I am getting a reduce power message when towing an empty 12’ Utility trailer. Had the same issue 2 years ago when the truck was under warranty. They changed water pump and thermostat and said all is good. I don’t tow much at all but went to pickup and new quad yesterday and running on the Highway empty trailer the message popped up. The trans temp stays at 180 but coolant shows 230+ until deceleration. I’m suppose to heady to Colorado in a week towing two quads and need to iron this out asap. Any advice is appreciated.

2017 3.5 Ecoboost

 

What engine and year, care to share?
I would suspect the thermostat first and what is the coolant level before doing any work?

 

Not sure why my sig isn't showing. 2017 Ecoboost 3.5

 

I had this same issue going up hill towing a camper with AC on. I found the shutters were closed for some reason. I pulled most of them out on the side of the highway, and haven't had time to find the cause.

 

Are you out of your powertrain warranty coverage?
How long ago was the the thermometer and pump changed? Usually parts have an "extra warranty."
Does it say what part number they used for the thermostat, there is apparently a new one.

Depending on the answers to the above, since you actually had a recordable failure per the design of the truck (not just "kinda running hot") I would reach out to the dealer that did the work, tell them whats going on, explain that you believe there is an updated thermostat...depending on if you are still under powertrain or part install warranty, id have them change the thermo and flush the coolant...if they wont and you can do it, id do that....otherwise id push back to the dealer.

 

it was last September when the water pump and thermostat was swapped. Per the notes the water pump was changed after noticing a leak while doing the cam phaser repair and while it was there they checked the thermostat for my over heating. Notes state thermostat was replaced to fix that with hl3z-8575-b. I’ll call the dealer but doubt there’s much they’ll do unfortunately. It’s out of warranty now

 

youd be surprised, especially since it’s still technically less then a year.

I don’t know if that’s the new part # or not…I would also ask if they flushed the coolant. Either way, the new thermometer and a flush seems to fix when people are actually having overheats

 

When you have the thermostat replaced again, make sure they chemical flush the system, even if you have to pay for it. Also require the gold coolant. The orange coolant from 17-18 has caused a lot of cooling system issues including the one you are describing.
My thermostat looked almost like new on my 18. I never would have guessed it was the issue. Replacing it and the coolant and I can cruise down the highway when it is 90⁰F and the truck doesn't go above 220 - with 9k+ in tow!

 

Update, they called and said might be a blockage in the radiator. Flushing and seeing it they can find it. Said top and bottom hoses were vastly different temps.

 

shouldn’t the top and bottom hoses always be different temps?