I use this site all the time but don't often post. I'm searching for some answers to our problem child... a 2011 F250 XL that we use in our remodeling business and for trips on weekends.
Sorry in advance for the long story!
We purchased the truck used last year. It's a fairly bare-bones crew cab previously owned by an oil company. It was used in Pennsylvania its entire life and had excellent maintenance records with it. The truck has 133k miles, but over 7,500 hours. It spent a lot of time idling on the sites, I guess. I didn't check the hour meter before I'd bought the truck... hindsight is 20:20.
Anyway... here's the problem. On one of our first trips pulling a 10k camper at 65mph, the engine seemed to start cutting back. Ambient temp was around 85* with A/C running full blast. We used a cheap O'Reilly Bosch CEL scanner and determined the oil temp was 255*. (I have the basic message center, so couldn't track oil temp via the dash.) There were no CELs or warning lights of any kind.
We slowed down a bit and once the oil dropped below around 250* the power came back. I think it was defueling on me. Coolant temp was 192* and never exceeded 194* at any point in the trip. Never heard the fan kick in either.
The whole trip went this way. I made myself pull over and idle awhile each time it exceeded 240*, so we didn't blow anything. At the time, I did not have a tuner or gauges in the truck.
Given my prodigious experience with 6.0s (due to our other work truck.
), I immediately assumed a plugged cooler and was also told by a dealership mechanic that that would solve the problem. We replaced the oil cooler and coolant once we got back from the trip.
We had planned a DPF delete, pyro, and tuner, so we did that as well. We replaced the oil temp sensor too, just for good measure.
However, the temps still crept north of 240* easily, whenever we pulled. And it didn't take much weight either. I was told by my cousin (a diesel tech professor at a community college) that the new cooler may be plugged from old debris in the system, so flush and replace again...
So... we just got it back from the dealership with a flush, new coolant, and new cooler. But still, even at ambient temps in the 20s, we get oil temps 240+ without working the truck too hard. And that's right after a fresh flush and fill!
The oil temp and coolant temp read the same when it's started cold after sitting overnight. Once started and driving, the temps rise slowly together, with the oil staying a couple degrees ahead of the coolant. Once the coolant reaches full temperature, the oil keeps on rising till we either back off or the motor defuels. This takes around a half hour of steady driving. (FYI: We pull trailers strictly on the "stock" tuner setting, and NEVER use the higher ones when we have a load.)
- 2011 F250 6.7L
- Built 12/10 (I think)
-7.5k hours (spent WAY too much time idling while out on refinery/drilling sites, apparently)
-10W-30 Motorcraft Oil
-Ford Orange coolant
-Replaced EGR Cooler Core (plugged due to the excessive idle time)
H&S MiniMaxx Tuner, Pyro, DPF Delete, EGR cooler & ducting is intact but disabled
I heard on a forum somewhere that these things have a "restrictor" in the upper oil pan that can dislodge and block oil flow to the cooler, but no mechanic I talked to has ever heard of that. I've also heard about faulty water pumps or front covers, but the engine itself seems to stay very cool. Any thoughts are appreciated!