Brand-new car - 2 days old. Trying to merge into traffic on I-81 at night during light rain. Engine stalled during acceleration attempt while merging from the on-ramp onto right lane of interstate, forcing 18-wheeler to brake to void crushing me. Engine rumbled with very little power getting to the wheels, and recovered to normal driving mode within about one minute. Scariest driving event in my decades of driving. Internet research indicates that this seems to be a common problem with the 3.5L 6-cylinder ecoboost in humid weather, due to condensation in the intercooler being sucked into the engine, when accelerating sharply (such as merging into traffic, lane changes, etc., I.e., when full engine power is really needed). This will lead to fatalities eventually, if not fixed, but there seems to be no fix available from Ford.

- Hampstead, NH, USA

While driving my 2012 Ford F150 4X4 with the ecoboost motor to work on the garden state parkway I experienced the following issue: After cruising for about 20 miles at 65mpg I attempted a pass of slower moving traffic. The truck accelerated to about 80mph during the pass then suddenly the engine lost power and created an engine breaking situation. The trucks' speed dropped rapidly from 80 to 60mph and I had to abruptly move into the slow lane cutting off other cars to avoid being rear ended. As soon as the power/speed loss occurred the truck began to shake violently for about a minute or two until I eventually slowed to about 50mph. This has happened 2 times since owning the vehicle. The truck has 5000 miles presently and has been back to the Ford dealership 3 times for software updates, a catalytic converter replacement, to add an air deflector and it continues to throw codes and turn on the check engine light. I got it back yesterday and the check engine light went on again on my drive home. Also mileage seems to becoming progressively worse. I try to avoid passing situations as much as possible in fear the vehicle will create a dangerous situation for myself and other drivers on the garden state parkway.

- Toms River, NJ, USA

I was driving in a light rain when I gently pressed the accelerator and the engine started vibrating excessively making the whole truck vibrate like the wheels were falling off. The incident lasted about 10 seconds before it returned to acting normally.

- Missouri City, TX, USA