2018 Lincoln Navigator POWER TRAIN,ENGINE

The contact owns a 2018 Lincoln Navigator. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power. The vehicle lunged forward. Additionally, the contact stated that the vehicle was shifting roughly. The contact stated that the vehicle would redline. There were no warning lights illuminated. The vehicle was taken to the local dealer, where it was determined that a transmission flush was needed. The vehicle was repaired, but the failure recurred. The vehicle was taken back to the same local dealer, who was unable to determine the cause of the failure. The manufacturer was contacted, but no additional assistance was provided. The failure mileage was approximately 86,000.

While driving at a speed of 55-60mph, I tried to pass slower vehicles on three different occasions during the same trip on a two lane road. I pushed the accelerator to the floor and pulled the car into the lane to my left. I felt and heard a very loud clunk, revving up of the engine, and total loss of power at the wheels. I quickly moved backinto my original lane and let up on the accelerator. After a 5-10 seconds, power returned to the wheels and I was able to reaccelerate. I was able to pass the aforementioned vehicles, albeit using a more gradual acceleration. I have previously had the vehicle inspected for two identical episodes at a Lincoln dealer. Unfortunately, they reported that the service techs were unable to duplicate the problem. If this were a standard transmission vehicle, I would say the clutch was slipping. In a vehicle with four wheel drive and automatic transmission, however, I am not well enough informed to make a diagnosis. There can be no doubt, however, that the action is potentially dangerous and could result in head on collision. I would also suspect that the engine transmission train is likely to have shortened lifespan if the problem continues. It is possible that there is already damage.