2005 Cummins, no start, turned to rough idle and runaway
 

2005 Cummins, Automatic, CAI, 237,000 miles. No Mods, No Codes
My buddy had his truck towed to my place with a story of "it driving down the highway just fine, then it started shaking like it had a flat tire, pulled over and it was running rough and then died. Cranked over like it had no compression and wouldn't start."
My first thought was a fuel issue, so I took the supply line loose from the injection pump and bumped the key, all kinds of fuel flowing, so not the lift pump. Unplugged FCA, since previous test covered it in fuel, cleaned connector with brake clean and blew out with air, plugged it back in. Just for giggles tried starting again and it acted like it wanted to fire on a couple cylinders and was belching white smoke from exhaust. So thinking FCA is the only thing I've messed with I replaced with known good one with no change in symptoms. Two days later I start blocking off injectors at the rail to eliminate injectors 1 by 1. No change with #1 blocked, seemed to want to fire a little more with #2 blocked. Fired and idled rough with #3 blocked billowing white smoke. So I'm thinking possibly 2 and 3 are bad. Reinstall #3 injector line to verify and it fires and idles rough as before. I've got an OTC Evolve connected and rail pressure is showing between 6300 and 9500 psi. I push throttle about half inch and it sputter then revs and continued to rev to 3000rpm with throttle released to at which point I killed the key. Just to verify I restart, it idles rough with lots of white smoke as before, bump throttle and it runs away again until I shut off key. I now notice oil all over behind truck and dripping from tailpipe, check the oil and it is halfway down on the dipstick. Pull intake horn and no oil, remove turbo inlet and no oil. Pull exhaust manifold back and #1 is dry, 2 through 6 are oily with 6 appearing worst. I assume 2 is the culprit and the oil is just running down hill in the manifold to the other ports. I just wanted to get some opinions before I proceed to pull the head. Anything else I should be doing/checking before I dig in that far? I'm thinking a cracked head? Melted piston? Maybe broken ring? I can't think of any other way for oil to be pumping through the cylinder. Sorry for such a long first post but I wanted to make sure you had all the possible info. Thanks in advance for any help and/or suggestions.

I ended up getting an endoscope, took #2, 3, 4 injectors out. I skipped #1 since it's exhaust port was dry. Stuck the camera down the injector holes and #2 is melted, looks like lava all over the top. # 3 and 4 appear to have holes in them. 3 off to the edge of the piston at the cylinder wall junction and 4 just off center of the piston. Let my buddy know and he's gonna start saving for a reman engine.