i have no idea what this is, got my brakes checked its not them. it is as loud as it is at 30mph as it is at 5mph, it goes away when i hit about 2mph then starts up again when i start accelerating. engine revs have no affect and the brakes have no affect. it does it in every gear and is one constant pitch that doesnt vary with rpm's or speed except under 2mph. does anyone have this issue or have any idea what it could be?