Ok, I was finally able to get around to rebuilding my Ď66 5000 SOS. New crankshaft and everything. New oil pump. After I got it all together, it started fine. After checking for leaks and seeing none, I ran it for a few hours to get her warmed up good. Next day I ran it again for a few hours doing some loader work. Over the next couple days, I used it a few times but not for more than 30 at a time. This morning I started it up and after a couple minutes I saw smoke coming out oil filler cap. Immediately shut it down. Waited a half the day, restarted and moved back into barn and smoke again. I attached an aftermarket oil pressure gauge before moving back to barn and it never budged the gauge.
What could have happened? Like I said, it ran for hours no problem over a few days, and all the sudden no oil pressure. When I took the plug out from the block for the pressure gauge, it did not look like oil even got to it.