Hey y'all. Figured i visited this forum as a guest enough times that now it is time to become a part of the family. I am a certified hd diesel mechanic with several years working for Cummins. I have access to all manuals and specs. If there is anything you want to know about how your engine is supose to work or how it goes back together feel free to ask.

 

Ever see a 12 valve push 1+ gallon of oil out the breather? EGTs got pretty high for 10-15 seconds or so I think, maybe 1700 degrees at the manifold.

It freaked me out, I started tearing into it before trying to locate compression/leakdown gauges so no I don't know...

Head is off, pistons look pretty good, no melting, no pitting, no nothing really. Cylinder walls look pretty good, cross hatching is still pretty obvious, but I can see vertical lines here and there - not scratches you can feel though.

I haven't yet pulled the motor out, too busy with fixing other people's stuff, but I'm leaning toward rings. The head looks pretty good too. I haven't found anything that stands out as being a source of major crankcase pressure.

 

Without actually seeing it its hard to really diagnose. If it happened all of a sudden i would suspect it to be your turbo oil seal. If its come on gradually it could be rings, valve guide seals or even the headgasket blew out into an oil passage. Best of luck.

 

Hmm. Is there an easy way to test the oil seal?

There's actually a little more to it - I was following an older 5.0 up I-5 and he got on it, so I rolled into the throttle (50-80ish) before I remembered to check my EGTs, which were in the 1700 rage iirc, so I lifted off the throttle and the engine died like I turned the key off. After coasting to the shoulder, I took a quick peak behind me to see if there was a trail of connecting rods and oil - nothing obvious so I fired it right back up and drove to the gas station right off the freeway and took a peak underneath, which is when I noticed the oil coating everything from the breather tube back.

Since it started right up and ran, I drove it home. The next morning it cranked over but seemed a bit more cold blooded than normal and behaved like it lost fuel system prime, stalled when I put it in gear, then restarted and ran fine until I rolled into the throttle in OD lockup on the freeway and lifted - stalled again but restarted without having to pull over.

I could get it to repeat the stalling by loading it up with the torque converter locked, then lifting off the throttle.

 

The way we check turbo oil seals is to remove the turbo oil drain from the block and put it into a bucket. Then add extra oil since you will be loosing the oil out of the turbo and it wont be draining back into the pan. Plug the hole in the block that the drain was in then there is a special fitting that will go into the breather hose that then goes to a water manomoner. Then do a stall test. So not really an "easy way"
Also sounds like you may have a fuel system problem.
Thats what happens when you try to race a ford. I normally just let em roll on by and then tow em off the road when they blow up.