M998 6.2L engine popping/knocking

[timfi]

I was driving home in my M998 A1 being careful to not go over 55mph (just had my power steering unit and fan clutch replaced from a HMMWV outfitter), when suddenly a loud popping/knocking sound appeared (listen to video). I pulled over immediately and had it flat-towed back to the outfitter.

They have not been able to diagnose this (aside from put in new engine) and I'm hoping someone on this forum will recognize a familiar knocking problem?

Greatly appreciate any expertise on this one! I use my HMMWV to snowplow a long driveway ( and my neighbors) and need to get it operational before our snowfall starts.

Thanks!!!

 

[Mogman]

Just offhand it could be a bad injector

 

[gringeltaube]

.... (listen to video)

No link to it....?

 

[osteo16]

Well, I don't hear a dang thing..

 

[Mogman]

The reason I said injector is because it is one of the few things that can cause instant knocking that is not a fatal engine failure and it is so easy to troubleshoot.

 

[MrMikey4026]

Popping through intake?
Something failed in the valve train, usually an exhaust valve not opening.