I have a 2001 F-150 Supercrew with the 5.4L engine with about 98K. I am experiencing what feels like slipping when I'm at about 50 mph on level ground and not accelerating. Any idea what is causing this? I had the transmission flushed last year with BG. I called the dealer to set up for an appoint and they can't get me in until next week. Should I park it until I get it checked?

 

Took my F-150 into the shop and explained the symptoms and they had the transmission tech drive it and could not find the problem so they had their drivability tech (?) test it and he indicated the number 5 cylinder was missing and would need a new plug and coil pack. Don't know how that can possibly explain the problem I described but they said it happens again to bring it back in and they would dig deeper.....

 

Low grade misfire. This is common with COP ignition when a COP goes marginal.

At 98K have them change all the plugs, it's time.