ok.. both my tow rig AND Jeep are doing this. :(

When cruising at 60mph the Jeep and the Truck (while towing) will slowly get hotter. Running around town its fine, stop and go traffic the Jeep only occasionally gets warm but only 15 degrees above normal or so.

The radiators aren't blocked (same airflow as before)
The clutch fans on both are new

Nothing else has changed from last year or the year before, I didn't have the problem then. Any ideas on where to look? Does a flush help out any?

I can bring the temp down to normal by running the heater, so its just bad enough to be a nuisance.

Try having the radiator rodded out...sounds like your not getting enough coolant flow through the radiator at higher speeds..
make sure cap and thermostat are also in good working order

Thermostat on the tow rig is good. forgot about the cap, I'll just replace the sucker tonight. it probably has 100,000 miles on it.

sounds like rad needs rodding .. at that mileage it's probably a good thing to do anyway!
If it's a plastic tank rad...must replace it...can't rod them...some try..but don't..wont last...crimp on tank never holds

Originally posted by 1BDYJ
sounds like rad needs rodding .. at that mileage it's probably a good thing to do anyway!
If it's a plastic tank rad...must replace it...can't rod them...some try..but don't..wont last...crimp on tank never holds

If it comes down to that, the Tow rig is getting a 3-4 core radiator and the jeep is getting a 2+ core.

Don't know what models,engines both vehicles are....but you should run a 4 core in tow vehicle and a 2-3 row in jeep

Just a thought, is it hotter than it was last year outside? Could it be that you cooling systems are just barely adequate and the hotter outside temps could be the reason?

Sounds like you need to revamp your cooling systems..

No, it can do this on a 70 degree day, or even a 60 degree one if I am towing. (my tow rig anyway) These are OEM cooling systems for an OEM engine, etc. So something changed or wore out.

I swapped out the cap this morning, I drive out to yakima this weekend so I'll know if it got better or not. there are some steep grades with 90-100 degree temperatures I'll be pulling. w/ the AC on of course.