Going through a nightmare situation with my 95 7.3
The truck's a 95 with 304k.
Ok so all of this started back in January when i went to put a new seal kit on my engine oil cooler. I removed the cooler and replaced the o rings. Fill the truck back up with coolant and oil and start her up. She ran for about 10 minutes then started idling rough and died. Started her back up and she ran for 5 seconds then died. Started her back up and she died again immediately. Would not start after that. No check engine light. (Oil level was good and she had fuel)
Initially i thought it was a fuel pump issue so i replaced it to no avail. From there i started reading into oil pressure problems (HPOP). I had a diesel tech from a shop come and run some tests. He said the HPOP wasnt working. Lucky for me a few months earlier i had picked up a 97 7.3l with 79k on it. The mechanic i took it to said to take the HPOP from the other motor and slap it in it. After having the shop switch them out the truck ran great aside from no oil pressure reading on the dash gauge, which i thought was weird. On a cold start the gauge would read correctly then back down to nothing after warmed up. Only when i was at 2200 rpms would the gauge move to normal then back down again. 4 days after running it i went to start it and she wouldnt start again. No oil pressure to open the injectors.
The guys from the shop tested the IPR and ICP and said both were working correctly. They opened up the top of the HPOP reseivor and put a gauge in to read the LPOP. Absolutely no low pressure. Went out and bought a brand new pump from International and had it put in. The truck ran good for 5 days but still no dash reading for oil pressure. I even switched the oil pressure switch. Was out one night with a buddy trying to pull him out and the truck quit again and wouldnt start. Same problem.
I went back to the shop and their finally diagnosis was the motors old beat and going. I finally said screw it and had arranged my friend who is a 7.3 wiz to drop the 97 motor i had in it. He switched everything over to the other motor and reassembled it all. Watched him start the truck and saw it ran fine. When he finished putting the front end back on the truck and went to back it out of the garage and she wouldnt start again! He put a gauge on it and sure enough no LPOP! He took the pump out and put the original LPOP that came out of the 97 back in it. Truck started up and he went no more than 100yds down the road and the check engine light came on and the truck died and wouldnt start back up. The code was for a bad ICP reading and he tested the LPOP again to find NO pressure what so ever!
This has been a 4 month production for me and no one seems to know whats wrong. Are we missing something? Everyone who has looked at the truck is absolutely baffled. I read on another forum that possibly the oil relieve/regulator valve in the oil filter housing got messed up causing the bad reading on the gauge and the low pressure oil problem?
SOMEBODY PLEASE HELP!