There is a knocking feeling if I put my feet on the floor while I am in 4th gear and am accelerating moderately to heavily. One of my friends first noticed the problem (as the passenger always has their feet flat on the floor) and after I accelerated and put my foot on the floor I could feel it as well. This only happens in 4th gear and if I am pressing on the gas past maybe 1/4 of a way. Since I have owned the car (purchased at 22k miles) I have only put 90+ octane in it. There is no sound that I can hear when it does this. I looked at some other threads and couldn't find anything that seemed to talk about this specifically because it happens at any RPM within 4th gear. Any input is greatly appriciated, and if you know what is wrong and something needs to be replaced it would be greatly appriciated if you gave a good replacement part reference. Thanks!

 

Sounds like the throw out bearing. If you still have your warranty take it to the dealer and tell them your throw out bearing is bad. They'll check it out and either give you a BS excuse like they did for me, or replace it. The bad thing is they replace it with the same poorly designed bearing.

 

^^^ yes, throwout bearing rattle.