Well the banging I heard I think was coming from the starter after finding a couple of the starter bolts missing. As far as running it I have tried to get it to run so I could try to get a code to pop if some kind and so far nothing, only thing the truck has had change is the battery light coming on when it first died and saying to check charge system. I have a couple warm days coming up this week I’m gonna try to figure a way to get it moved ti where I can work on it and start at the turbos and work my way down. Might be a hassle with the cab on but I have no way at all to remove the cab I could jack it up with jacks and wood but would rather to just take the core support out and try to just take my time with the cab onDon’t try to run the engine until you figure out the issues. You’ll probably just cause more damage to it.
Take the valve covers off and check the rocker arms for failure.
If those are OK, run a bore scope down the glow plug holes and check for piston damage.
215K is a lot of miles on a 6.4L
Oil leaks are pretty common.