QUOTE(mxsteven @ May 26 2011, 04:03 PM)
hard to tell because there is too many factors that you havent test... is it exhaust? aircond compressor kick in only happen which the the expansion valve noise... engine firewall got hole where the air can leak into the car (u will notice when u follow the garbage truck or diesel vehicle... u can eventually smell everything lols... tyre? (not likely)Gearbox maybe? THe sound appear during throttle or not so long as the car is moving.
I saw a compressor being installed, the car owner said it is meant for saving fuel and let the car more powerful? Emr i doubt that.