what could this be
 

when i lay into it it sounds like a machine gun and i loose power what could this be anyone

It is hard to say from the short description. But some thing that comes to mind would be an exhaust leak from the egr cooler plate on the back of the head.

turbo shaft slop?

But I am totally throwing darts blind folded LOL
Take a video if you can, Even audio may be helpfull.

Exhaust leaking from where....or if you hear casings hitting the ground someone maybe be firing a machine gun close by.