6.0 Powerstroke High Pressure Oil Pump Leak Issue
I have been working on this pain in the butt 2006 Ford F350 6.0 turbo diesel for a week straight (time added up). Had a no start just crank, only started here and there after not being started for a while but once it warmed up and the oil thinned if you shut it off, it wouldnt start back up just crank. The computer narrowed it to not enough pressure so we changed the IPR Valve. Still wouldn't work. Found the video online about the STC fitting and took engine apart again to find that the STC fitting was actually bad and got the new replacement part and put it in. Put the engine back together and it started and ran. Let it run a while to warm up and shut it off. Cranked it again and it started. Did this about ten times and drove it etc. let air out. Guy drove it for a day and then to Providence RI. On way back the engine died on him. Had it towed back to us and it is cranking but no start. Back to square one. Did an air test to find any leaks around or in HPOP through the ICP. Saw no evidence of leaks from the stc fitting or around the HPOP. Was hearing a gurgling noise which sounded like it was coming from the pump. Took the pump out and did a air test through the system without the pump attached. No air noises or anything.
Really thinking it is the HPOP but wanted to do whatever i can to find out if anything else would be the issue before buying a new pump and installing and put it back together and find out it isnt the pump. I blacked off the IPR valve hole and the hole that the stc fitting is and the drain hole. That is only three holes which i see that oil goes in or out and should be blocked to do a air test into the HPOP itself to see if any leaks in the pump. When doing that air is coming out of a little hole that is in the HPOP behind the gear. Now it looks like it is meant to be there but doesnt connect or go to anything so i dont know why air would be coming out of there. if air is coming out then i would think oil is coming out. unless i am wrong like i said i dont know what that hole is.
my question is what is that hole in the back of the pump behind gear and should that have air coming out?
if it isnt i am presuming that it is definitely the HPOP.