not sure if this is the correct place to post this bt i have a 2012 ford f350 88k miles when I oush the gas pedal to the floor it will take off for a second then start bogging down and all the valves start clattering sounds awfull. check engine light came on and flashes when its bogging code reads cyl 8 mis fire, I have put a coil pack and injector on # 8 didnt help any suggestions ?

 

I hope you got your truck fixed by the time you read this. I just joined the forum. Had the same problem and it was hydraulic lifters floating when the engine was revving. Sounded like the pistons were swapping holes.