Fuel in engine oil

[cesar034]

Good evening everyone, I wanted to throw this out there to see if anyone has experienced this and could offer any insight. A little back story, 2 months ago I had a Cummins cm871 head was installed last year in may and around end of February It began mixing fuel into the oil. Tested various things and found that when I applied air pressure to the front bank timing port it would push air out of the injector cylinder 3, it looked to be leaking from the seals. New seals were installed and found the same result. We swapped the injector on cylinder 3 with a Cummins one and it kept doing the same thing. We sent all the info over to the manufacturer along with the cylinder head and after they tested it told us nothing was wrong with cylinder head. We installed a new head and the issue was resolved. Fast forward to now and different customer is experiencing the same issue they installed the cylinder head in June of last year from the same manufacturer of the previously explained cylinder head. Customer complained of the same issue fuel in oil and so the same tests were conducted and found the same cylinder, number 3 leaking air from around the injector when the timing port was pressurized. Cylinder head still under warranty but I believe if we send it back into warranty it will get denied once again. Has anyone experienced something like this or have any other advice? New seals and a new injector was installed on this cylinder head and same result.