Could it be a thermostat that is bad? We just got home last night pulling right under 14000 in high 80 degree temps my oil never moved above 212. Did you aux fan kick on? Unless you are blasting tunes you will usually hear it. I agree with the above I assume the truck is defusing to protect itself. Although my tuned 6.4 would throw a green wrench until I pulled over and shut her down and restarted the engine. Hope you get it fixed soon. You will be amazed when she is working correctly how well it pulls. I pulled I 80 thru pa and was amazed how little pedal it need climbing mountains.
Gdlk
STM

 

I had no radio on, didn't hear any fan turn on. This morning, no trailer, 68 degrees out, temp got up to 215 before I exited for work just 8-10 miles from home. Awaiting dealership to call me back, I relayed all my info to service guy first thing this am.

 

I'm puzzled on this one. You would think the fan would kick on with all your temps that high. That's why I wonder if it is a thermostat I don't know how your oil could reach 215 that quick with no load.
Keep us posted
Sean

 

Remember that there is no thermostat for the oil cooler, just for the primary cooling loop. The cooling fan can cone on to cool down the cooling system, but if the temps are normal this will do absolutely nothing for the oil temps. That's why the cooling fan isn't coming on.

You can have scalding hot oil temps with perfectly normal coolant temps. This happens with a failed oil cooler.

 

Well that explains it. Looking forward to finding out this cause and the op getting to enjoy his truck
Sean

 

Every now and then something comes along to pique my curiosity - this is another case. I'm sure there's a perfectly logical solution, but it escapes me right now. I look forward to the outcome and rest assured, the truck will pull that load just fine.

 

I know its bad to speculate, but as the Oil Cooler is really 100% mechanical, and I think passive (oil passes thru it).. what could cause it to not do its job? short of an obstruction?

OR, is the sensor bad (reading too high)? What is the water temp when the oil temp is so high? It should be rising too..

Sam

 

Well, dealership was true to their word, (hard to find nowadays) and came across the valley even though truck had already been checked out ok as there were no error codes. Brian hooked up his stuff and away we went. In about the same location as before, oil hit 270, truck "derated" itself and slowed. Never threw a code. Truck is back at dealership as Brians computer said oil cooler and once he identifies it to Ford, they'll want all parts he takes off he said. Truck ran at 244 temp to dealership and I took photos and showed them.

 

As long as they fix your truck, Ford wanting the parts is a good thing.

 

Wonderful to find a dealer like this!

Sam

 

Although these are completely different examples, this is the common mode of failure for the oil coolers on the 6.4L and 6.0L trucks. Most blame it on residual casting sand left over in the coolant passages, eventually there is buildup that will completely plug the coolant passages in the oil cooler. On a 6.0L truck, which is plumbed in series with the EGR cooler, such a failure will starve the EGR cooler of oil and cause this to go bad as well. The 6.4L has it plumbed in parallel which prevents a bad oil cooler from destroying the EGR cooler.

 

Not to pick but the EGR cooler on a 6.0 never had any oil running thru it. I think you meant to say the casting would plug the oil cooler and not allow coolant to flow from the oil cooler to the EGR cooler.

 

Wow, this is really an interesting thread. I hope your truck gets fixed soon, I'm anxious to find out the cause of the problem. When it's all is fixed you'll be a happy driver pulling the 5th wheel. To bad this happened to you, but we all are learning something to file in our memory banks if we see this situation with our trucks.

Hope the truck is fixed to your satisfaction in the NEAR future!!!

Jim

 

I guess everyone should do a quick check to see where their temps are even without a load. Got my call today, parts of course are special order and s/be there by Friday they said, but that they'll be inspecting a few things so they can report it up the chain. So, will maybe get it back next week.

 

You're exactly right; I was typing that one out on my phone and in too much of a hurry. Of course oil doesn't go through the EGR coolers, I was thinking of coolant and got mixed up.

Thanks for the correction!