I have a 1999 F-150 with a 4.6 liter. First I'll say I luv it.


When towing even an empty 16' utility trailer she wants to run hot. It won't redline, but gets close.


When the truck isn't pulling all seems well. I do take it out of OD under a load.

Has anyone had this experience?

 

...Welcome to Ford Truck Enthusiasts!

See you on the boards. ….

 

Check your fan clutch first.

When towing (almost anything), the transmission generates a lot more heat. The heat is transferred to the radiator due to its inclusion in the transmission cooling loop. If the fan clutch is not working well, the extra heat cannot be rejected from the radiator.

Additional things to consider is the condition of the coolant and the internals of the cooling system. If it were my truck, I'd do the following as preventative maintenance:

Flush cooling system with a cleaner intended to remove corrosion buildup.
Replace thermostat.
Check condition of hoses and replace as needed.
Refill with proper mix of coolant
Replace radiator cap
Check belt and replace if needed
Install an external tranny cooler if towing will be in the future and none is installed.
Replace fan clutch if its weak.
Upgrade to e-fans if you want to.

Steve

 

Thanks Steve

Thanks for your input.......I will follow each suggestion ...........getting new clutch and belt t-marr .......will search for the rad cleaner and a new cap ..............of course new coolant ........