I recently purchased a 2006 Saab 93 Aero 6 Speed manual, 130k on the clock, I've put about 5k on it. I bought it stock and was quick to get a downpipe installed and vtuned. It runs great, but I have noticed a loud hum/vibration when decelerating while in 3rd and 4th gear after some hard acceleration. The sound and vibration stops when I press in the clutch, but I can also feel it between shifts during spirited acceleration. If I don't press in the clutch, it will last for about ~1500rpm or so while decelerating, then goes away. It almost sounds like wheel rub or when driving on rumble strips (not quite that bad but it's hard to not notice). I doubt it is wheel rub, I run the stock 17's with Koni yellows and Eibach springs. I'm starting to worry it is the transmission. Does anyone have an idea what the problem could be?
edit: Forgot to mention I also have a GS torque mount installed
edit: Forgot to mention I also have a GS torque mount installed