i also have this type of noise but it seems that the car will do it when it pleaes cuz i can go days w/o it doing it. its also like a noice as if letting air out of a baloon. but mine will do it when it idles cuz i like if i rev it a tad it will go away but then as soon as i let off the gas and it goes into idle it may do it again. i also had someone turn it off and stuck my head under the hood and it came from around the same areas as mentioned earlier. i was going to change belts but since it didnt seem to work for AIRBOY. the car only has 34K miles hmmmmm im kinda stuck on this also