I have a 480 ck with a 4 cylinder diesel I have been getting fuel in the crankcase oil. I suspected the injection pump seal and started taking parts off for removal . when I removed the valve cover I found both # 3 cylinder push rods bent. I am inclined now to believe the IP was not the problem and perhaps the injector was dumping fuel caused a hydo lock and bent the rods. Where do I go from here. I am thinking replace rods and do compression test as cylinder is now washed. I may have to replace rings . If i have to pull head and pan I will do all 4.
That's where I'd start.. take ALL the injectors in for testing.. TELL THEM your looking for 1 stuck open.. if they find 1.. replace ALL 4.. All the inj. had the same fuel run thru them and have the same amount of hrs.. Replace the push rods and do a compression check.. the compr. test will show you whats next.. A stuck open injector should have showed up with HEAVY BLACK or WHITE smoke.. and the engine should have skipped .. BAD.. Don't rule out the pump as a cause for the oil dilution.. Good luck.. TPG
Unless this problem has been going on for a very long time I would not worry about rings at this time. Did the engine turn over good the last times it was started? A hydro locked engine would crank over a partial turn then stop dead or at least hesitate before turning any further. If you check compression and one cylinder is low I'd be pulling the pan and at least look at the rods to see if one is bent.