What is going on??

[Frank246]

Here goes a long question:
I have a 2015 ED with 90K miles on it. Tuned since 27K miles.
My normal temp for water/oil is around 204/208 respectively.
When pulling my TT of about 7000 LBs., it goes up to 215/220. Transmission is always around 190.

I have pulled my TT throughout the US and even traveled the Rockies/Grand Tetons/Glacier NP and in doing so, the water/oil temp delta is usually around 5-8 degrees F.

This weekend I pulled the TT for a 2.5 hour trip and the water/oil delta jumped to as much as 25 degrees difference.
I see what appears to be the water thermostat open as usual around the 201 mark and then drop back before climbing up as usual.

What I don't understand is what is changed to cause a normal 5-8 degree delta to go to as much as 25 degree delta.

Anyone with an idea as to what is going on?

PS: Have not lost any coolant over the past 5 years since I purchase it used in 2018.

Thanks in adv for any insight.

 

[Frank246]

OK, I guess no one has seen this before but lets try this:
How much of a delta do you who pull TT see between the water and oil temp as a norm?

I'm trying to figure out if maybe it's just old antifreeze or a thermostat or a clogged hose or ????

Thanks

 

[Rampage Roommate]

Could your thermostat be sticking?

 

[Frank246]

That was my first guess but I see it open at about 200 degrees and drop back to around 193 before climbing back up to a temp that used to be within 3-5 degrees of the oil temperature and is now a delta of as much as 25 degrees.
Certainly something has changed and it may well be the thermostat but I’m just trying to see if there might be any other issue before I jump in to “fix”.
Thanks again for the help

 

[1shadowsabre]

Well I read your post and am trying to remember what the differences are towing with my 2015.
It seems to me that just driving around my coolant and oil temperatures are pretty close to each other but towing my coolant temperature is higher. I am not sure it is 25 degrees though....

 

[Frank246]

Okay and thanks
I guess I’ll just need to keep a very close eye on it and see what happens.

Love my truck but as we all know it does require a constant eye open for “challenges “
Thanks again