My Tahoe started making this sound out of nowhere last week. While at idle, there is no noise, but as soon as I start moving, you can hear sort of a winding up sound. To me, it sounds like the noise is coming from the front end of the truck, but I'm not 100% sure. As far as how it drives, it seems normal. 2005 4.8 2WD. Can someone help me identify what it could possibly be.