I have a 96 ford contour and it is giving me some trouble. when i am driving the car out of no were it will rev or when i put the ac or defrosters on the engine revs up. now tonight on my way home i couldn't get the car to go over 60? whats the deal? my mechanic said it would be something with the transmission like something sticking becuase of the hot weather but it is getting cooler now and stoped and just started again. any ideas?