I am getting the exact same noise on my 2002 WRX, only it is starting much sooner, pretty much anytime during acceleration. I started hearing it after my car had been repaired from hitting a deer. When I took the car back to the dealer, I was told that the noise was the turbo going bad. SO, I replaced the TD04L with a brand new one, and guess what.. Still getting the exact same noise. I have GOT to get this noise fixed, as it is very annoying and very audible from outside the cab. Was the mentoined repair difficult to do yourself, or did you have the dealer do it? Any help/advice is appreciated.