Attempting to accelerate to pass a slower vehicle on the highway. Truck began shuddering and immediately decelerated to 50mph. Would not respond for approximately 75 yards, then would not accelerate over 60mph. Two vehicles (one of those vehicles was a tractor-trailer) following had to take evasive action to avoid rear-end collision. Exited the highway, put the vehicle in park. No warning lights were engaged. Weather was sunny and warm. Now vehicle is shifting very hard with a delayed engagement between 55-60mph.

- Newcastle, OK, USA

Same as previously reported by many others: Misfire upon acceleration up a hill; reported to dealer who found no error codes. Happened again soon after, this time activating engine warning light. Dealer replaced cylinder coil; next day, same type of misfire occurrence. Very unsafe situation, costing me lots of time and money. In addition, this eccoboost, as I have reported to Ford since it was new, has never achieved even close to rated mpg, only averaging 14 mpg or 40% less than advertised. Vehicle now back at livermore Ford, where technician was asked by service dept to drive unit home hooked into computer to see if problem can be diagnosed. This is an unacceptable and unsafe situation. Not happy.

- Pleasanton, CA, USA

While towing my camper at 60 mph up an incline my 5.0L F150 began to lose power, as I increased pressure on the accelerator the power to the vehicle decreased even more. The service engine light came on and I limped up the hill at a whopping 20mph on the interstate. Once on the downgrade the vehicle came back up to speed and the service engine light went off. The truck continued to have power issues and a knocking from the motor when I was climbing hills. I took the vehicle to the Ford garage and they told me there were no codes to tell them what was wrong. The vehicle still has the apparent miss and knocking sound at certain RPM's and now has an issue starting for the first time of the day. I again took it to the Ford garage when the starting issue was happening and they told me again that the vehicle still had no codes to explain this problem. I tried all of the easy fixes but the vehicle still has the same starting and power loss issues and Ford can not tell me what is going on with my vehicle. My best guess is a catalytic converter issue, but I can do nothing about it until I know for sure.

- Shawnee, OK, USA

The ecoboost engine Ford introduced into the F150 (and other vehicles) in 2011 seems to be having common and widespread problems, including my vehicle. I first reported this issue to the dealer with about 30,000 miles and now again at 63,000 miles. The safety issue is revealed under any acceleration "event" such as highway merging, passing, towing etc. Under acceleration the vehicle "chokes" and will not accelerate as the driver & passengers experience the vehicle stalling, shuddering or bucking. This is often described as the vehicle going into "limp mode" operating on fewer than all cylinders. The problems appear to stem from dysfunctional intercooler operation on this twin turbo engine. There are two different scenarios described in F150 blogs. One, most common, is that the cooling of the air via the intercooler causes condensation to accumulate inside the air intake. When the driver accelerates, the increase in air volume draws the moisture into the fuel delivery system and causes the engine to misfire, which the driver experiences as an engine stall, bucking or shuddering. The second scenario reported is that there is an overheating of air into the fuel deliver system which causes early detonation of the fuel mixture in the cylinders causing roughly the same symptoms. My vehicle repairs are costing me almost $700 - which would be more if I did not have an extended warranty. The dealer is replacing 6 spark plugs, 4 coil boots that have overheated and cracked, installing a new intercooler shield - none of which they are standing by as a dealer covered expense. Ford needs to be held accountable for this defective design for both consumer safety and financial reasons. Someone may be killed trying to pass or enter a highway as their vehicle suddenly looses power.

- Knoxville, TN, USA

There is a problem with the engine misfiring at moderate to hard acceleration. This really bothers me. As I have talked with Ford mechanics I have been told that Ford has no fix for this problem. From what I have read and studied, this is a problem with condensation in the intercooler making its way to he injectors. Once you put your foot on the gas pedal to accelerate you experience a sometimes violent stutter and the vehicle not accelerating but instead sounding like it's going to explode. I have also heard this happens when its humid outside. Regardless, one day I'm going to need to accelerate away or from something and the truck is going to fail, causing me to get hit or killed. I have found fixes to the problems including a full race intercooler, plugs and wires, however I don't think I should have to spend over $1000 for something Ford released knowing it wasn't ready, or up to par. I've owned my vehicle for over a year now and its 0% better even using top octane fuel. Please help...

- Palmetto, GA, USA

Water from the cac was ingested into the engine causing a misfire. This is the 8th time it has happened to me. I have had all tsb's completed by Ford and the issue still persists. The ecoboost engines are unsafe. This loss of power while merging has causes me to narrowly escape accidents 2 out of the 8 incidents. I noticed that the NHTSA closed an investigation into the ecoboost issues earlier this year. I'm suggesting that the NHTSA re-open that investigation. The tsb's are not fixing these issues and it is only a matter if time before someone is seriously injured. Please contact me with any questions.

- Collierville, TN, USA

As I was merging onto the highway, I had to accelerate to avoid a semi who was approaching in the right lane. I hard accelerated, but the truck started shaking and the check engine light began flashing. I had lost all acceleration and was forced to put my flashers on and merge to the break-down lane to avoid being run completely off the highway. The truck shook violently while in 6th gear and I had to manually shift to 5th gear to stop the truck from vibrating apart. Less than 10 minutes later (while driving down the highway in 5th gear) the check engine light turned off and the truck was able to be shifted back into 6th without any vibration. This lack of acceleration is extremely dangerous and has happened more times than I can count. Above was only an explanation of the last occurrence. The truck has been serviced (under warranty) where issue was discussed with Ford, but they were unable to "reproduce" the problem...

- Houston, TX, USA

Coasting at low speed around 7mph I attempted to accelerate, instantly as I put my foot on the gas pedal, now not even making it to 10mph, the 3.5L ecoboost engine made an incredibly loud and hard bang and continued to grow louder and shake more violently. I came to a stop on the side of the road I shut down the truck to find oil spilling from the passenger side of the block. I had the truck towed to my local dealership and they found that two connecting rods had broke and destroyed the block. They is no concern from anyone at Ford about how this could have happened.

- Berwick, ME, USA

Truck has a 36 gallon gas tank. Fuel gauge does not go to full when filled. While driving fuel gauge goes to empty and message center comes on low fuel 10 miles to empty. Tank still has 20 gallons or more in tank. When filling with gas after this happens there is a high pressure release of gas fumes from the filler neck when pump nozzle is placed in the neck. An audible whoosh sound is made and the build up of gas fumes is consistent with every time the gauge and message center think the tank is empty. When starting the truck after this occurrence it takes 2-3 tries before the engine will start. The engine malfunction indicator lamp will come on for 3-20 minutes before going off. The Ford vehicle health report reads "engine, transmission, amp; emissions. The truck has been serviced 8 times with no corrective results. My major concern is the build up of fumes and the possibility of fire. It appears that Ford has known of this problem with trucks having 36 gallon tanks since 2008 based on comments from other owners when I googled my problem. To this date Ford does not appear to have a solution to the problem.

- Palm Coast, FL, USA

Under hard acceleration on the highway, the engine began to cut out and misfire, then the check engine light began to flash. I took the vehicle to the dealership and they said the innercooler had failed and needed to be replaced. Now, at roughly 55,000 miles it has begun to do it again, I had noticed it some before, but now it is worse. I took my 2011 F150 with the ecoboost to the dealership again and they said a tsb had been written and they changed the replaced the lower air deflector. This actually made the problem worse. At wide open throttle from a stop to about 80 mph, every gear will cut out and sometimes put the engine into a protection mode beginning around 4,000 RPM. If it shakes and shudders made enough the check engine light will flash, and now it has come on and stayed on. It has been very dangerous if I pull out to make a pass and then the engine shuts down and I can no longer accelerate. This has happened dozens of times, and has been addressed twice now by the dealership without any fix.

- Goshen , KY, USA

We were merging onto the highway outside of St. Louis mo and when the accelerator was fully depressed the engine started to misfire and power was reduced. A blinking cel was displaying on the dashboard. It seemed as though the turbo system was not adding any extra charge to the ambient air. There was a pronounced vibration to the vehicle that seemed to originate from the engine/drive train. Luckily there as not a lot of traffic at the time and our poor acceleration did not result in an accident. My solution was to manually select the gears and drive at much higher RPM. This smoothed the misfire and we had an adequate amount of power to keep up with traffic. After about 10 minutes everything smoothed out and the misfire was gone. Truck behavior returned to normal. The weather that day was a pleasant 60 degrees and sunny. The previous day we drove from central Ohio to St. Louis through much rain and fog. Since we were on vacation and away from home we did not take the truck to a dealer to be serviced. The problem has not occurred since then. There was one previous occurrence at a previous date. I don't know exactly when it was. We were traveling home to vt from Ohio. We had been driving for many hours, mostly on highway/cruise control driving. We had just gotten off the interstate highway and were on state highway. I went to pass a slower vehicle in my lane and upon depressing the accelerator the engine seemed to misfire (RPM went up but power delivery fell flat). I stepped off the gas pedal and slowly pressed a second time and this time the truck responded as expected. There was no cel this time. Each of these incidents occurred with my entire family in the vehicle. We were not very happy about it and did not feel safe at the time.

- Essex Junction, VT, USA

Engine misses at times of hard acceleration. Engine ecoboost.

- Gravette, AR, USA

Had a car pull into my lane, tried to accelerate to move over with out causing a dangerousness situation of a car coming up in the lane I needed to be in to avoid the idiot moving into my lane but car lost power. Thankfully the car in the next lane over saw the issues with the car moving over into me and gave me room, I'm sure they didn't expect my car to slowdown due to the loss of power. This car has the ecoboost engine 3.7 liter

- Palm Beach Gardens, FL, USA

This is on the ecoboost F150. I was driving during a rain and had been around 70 miles. The weather was rainy. I went to pass a farm tractor on a 2 lane road and the vehicle stuttered and had no power to pass. I had to take evasive action and get back into my lane where there vehicle continued to sputter for approximately another 2 minutes. I took truck to Ford and they replaced a converter and cooler. Last Wednesday under similar conditions, the same thing happened again on a vacation trip. Oncoming traffic had to evade me as I tried to get back into my lane. It has been less than 10, 000 miles since last attempted repair was performed by dealer. Obviously the repair did not work and now I am left with a vehicle with an obvious design defect that Ford doesn't know how to correct. Under different circumstances, this could be a serious safety issue.

- Alabaster, AL, USA

Traveling on 4 lane highway during period of train, accelerated to pass vehicles, my truck eco-boost motor acceleration stagnated and vehicle began to shutter, was unable to pass, decelerated and stagnation stopped. Incident occurred when ever I tried to accelerated during active rain during a 9 hour interstate trip.

- Spring Lake, ND, USA

While merging into traffic on the expressway today in miami, at about 35 mph, I had to accelerate to get out of the merging lane, at which time (for the third time since I bought the truck in 2011) the truck lost all power to the engine (a 3.5L ecoboost) and began to sputter, shake, and decelerate. Luckily for myself and the other drivers on the road I did leave a sufficient gap between myself and the car to my rear to give that vehicle time to react to what equates to a vehicle pulling out in front of him/her and gently pressing the brakes without the brake lights engaging. My truck hovered between 25 and 30 mph for about 30 seconds with it doing the sputtering and slowing thing each time I attempted to accelerate during that time period. After pretty much coasting for 30 or so seconds, the truck sprang back to life and drove as advertised. From what I've read, this is not an isolated incident and I (as well as others) believe Ford should be held accountable for this defect. I'm not looking for a new truck, I'd just like the problem fixed. Even though no deaths or injuries have been reported due to this "yet", you can see the danger of having your engine loose power when you need it the most. Unfortunately for their customers, all Ford seems to be concerned with is the loss of a buck......not the loss of a life!!! [xxx] information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Sunrise, FL, USA

Poor gas mileage. Window sticker says 23 mpg highway, best I ever got is 16 mpg, with cruise set at 65 mph on flat level highway. Had at dealer, 4 times, they updated computer, changed turbo intercooler and they still cant improve my fuel economy. Around town I get 12 mpg. Bad turbo lag when pulling out low power, dealer said its how turbos work. Doors rattle, speakers crackle, rear end springs make a creaking sound. 4 wheel drive makes a loud growling, sounds like gears are not meshed right. I would not recommend a new F-150 to any one. Nothing but trips to the dealer and let downs.

- Windber, PA, USA

My Ford F150 eco boost lost power suddenly while trying to enter a rural route at a stop sign.while trying to accelerate it just died for several seconds and then took off since I was pushing on the accelerator wondering what had just happened.the vehicle has been shuddering a lot on acceleration now with a substantial loss of fuel economy. I have personally had it at two Ford dealership which say they can find no problem with it, but shop foreman told me and my wife we where stuck with it and to fix it by pulling the battery cable off every once in awhile.

- Rhoadesville, VA, 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

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