hazard2k

iTrader: (10)

I got a RPM induced vibration that I am trying to figure out. Car details in my sig. It seems that when I get into the 5k-5.5k RPM range the shifter starts vibrating pretty bad. Its not bad in 1st – 3rd gears but in 4th and 5th it gets vibrating pretty badly. Its not a violent shake, but more of a very fast vibration. It feels exactly like those carnival “electrocution” games they try and make you hold onto that metal shaft that vibrates at 30,000 RPM for as long as possible.

I have stock motor mounts and a poly tranny mount. The tranny mount is a couple of years old, but is not VISUALLY broken at all. Could these just generally wear out and not shows signs of it?

Another thought I had was the engine causing the vibration. Could the underdrive pulley be causing it? Or how about a misfire? I did recently get a random misfire code, but assumed it was due to the cam.

Could my Fidanza flywheel be causing the vibration? I remember when I installed the clutch that it has 3 pins that line it up to the flywheel, but it could be clocked in any of the 3 positions. Could that be the culprit?

Its very annoying when I have to shut down the car around ~150 because it is vibrating so badly I cant hold onto the shifter any more…

Any help would be greatly appreciated!
-Jeff

P.S. sorry if this is in the wrong forum, I wasn't exactly where to throw it in.

iamnitrox

If youre misifring, I'd have to assume that could be it. Do you run 91 Octane? I dont think youre detonating or anything like that, but you ought to have some balancing checked I guess.