Truck is virtually stock, 166k on it, not studded. I replaced the oil cooler with an OEM last summer, less than 3,000 miles ago. (don't drive the truck a whole lot). In this scenerio, it was 60deg outside. I'm pulling a 12k# 5th wheel on the interstate. I have the SCT X4 with the canned 65HP tune currently loaded in the truck. I ran a data log for 36 minutes while mostly on the interstate. Here are some of my numbers:

Coolant temp min 188, max 204, avg 195.20
EOT min 209.44, max 245.75, avg 238.65
Engine load min 0, max 95.64, avg 51.73
RPM min 1522.75, max 2485, avg 2107
Vehicle Speed min 62.51, max 71.12, avg 66.63

As you can see, I didn't push the truck hard at all. It was pulling like a dream, couldn't have been happier. But with that new oil cooler, that EOT seems crazy high to me. I'm worried what it will look like when it's mid July and I'm pulling this camper through the WV mountains. Maybe I'm over reacting. I just need to some better more knowledgeable opinions .

I have the whole data log file (obviously) if it would help someone to see it.

 

Do the EOT and ECT read the same, or close, after a cold soak?
Let it sit overnight or long enough that the engine is down to ambient temps, then see what you have for readings.

That is pushing it on the EOT's I'm afraid if those are actual temps. She will start to defuel around 253* in an effort to cool down.
That is a high temp spread

 

Even your max coolant temp and minimum EOT are a bit far apart, 10 degrees apart or less is ideal, anything close to 15 and it's time to start replacing stuff from what I've learned.
On that note, how far apart should EOT and ECT be when cold? I've noticed when I go to start mine in the AM after sitting for approximately 12 hours, my oil temps are always cooler than coolant temps, sometimes as much as 20-25 degrees.

 

What coolant are you using?

Who did you buy the oil cooler from?

 

You should not see more than a degree or two after a true cold soak, so if you are seeing that high a spread it's likely not been sitting long enough.
I think the rule of thumb is 24 hours.

 

When it's cold, or even when I got off the interstate and into my town, the two temps sync right up. The few times I watched the temps, I've seen that 10-15 gap and kinda expected that this time around.

The oil cooler came from Ford. I don't recall the brand of coolant off the top of my head, but it's from Napa, same specs that the truck requires, or so my diesel mechanic buddy told me.

 

There were times where I would be watching the EOT and it would go from 240 to like 200. Almost like a thermostat would open and let cooler oil in. Very strange. I don't understand how this system totally works. Maybe I have a clog some where?

 

I wonder if the bypass valve is sticking open, not allowing enough oil through the cooler........I really can't say though if it would make that large a spread.

Hoping someone else might chime in. I know you can get just the valve, but it's a treat to change since it sits at the bottom of the filter housing.

Seems there as a thread on this subject some time back IIRC

 

I'll have to do some more digging around then. I sure appreciate you coming back and commenting!

 

I keep wanting someone to come back and say if it worked or not, we've only had one report that I can remember and the final post was something like "didn't fix it" and nothing ever again.

A similar one started two days ago:
https://www.ford-trucks.com/forums/1...ng-issues.html

 

I hear you Bryan, nothing more frustrating than unresolved threads. Seems there as one here over a year ago, the guy that has the sweet looking Ex with the 2011 and up front end conversion, was having issues with this IIRC.

That thread you linked is an interesting one as well.

 

The OP is pulling 12K # and running a tune so IMHO the standard Ford test spread numbers become less meaningful. . I agree the max oil temps in that range have to be watched closely.. When I get to 140 EOT heavily loaded and working the bejezzus out of my motor I get a little antsy, but I'd only really worry if my oil temps didn't recover fairly quickly after the summi (ie, the oil cooler is doing its job). The OP said he gets lower numbers fairly quickly, but the description left some question about recovery vs erratic readings. I would be interested in seeing what kind of numbers he gets when it comes up to operating temp, is unloaded, and on the level at 65 mph.

If the truck has been running Ford Gold at those temperatures, you can almost guarantee there has been silicate drop-out and clogging of that newish cooler is going to be underway.

 

Good post man, thank you. I will try to get out on the interstate today with the truck unloaded and run a similar test with that same tune and report back. Can't promise it tho.

I'll also find out what coolant I'm running...bugging me that I can't recall it.

 

That is very frustrating. I'll certainly be posting back with my results as i find them once we get this thing figured out.

 

What numbers do you see without the tune?
Are you monitoring your EGT's?

I would not be comfortable running that tune not studded with no means to check the EGT's towing those #'s