My 01 CTD has always ran cool, 210 or less, regardless of the ambient temp or what I'm pulling. But lately, even with light loads and reasonable amb. temps it will run 225 and on a long hill pull close to 240. I have cleaned the condensor intercooler and radiator best i can without pulling them out. I ran the heat and windows down for 2 hrs yesterday pulling 2 jeeps to keep it in operating range at 70 mph.

The truck only has 145k on it. Egts rarely get to 1200 even on long hills with smarty on 7. My first thought is to pull the radiator. Any other ideas?? Thanks.

 

It looks clean but it isn't, especially if you still have the factory puke bottle in place, or haven't relocated the outlet for it. You really need to pull the rad to do it right.

Flush and replace fluid, check/replace thermostat is what I would do.

 

Um well Id say back down the skinny pedal a little, that is a fairly decent load your pulling and 70mph can build allot of heat on long pulls especially if you have a auto that is slipping and scratching to get to the top. I don't know what smarty setting 7 is as I run a quadzillia but maybe find a less aggressive more timing less fueling program made for towing?

I would also like mention get the radiator and condenser in inner-cooler pulled out and flush the radiator,then relocate the bottle to the garbage and run a longer hose on the crank case breather to just above the front axle.