Hello
I have been searching the forums a little and trying to research an issue that I just started having today.
My truck was running hotter than normal. I noticed something different about a week ago. Going up a steep bridge without towing anything my truck got warm enough to open the thermostat. It was in the morning, in 50degree weather so it kinda concerned me. I noticed it again on another bridge so it wasn't just a coincidence. About 3 weeks ago I replaced that little flexible orange coolant hose, so I was kinda thinking it could be some air trapped. But it has been warm enough during the day to open the thermostat plenty and I haven't had any problems.
Today the weather was raining and cold so traffic sucked. I was in heavy stop and go traffic but the temp in right at 50, so plenty cool. My temp would run all the way all the way up to around the 210 mark and then slowly cool back down to what it normally runs around, the 190 mark. This problem occurred plenty on the 1 hour drive home. I noticed it get hot from a dead stop if I got to about 1/3 to 1/2 throttle.

Last night I took off the Smarty Jr and just reprogrammed it to stock. Is that just a coincidence? Any place to start? Thermostat? Fan clutch?

Also, no CEL.

 

replace the thermostat