Yeah, i had one heck of a time with mine. I tried the DIY fix, but that didn't work. It finally got so bad that it would to it pretty much from 2000-2750 any time it was cold. Of course, I took my stang to the Dealer and they did it under warranty, but they cracked a couple of the bolt holes that the transmission mounts to and had to put in a new longblock. I was driving a Focus for like 2 and a half weeks, because they kept forgetting things like replacing the flywheel bolts.