Hey guys. I have a whistling around mid rpm's in each gear. Almost sounds like a turbo spooling. I listen to that all day long in my tractor trailer, don't feel much like hearing it in my gas pick up haha what could be making that noise?
Thanks

 

Vacuum leak would be one area to check. Do you have access to a smoke device? If so, disconnect the PCV tube from the drivers side that runs from the stock tube (air filter to throttle body), inject the smoke, and look for smoke escaping.

This is an easy way! Otherwise, you'll have to check for visual breaks in vacuum lines and connectors.