I thought it was my turbo but I just put in a brand new one and still have the problem.

When I just start my car and its cold I get a vibration when I hit my throttle and let off as the rpms come back down. I feel it most if I put my hand on my turbo's compressor housing or that general area. It pretty much goes away once the car is warmed up. Car still runs fine though. Any ideas?

thanks