Whistling sound under dash
I have a whistling sound that sounds like it is coming from under my dash. My first thought was something with the turbo. Doesn't do it all the time, mainly when the truck shifts out you will hear it momentarily and sometimes when crusing at hiway speeds it does it on and off when you accelerate going up a hill or something. I searched the forums and found only a couple of threads related to this and the only thing mentioned was the waste gate. My turbo was replaced about two thousand miles ago. I did not start noticing this sound until after the turbo was replaced, but that was also about the time the temperatures started dropping here in the south, so I don't know it that has something to do with it or not. Anybody have any ideas what this might be?