whistling noise 2000 5.4L
When I step on the gas peddle, at highway speed, I hear a whistling noise. The more throttle I give it, the louder the noise. When I back off the peddle, the whistle goes away. I'm a new owner, my other rig is an 85 F250, so I don't know if this is a normal sound, or if something's wrong. Any help is appreciated.