Engine Knock Need Help

[mprice1234]

Hopefully you find the cause and follow up with what it was as OP never did.

 

[bwep]

A buddy of mine made the exact sound. It's a broken plug. The noise is the arch snapping inside the porcelain. One of your 16 plugs is bad. Find it replace it and report back

 

[Canuck714]

Change your oil..
I Run 5-30 and if I've been running hard or getting close to a service mine will start making noise. Put fresh oil in it and boom quiet again for another 3500-4000 miles of abuse.
The oil starts to get a bit thin with age, so I assume some of the lifters dont get as "Pumped Up" as they should and have more slop in the valve-train...
Just my experience with the 6.2.. All 3 of mine have done the same thing.... Not as loud as this , but similar noise.