Notices
EcoBoost (all engine sizes) 3.5L Twin Turbo EcoBoost V6, 2.7 Twin Turbo EcoBoost V6, 2.3l/2.0L I4 EcoBoost Engines

3.5 running hot while towing?

Thread Tools
 
Search this Thread
 
Old Aug 23, 2023 | 02:35 PM
  #1  
JWorley's Avatar
JWorley
Thread Starter
|
Mountain Pass
Photogenic
Photoriffic
Shutterbug
Liked
Joined: Jul 2023
Posts: 109
Likes: 37
3.5 running hot while towing?

2019 F-150 4x4 3.5 200k miles is running hot towing a trailer at interstate speeds(utility trailer with utv). Going 55-60 it runs normal, 65-75 it goes to the top of the gauge especially on long grades. Started on a trip from South Georgia to Illinois this morning and didn’t make it 50 miles before turning around and going home. I changed the thermostat, didn’t help. Radiator is clear, no CEL light everything else seems fine. I’ve towed the same load with it for thousands of miles and never had a problem until now.
Anybody got any ideas? If I could get this straightened out fast I would still have time for my trip.


 
Reply
Old Aug 23, 2023 | 04:14 PM
  #2  
BC2019F250's Avatar
BC2019F250
More Turbo
5 Year Member
Liked
Loved
Community Favorite
Joined: Sep 2019
Posts: 579
Likes: 332
From: Southwest Michigan
What are you considering normal or hot?
 
Reply
Old Aug 23, 2023 | 04:25 PM
  #3  
JWorley's Avatar
JWorley
Thread Starter
|
Mountain Pass
Photogenic
Photoriffic
Shutterbug
Liked
Joined: Jul 2023
Posts: 109
Likes: 37
Normal is about midway of the gauge, where it stays around most all the time, hot is getting in the red. On an uphill grade it’ll start steady climbing until it derates and flashes “power reduced to lower temperature” or something to that effect.
using tow/haul mode
It did the same on the interstate Monday with just the trailer. I stopped to check the coolant, it was a little low, topped it off, drove the rest of the way home off the interstate with no problems. Yesterday I drove all over with a moderate load in the bed at interstate speed’s with no problem and I drove it with and without tow/haul mode on, the gauge stayed around midway the whole time so I wrongly assumed I would be good to go this morning.
 
Reply
Old Aug 23, 2023 | 06:14 PM
  #4  
85e150's Avatar
85e150
Super Moderator
20 Year Member
Community Builder
Liked
Community Favorite
Joined: Apr 2004
Posts: 34,534
Likes: 2,835
Club FTE Gold Member
--Belt slipping resulting in slow water pump drive. Are you having any charging issues?

--water pump worn to the point of being inadequte for high heat loads.

--head gasket going pushing super heated combustion gases into the coolant under load. Does the coolant have a rainbow on it or is it gray with bubbles?

--you had low coolant--where is it going?

--are your radiator shutters working correctly?

--electric fan in good shape if equipped?



 
Reply
Old Aug 23, 2023 | 06:31 PM
  #5  
JWorley's Avatar
JWorley
Thread Starter
|
Mountain Pass
Photogenic
Photoriffic
Shutterbug
Liked
Joined: Jul 2023
Posts: 109
Likes: 37
Originally Posted by 85e150
--Belt slipping resulting in slow water pump drive. Are you having any charging issues?

--water pump worn to the point of being inadequte for high heat loads.

--head gasket going pushing super heated combustion gases into the coolant under load. Does the coolant have a rainbow on it or is it gray with bubbles?

--you had low coolant--where is it going?

--are your radiator shutters working correctly?

--electric fan in good shape if equipped?
charging seems fine
don’t know about water pump vanes
coolant looks good no bubbles or oily residue
​​​​​​ don’t know where the coolant went, can’t see any leaks, don’t really know how long it was low, took 3/4 of gallon to get to max fill. It was still on max this morning.
Radiator shutters are open sitting still
​​​​​​ I can see through the radiator with a flashlight ​​​​​
 
Reply
Old Aug 24, 2023 | 08:15 PM
  #6  
JWorley's Avatar
JWorley
Thread Starter
|
Mountain Pass
Photogenic
Photoriffic
Shutterbug
Liked
Joined: Jul 2023
Posts: 109
Likes: 37
Ok so, if anyone else has this problem, wash your radiator coils out thoroughly.
I looked through mine with a flashlight and could see through them well but, this thing has a tiny radiator that evidently can’t stand much of a restriction. I’m used to dealing with much larger radiators that have way more stuff in them and still don’t have overheating issues.
I took the plastic cover between the grill and radiator off to expose it and the ac condenser, then removed the bolts from the fan assembly so it could be tilted back. I used compressed air first then water. There was a few bugs in there, a few feathers and some plant parts, it didn’t look like much but was enough. I washed it out as well as I could. I’ve been about 250 miles now at 75mph with no problems.
Maybe that will help somebody.
edit- just went over Mont Eagle with no overheating so, it’s good.
 
Reply
Old Nov 12, 2023 | 04:36 PM
  #7  
craftsmangary's Avatar
craftsmangary
More Turbo
15 Year Member
Liked
Loved
Community Favorite
Joined: Jun 2009
Posts: 580
Likes: 58
From: Michigan
Clean the front of the radiator/cooling stack, it has debris on it, I see it often.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
99FordDually
1999 - 2016 Super Duty
5
Sep 4, 2021 08:18 AM
99FordDually
1997 - 2003 F150
2
Aug 30, 2021 01:17 PM
1984F150_300-6
Ford Inline Six, 200, 250, 4.9L / 300
8
Sep 17, 2018 09:12 PM
Rafiki2cu
6.7L Power Stroke Diesel
11
Sep 23, 2010 09:12 PM
RUNVS
All Things Towing
8
Jan 15, 2010 01:36 PM




All times are GMT -5. The time now is 06:13 AM.

story-0
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-1
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-2
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-3
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-4
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-5
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-6
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-7
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-8
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-9
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE