I've been hearing some weird low volume mechanical noises that I've finally traced to the CD player in my truck. I don't hear it while it's playing, unless you turn to volume way down. It's sort of a clicking noise. It plays fine otherwise, just the noise. Can anyone tell me if they hear any sort of noise with a CD playing with the sound turned down?

EDIT: It turned out to be the actuator motor for the a/c unit and not the CD player. The old motor would hunt for an actuator door adjustment and was the noise I was hearing.