I need you to check two things. First, wheel bearings. A wheel bearing can make a sound as you described. However, usually the sound will change when you make turns. Picture a left side wheel bearing being bad. If you make a left turn, the vehicle's weight shifts from the left to the right side of the vehicle. At that point, the sound usually gets quietier. The opposite will happen on a right turn.
I also want you to check the backing plates behind the front rotors. I have seen many times that either the result of rust or being bent, the backing plate will actually rub the brake rotor and make a similar sound.
Also, can you tell aprox. Where the sound is coming from?
Let me know what you find.
Joe
Wednesday, November 18th, 2009 AT 6:37 AM