I have a civic 2002, it runs fine but when I put the 3 gear and accelerate after 3000RPMs the engine rev ahead just like when you have a clutch slipping. It goes up to 4000RPM then goes back and catches up with the regular RPMs (going back around 3500); after you shift and the issue happens you can accelerate the car to the metal that it runs fine. This is happening with gear 3 4 and 5, in the gear 5, If I accelerate slowly it kind of does not do that. I was thinking that could be the clutch but it will be slipping all the time, I’m afraid that the transmission has something to do with this.