Thanks so much! I'll ask my mechanic to do just that. It sounds like a prop plane going down the street! Since I'm always driving, I can't tell if it's coming from the center or not. Sounds to me like it's on the passenger side.

My 2006 V70 has 133,000+ miles. Something has started vibrating under the hood when shifting through gears and accelerating. No lights, codes, etc. but getting progressively louder. Noise subsides after reaching about 40 mph. Ideas?