normal rate. I could only go 30-40 mile per hour for the first mile or so then it returned to normal. The computer set a code. After returning home I took the truck in to the Ford dealer where I purchased the vehicle. They checked the code and replaced the converter asy.

- Austin, 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

The contact owns a 2011 Ford F150. The contact stated that while driving approximately 50 mph, the engine lost power for a few seconds and then resumed normally. The failure occurred whenever passing another vehicle at speeds of 55 mph or higher. The vehicle was taken to an authorized dealer numerous times and they were unable to remedy the defect. The manufacturer was not notified of the problem. The approximate failure mileage was 5,000. Updated 07/2/13

- Qunicy, MI, USA

I have had the stall and/or shudder problem several times. By far the worst is the date and items listed in the incident information. While attempting to pass another vehicle on a two lane highway, after driving in a steady downpour for at least an hour, my ecoboost F150 fell flat on its face. No acceleration at all. It just stalled and the check engine light came on. I let off the accelerator and tried again with no reaction from the motor. I then feathered the throttle and was able to get around the other vehicle. The truck would run as long as I didn't try to accelerate quickly. Luckily there were no oncoming vehicles in the other lane. With dryer weather the problem disappeared. Since that time I have had it shudder a few times when trying to accelerate. Mostly in damp or humid conditions.

- Kansas City, MO, USA

On two occasions on the same date I lost power under acceleration and on the second occasion I was presented a "check engine" light. The vehicle was delivered to billy howell Ford cumming, ga that same date and left with them while I was out of town for a couple of days. I had just had it in the same dealer on 8/30 complaining of missing and "backfiring", but they claimed nothing was wrong. The dealer claims to have replaced air deflector and problem has not presented itself to that extent again. However, I do experience fairly significant stalling or delay in accelerating from dead stop.

- Cumming, GA, USA

When accelerating my F150 cuts out and hesitates along with a rough idle. I have taken to local Ford dealer and it shows to be a misfiring issue in 4 of 6 cylinders. Ford recommended replacing a couple of parts, but it did not fix the issue. The printout given to me said it may or may not fix the issue and was under further investigation with Ford engineers. The truck has been maintained on time with scheduled oil changes, etc...the truck now has 75K miles and has an extended warranty up to 125K miles. Each time the truck has begun to misfire and stall out the engine light comes on and has heavy vibration until stopping and restarting the truck. The dealership replaced the spark plugs because they were all burned out which seemed to help, but continues to idle rough. It's just a matter of time before they burn out again. I spoke with someone from Ford and they offered me no help other than to stay in touch with my dealership which who knows when Ford will release a fix. I now pay for a truck that I bought an extended warranty for and does not run correctly. Everyone that rides with me has said, "man why does your truck idle like this?" my truck stickered for $41,460. This is unacceptable to have a nice looking truck that doesn't perform up to par.

- Conway, AR, USA

The first time I was accelerating in an on ramp to highway speeds when the engine started missing to the point I had to abort entering the highway and pull into the emergency lane to avoid the on coming traffic. I took it to the dealer and was told that nothing could be found wrong with the engine. This has happened numerous times and I keep getting told that there are no reports of this happening on other eco boost engines. My solution is to increase the distance to get up to speed with the approaching traffic which is not always a safe practice.

- Flower Mound, TX, 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

The vehicle lost acceleration in a major highway and started to smoke. My wife and I were almost killed when we tried to move off the road by a tractor trailer. There was no way of controlling the vehicle with no acceleration and major vibration of the truck. I notice that many others are having problems with the ecoboost F150 engines as well.

- Lumberton, NJ, USA