Which after market oil cooler has worked the best for a 6.0 . This engine has been plagued with HPOP failures. The truck is a 2003 F550 crew cab, dually
The egr delete has been done and there has never been a chip or programmer on it. It is used to move my RV a couple times a year usually short trips and for work and home about 25-50 miles a day five days a week. Ran great and all at once will not even attempt to start unless ya give some start fluid. The last HPOP the oil cooler was replaced, however may replace again with a hopefully better one.

 

Can u get scanner on it and check desired vs actual high pressure oil? I was always told the updated factory cooler was best and my stock one is still in my truck. I did get DieselSite adrenaline pump when my old one wouldn't build enough pressure, but I got over 210,000 on stock original pump. I'm keeping my truck for a long time unless I hit lottery big time!

 

if your going to keep your truck I would go with a BP oil cooler kit and get rid of the factory cooler.
I did this and it works great, 90-95 temps outside>> cruise set at 72 with air on no load, w-temp 192, oil-temp 188-190, slow doen and get off highway oil temp goes up to around 203-205 for a few minutes.
A little pricey but a quality kit