My transmission just started doing this. Yesterday, as I was pulling out into a rather busy road, the guy in front of my was moving very slow. I was moving slowly as well because of this. all of a sudden, my RPMs went up to 3k without gaining any speed!! I pulled into the nearest side road and stopped, then hit the gas again and it was back to normal. I will be checking my trans fluid today.. I'm freaked out now, and will probably have to pay for a trans rebuild... D: I only have 102k miles!!!