i just purchased a ford bronco and now i notice a churping noise. it's gets louder at around 25-30 mph, but if you let off the gas it stops. it doesn't make the sound if you are just giving it gas in park (neutral). any ideas?!?!?!?

 

It sounds like the bearings in an idler tensioner pulley are going bad. My neighbors Chevy van always did this below 0 def. Farenheit.

 

My 300 does the same thing, but when it's wet or cold. I thought I pinpointed it to the PS pump pulley, but it might be the idler.