I can't buy the statement that CAT ELC coolant would run warmer.

Anyway, it sounds like a thermostat issue. You shouldn't be seeing that variability, or the high end on coolant temps.

 

There's no reason for it to defuel at 210 F. Towing and seeing higher ECTs is perfectly normal. If the bully dog is defueling at 210 F, than that is a problem.

With a stock fan clutch and 110 F weather and towing 12k LBS, I would be flat and level between 205, but when I went uphill it would hit 220 ECT, and the fan would come on screaming like a banshee and keep ECTs there, like the system is supposed to.

I noticed no difference between ELC and FOrd Gold for ECT.

 

Thanks for the feedback. Gonna go ahead and replace the thermostat. In hind sight, should have replaced it when I did the flush. Lesson learned.

As for the defueling issue, should I increase the temp threshold or shut if off all together?

 

the only reason for your operating coolant temp to change with new coolant is water cools better than coolant so maybe your old coolant was weak ?
if your setting the defule parameter then yes change it to a higher temp or shut it off

 

I still don't see the issue. Coolant hitting 214 while towing is nothing unusual.

 

Appreciate the feedback. Like I mentioned, I think my OCD was kicking in a bit as we moved to the X from a 2007 Esalade ESV where temps were always under 200F until it one it spiked to 219 and got milkshake in the oil filler tube. In any case I will go ahead and replace the thermostat. Currently at 186k on the mileage and since I am not the original owner I have no way of know if / when it was ever changed. I will also deactivate the de-fueling feature.

 

................................ "Water temps range from 176F-198F "

Personally, I wouldn't be happy with that variability (as I posted earlier). Why would it vary down below 190? Probably the thermostat. This is assuming that the OP really meant that it varied as low as 176 after the engine had fully "heated up".

Also, I tow 6k-8k without ever getting to 210, in some high heat. I am happy about that. A 6x12 MIGHT weigh in heavier than that when loaded, but probably not......unless tandem axle and w/ some heavy cargo (ie dual 7000 lb axles). I also acknowledge that I don't tow any steep grades. That said, I agree that 214*F isn't terribly high as far as engine safety goes.

The BullyDog tune might be causing it to run hotter than a stock tune would. You are supposed to run tow tunes when hauling a significant load.

 

................................ "Water temps range from 176F-198F "

Personally, I wouldn't be happy with that variability (as I posted earlier). Why would it vary down below 190? Probably the thermostat. This is assuming that the OP really meant that it varied as low as 176 after the engine had fully "heated up".

Also, I tow 6k-8k without ever getting to 210, in some high heat. I am happy about that. A 6x12 MIGHT weigh in heavier than that when loaded, but probably not......unless tandem axle and w/ some heavy cargo. I also acknowledge that I don't tow any steep grades. That said, I agree that 214*F isn't terribly high as far as engine safety goes.

The BullyDog tune might be causing it to run hotter than a stock tune would. You are supposed to run tow tunes when hauling a significant load.

Yeah, I am not happy with the variability. We'll see what happens with replacing the thermostat. You are correct about the reference to 176F.
Trailer is only single axle.

 

Whats the oil temp when coolant is 219? I didn't see if mentioned anyways and since you did a flush are closely monitoring the difference between coolant and oil? There are chances of flushes knocking stuff loose and clogging an oil cooler. so with 219 coolant temp id be curious what the oil was at the same time etc.

 

The 219F temps were on a different vehicle. The highest temp I saw on the X was 214F while going up a grade. I did not think to check the oil temp but have setup that monitoring now.

What is the lifespan of the oil cooler? Might be something else I need to replace.

 

Hi all,
Went for a good drive today to monitor Oil / Coolant temps. Various driving conditions....drove (not towing and speeds between 40-65 MPH) for close to an hour in total with a 1 hour break in between....oil temps peaked at 221 during the drive with coolant temps showing at 192. Ambient temps were 68-70F. Is a 29-30 degree delta acceptable between the two?

 

Uhmmm, no

 

I was afraid of that. Y'all recommend staying with the factory style oil cooler or moving to an external type?

 

That depends on how dirty your system might be. With a relatively clean system, an OEM oil cooler can do just fine. If the system is scaled up and full of silicate gel, then even extensive flushing might only break free more debris and that could clog up a new oil cooler.

IMO you need to do some investigative work on how dirty your coolant system is.

 

I still have the coolant from the flush in clear gallon jugs....there is a dark gray layer that has made it's way to the top of the jug. Has a very smooth almost slimy feel to it. Given the delta on the oil / coolant temps, I suspect some additional cleaning is needed.

 

That is likely to be oil floating on top of the coolant.