Getting warm 2011 Cummins ISX on International prostar

yeah, if they are stuck open, you will be over cooling like in my situation which is what the problem you wish you were having right now I guess

 

A21CAV has the right idea; you even got a new ray gun thermometer, It' just like Science class all over!
Cheap insurance, and then you know exactly what's going on. Good luck. Keep us in the loop.

 

Please provide ESN. There were head gasket changes on the ISX over the years. Did you match the old to the new and check coolant flow ports to match? How long does it take to get to fan on temp while idling from cold start? What is the cycle time between fan on times while iding? The operation based on your description does seem like normal operation depending on the timeline to get up to temp and to fan on temp. I also agree this time of year it is difficult to get to fan on temp during colder weather with no load. Vacuum filing is necessary to be sure of no air pockets.

 

`Dont forget to pull your air cooler any from ft of rad enough to clean the ft of rad of all dirt an trash off back of a/c cond. and ft of air cooler then ft of rad you cant get air thru rad if air is blocked from whats in ft of it packed with dirt an trash, I have found w/mart plastic bags stuck in ft of rad in place that i could not think how it got in there?

 

What did the old radiator look like? Internally as well as externally. I would assume the engine fan was operating during the overheat issues? Sounds simple but make sure the fan is sucking and not blowing. Your symptoms are classic of poor air flow across the radiator. Your fan on time should be fairly short. Say 2 minutes or less from 210 down to 190. Your times seem in line to me. I say run it at this point and see how it acts. Unladen this should run down the road at thermostat temp with no issues. A good test that has always worked for me is to throw a red shop rag in front of the AC condenser/CAC to see how hard it sticks to the front. With the engine fan on and at rated RPM of course. Poor air flow and the rag will usually fall off or not stick hard.