I was using my 2024 F150 5.0 to pull our 4k lb travel trailer this weekend and I was closely monitoring the gauges to see how it would do. (Only 14k on the truck and haven't pulled the camper much.)
I was running ~65 mph and watched the coolant temp walk up to 210F, the trans temp went to 222F, and the oil temp go to 233F. This was really surprising that the 5.0 seemed to be struggling to keep temp in 70F weather with long rolling hills at the very worst. (North Mississippi)
I was looking for a place to pull off the road when my wife leaned up and hit the button to turn on the A/C because she felt "stuffy". I feared this would only make the situation worse and was about to turn it off as I frantically began looking for a place to pull off. However, I noticed the temps almost immediately begin to drop! The coolant temp went all the way down to 190F and the other two settled out at 201F.
I began experimenting by turning off the A/C and the temps would begin to climb shortly after. It would seem that the fans aren't coming on without the A/C on, but activating the A/C turns on the fans and cools it off quickly.
Thoughts? Troubleshooting recommendations?
It's under warranty and I can take it to the dealer, but this problem doesn't really show up until I'm towing. Daily driving keeps it at a more reasonable temp. \0/

 

Welcome to the forum. With it still being in warranty, I'd drop by the dealer and have them check it. May not find anything wrong with it but your concern will be documented should a related problem happen down the road.

 

Sounds like the AC automatically turns on radiator fans, vs waiting for the temp to call for them to turn on.

Your truck is fine. If you ever do get to an overheat situation, it will tell you and reduce power.

 

Makes me wonder if the AC being on opens the shutters? I agree there's probably nothing wrong with your truck. I'm not a fan of the shutters and leave them open in the summer, don't like the air to the intercooler being blocked-kinda defeats the purpose.

 

All of those temps are within operating limits. You're good.

 

I'd have to go back in my posts to see reported temps but I know I've seen 200 plus on transmission and that's ok. The truck has a fail safe limp mode if ever it see an over temp scenario.

I've towed in summer though NY, PA, VA plus the relatively flat land around the great lakes. Never had any cause for concern. AC on, up to 13k weight.....no problems. And you have the added advantage assuming you have the factory tow of 3.73 gearing. Engine cooling and transmission do exchange heat. Do yourself one favor. Check the coolant level. Mine from the factory was at or just below minimum. I added the right stuff from Ford and kept on trucking.

 

What gear were you towing in?

 

Good point, I rarely tow over 5K anymore but I still lock out the top couple gears on the highway.

 

All parameters were nominal. Water temp derate is 250 degrees, trans is over 260. Turning on the AC opened the grille shutters and turned on the fans.

 

I agree that the AC automatically turns the fans on, but don't think the truck should allow those other temps to get so high before turning the fans on.
The 210F coolant temp is borderline ok and the 233F oil temp isn't preferred, but 222F on a 10R60 transmission? That's a good way for Ford to sell more transmissions if you ask me.

I'll do some research to see if this is adjustable in Forscan.