I am getting a whistle noise when I push down the gas pedal a certain amount. Once I hear the noise if I leave the gas pedal where it is the whistle noise does not go away, but if I let up on the gas or press it down further it goes away immediately. It is just making the noise when the gas pedal hits that one spot. It also only makes the noise when im going over 35-40 mph and up. Any help would be greatly appreciated.