I have a problem I have spent 2mo trying to fix. Back story: I bought a F450 and drove it 120mi to see my folks, when I pulled up I noticed a drip. I found a massive oil leak on the top of the engine, to the tune of 40 miles to the gallon of engine oil. Both the pedestal and HPOP orings were leaking so I replaced them and the leak stopped.

After replacing the orings I took it for a ~40mi drive when the drivers side bank stopped firing and left me on the side of the road. I pulled the valve covers and did the 50c mod. Split the loom off the harnesses and didnt see anything obvious. At that point I had to get a ride home and bought a ton of spare parts and AE.

I did the IDM continuity checks and it passed, AE said the driver side bank was open. I put a borrowed IDM in and it started right up and ran with no codes. After driving the 120mi home I gave the borrowed IDM back and got a reman. I put it on and it will pass a buzz test, but start the engine and it says 3 of the 4 drivers side cylinders are open. If you reset the codes it will again pass a buzz until you start the engine again. The SES light isnt constant, it comes and goes a couple times a minute.

It sounds fine to me, seems to have plenty of power and it idles smooth. I am going borrow a temp gun to shoot the exhaust manifold to confirm the cylinders are firing, but even when it is throwing codes it shows 0% on all of the perdels. I just replaced the drivers side UVCH and valve gasket, again with the 50c mod, with no change. I am temped to leave it alone, but dont want to get stranded on the way to work, not very many good places to break down.

I think the reman IDM is junk, but I can't send it off as my other truck was taken to the scrap yard today when it threw a rod so the PSD is my only vehicle at the moment. I haven't sent the old IDM back yet *sorry Riffraff, I will I swear*, it still says bank two is open and it had water in it when I cracked the case.

Im not a diesel mechanic by any stretch and would love some advice. I've only worked on two diesels, this one and one from a M35A2 I used to have. The White Multifuel was much easier to work on and got the same fuel econ as my F450, but running waste oil... And the same distance between stradings, the Deuce was at 11 and the F450 at 1. At least the ford as AC, power steering, and dual circuit brakes.

 

Update: Took the truck for a 10mi drive and shot the exhaust manifolds on both sides with a temp gun. I got roughly equal temps for both sides, all ports. I thought I had one that was low on the drivers side, but I had gotten some of the steering shaft in the beam, when I aimed better I got the same temp.

I think its a faulty IDM, that most likely won't hurt anything.

 

When I did the 140v IDM mod, I would occasionally get the P1298 code for IDM failure. I later went back to a stock 120v reman unit. I went through two remans that either weren't sealed properly or gave codes that never existed before. I checked the IDM wiring and found no faults. The third one they sent seems to work fine, but always throws the P1298 after doing the buzz test. I have tried the spare 110v IDM that I have while waiting for the remans to arrive and gotten no codes. I still don't know what's up with the remans. It kinda gotten me gun shy about trying another. For now, I'm leaving well enough alone.