Looking for any guesses on what this could be. When the truck is cold, I get a high pitch whine for the first 10-15 minutes of drivining. After that, it goes away. It sounds similar to a sewing machine going full bore. It does it predominatley when I am accelerating, but not when stopped.

Thanks,
John

Also have the same noise. From what I remember, it shouldn't cause any harm.

its normal.. its the variable veins/vaines on the turbo. when its cold they close and limit boost..as the engine warms up they open up as well and the sound goes away.

very normal and is for engine/turbo protection. Its made so you don't start up a cold diesel and then floor it and break something.

Thanks for the info.

John