Originally Posted by 06powerstroke06
Its nothing to worry about. just the boost that the turbo created that when you let off has no where to go but back out the way it came.
yea this isnt good.and i completely disagree about not worrying about it.anytime something that spins at 100,000+ rpms and then stops and spins the other way and back again is never good for the shaft or bearings of said object.and this is what is happening when this sound occurs.there are several ways to fix this problem.i wont start another back and forth arguement like what happened in the 7.3 section....so here are your options....upgrade your turbo(new wheels,housings, complete turbo) change what psi your boost bleeds out of your waste gate(egr on stock but yours is deleted) so buy a new waste gate, or buy a bov set up(if you dont like the sound and try really hard you might be able to find a recirculating one.).anyway all your decision.just know that once your turbo makes contact with the housing because it didnt seem important and pieces of the turbo then make it to your valves and pistons and destroy your eng,its no longer a turbo problem.i hope i have been the most informative about this as i can be.if you have any other questions please pm me and ill try to explain it better or more in depth.trust me that your turbo was only designed to spin one way.