u/Icy_Association_2331

6.7 Powerstroke Derate on inclines

Alright, I’m posting this here because I am completely stumped and I can find nothing on the internet that marches my symptoms

I have a 2017 6.7 F350 crew cab long bed. Love this truck

I have had a problem since I bought it where anytime I’m towing up a hill, my oil temps rise to around 230/235 and my coolant hits about 215/221.

I am not towing particularly heavy loads, maybe 6000 pounds but it’s always on a relatively steep incline. Today it was the inclines between Phoenix and Flagstaff.

As soon as my coolant hits 215ish, my engine derates and I lose power. I have nothing, fan kicks on but it gives me no power even when the temps do decrease. I usually have to pull over and wait a few minutes idling to allow the truck to cool down between 200 degrees for coolant before I take off and the same thing happens a few minutes later.

Initial thought was: oil cooler. So I replaced that with a BPD one. No improvement.

Bought a Mishimoto radiator. No improvement.

Bought one of those gimmick heat sink oil pans. No improvement.

The kicker is, I had a catastrophic failure several months ago where road debris destroyed my oil filter, I lost all my oil, and by the time I noticed I had a spun main bearing. So the engine was replaced and in doing so I also deleted the DPF and I have a mild tune on it.

But I’ve had the same issue with derating before and after the tune/delete.

I have absolutely no idea what the issue could be. I am constantly getting passed by similar trucks with heavier loads, I can’t explain why I’m having these issues.

Anyone have any thoughts?

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u/Icy_Association_2331 — 4 days ago