Any ideas of what this noise could be, i attatched a youtube video of what it was doing? Blown rod, bearing or valve bad? Everything runs normal just that noise. 1999 ford f150 super cab xlt, 4.6 liter v8 triton, 412,000 miles on it. https://youtu.be/ChN_wPSA39k

 

No video for me.

 

 

Sounds like a god awful exhaust leak... notice rusted off exhaust manifold bolts? Are you missing an exhaust manifold? LOL

 

AHAHHA I hope not buddy! lololol will check tomorrow, need to go to bed soon to get back to work. Thank you for your answer.

 

Take the belt off and see if it disappears. Sounds to me like it might something on the FEAD doing it (water pump, compressor, idler pulley).

 

My WAG, rod or possibly wrist pin, i'm leaning rod, rev it up a few more times and we'll know for sure. Hopefully i'm wrong, but with over 400,000 on it you can't complain.

 

I'm torn between it just sounding like an echo (so more exhaust leak) or metal slapping (something on the feed side like you mention)
I think a video of the engine bay with the hood open would help us. Had to watch it a second time but I can see where you're coming from.

 

The EGR tube broke...my guess.

 

Ain't that the truth!