I was driving down the road and I heard a loud pop. The engine had a very abrupt loss in power and began shaking as I tried to accelerate. I was on a 2 lane road and had no choice but to try and maintain my speed to prevent causing an accident from being rear ended. After driving several miles to a place I could safely stop, I checked under the hood an a spark plug had been shot from the engine. After reviewing this on the web, there are many complaints like mine where spark plugs were shot out of engines. NHTSA needs to evaluate this as review. Had the engine caught fire I would not have known and I had no where to pull off the road. This is a result of an cylinder head with inadequate threads for spark plugs to thread into and take hold over time the aluminum weakens and this happens. If this wasn't a problem why did Ford redesign cylinder heads after these model engines to accommodate more threading to hold the spark plugs in the engine?

- Frankfort, KY, USA

The contact owns a 2003 Ford F350. The contact stated that while driving 45 mph the transmission started slipping and the vehicle stalled without warning. The contact was able to restart vehicle. The vehicle was neither repaired nor taken for diagnosis. The manufacturer was notified of incident. The failure mileage was 47,000.

- Owego, IL, USA