ISX 600: Trouble in paradise

[Rocky]

Well. I may have to wear that badge and cross that bridge perhaps sooner than later. I'm fighting a low oil pressure issue as we speak that I believe is still related to my original post on this thread but now with a "proper" program. I started having oil temp issues literally a day after a PM at Loves. Oil, oil filter, fuel filter, lube, and inspection. Seemed harmless enough. I run T6 15w40 full synthetic.

I got the new programing. Truck runs and sounds like it is supposed to now. Fuel milage improved. I do slightly roll coal if I punch it any more than half throttle after changing gears. From a cold start the engine acts and sounds like its cammed and shakes the truck a bit until 130f or so.

The same week I started experiencing low oil pressures. 24-26 psi highway. 10-12 psi idle after reaching operation temperatures. Until then 35 psi and 20 psi

The following day I got the first instance of the dreaded red stop engine light and oil pressure gauge reading 0 psi. I pulled over immediately of course thinking I had lost all my oil. Checked it. It was full. OVER full actually. The truck sounded and ran normally even though the gauge was reading 0 psi when I started it after checking the oil.

Unplugged the pressure sensor and discovered oil in the connector. Tried cleaning the sensor, bending the tabs for a better contact but never could get it to communicate properly. After some time I decided it was a false reading. I left the sensor unplugged to calm the CPU and got the truck home. Truck ran, pulled, sounded, and idled normally. It still does even though I have yet to find the root of this issue.

I've since replaced the oil filter, and both the oil pressure and temperature sensors. No dice. Confirmed through Insite that the CPU is reporting the same PSI as the gauge eliminating a faulty gauge. Replaced the pressure sensor connector (pigtail). No change. I can say that I haven't had oil temperatures over 230f at 80k and pulling hills since.

Today I discovered that the oil used at the Loves from my PM was 5w40 and not 15w40. I understand that the second number is the same and should not affect operating temperature viscosity.

Tomorrow I will have the new updated pressure relief valve for the filter housing to swap out. I have also ordered an oil pump, shim kit, and oil pan gasket considering it looks like I'll need them either way.

The strange thing is. The truck idles smooth, sounds good, runs strong, and pulls good. This makes me really question the reading it is getting even though those parts are new. I'll will be acquiring a mechanical pressure gauge this weekend and trying to learn where I can jack into the motor to get readings to compare.

I don't want to be pessimistic but my goose may already be cooked. I don't know what else to do. Running the truck during the week and trying to research, identify and order parts; hoping they arrive by the time I get back so I can fix it on weekends. Oh, the joys of being a truck driver.