hey guys. when im driving down the highway 65-70ish the thermostat gos up normal all the way up to 240 ish and then the thermostat opens and it cools. it used to never move after it came back down to the middle line. now it is rising up above where the juice monitor can read it and it will just keep going so i start to slow down. id estimate it gets up to 220+. THE TRUCK EVEN SMELLS HOT. the truck runs great with good boost and even the egts seem under control. plus the temps here are touching if not going over 100 degrees. all opinions are welcome. thanks, john

 

When I had a ranger it did the same thing even in the mornings when it was cold, changed the thermostat aqnd it was fine. May not be the same issue but id say try that first. With the ranger the thermostat was old and was sticking closed and would hit the red and then it'd pop open and my temp would drop quick

 

im fine with it getting warm then opening its after the thermostat opens and then the temp gos up that i get a little scared.

 

replace ur thermostat mine would go up to 210 then the thermostat would open and go back to normal quick easy fix and cheap i would replace the thermostat and go from there

 

check your rad make sure the fins arent clogged

 

Replace the thermostat, steam out your radiator, and i would put some Royal Purple Purple Ice coolant additive and water pump seal conditioner. That stuff works pretty well.

 

yeah ill have to look at those fins. ive seen that royal purple radiator stuff but you are the first guy i have found that has used it. ill go read the bottle do some research.

 

check fan clutch as well

 

Im betting your rad is clogged from the blowby collector right on the front of the motor. Mine was! I relocated the bottle and cleaned the rad and no issues after that.