I cant believe nobody has figured this out...
ITS THE TIMING BELT!
im assuming you have a zetec(I4), because Ive never heard of a duratec(v6) pulling to dying timing belt symptons. Next chance you get, pop the hood of the car, go over to the passenger side, and remove the black pastic cover from the passenger side of the valve cover... This would be your timing belt cover... if your timing belt is BROKEN, or isnt tight then your timing belt is done for, and when a timing belt dies... its because a tensioner or two has gone bad.
WELCOME TO CEG!