Engine temp control

[getblown5.9]

My mega cab 5.9 has 237K miles on it, and while idling last night in 68-70* ambient air temps, my Edge juice monitor kept alerting me that engine temp was over 210*. It would hit 212* and then slowly drop down to 187* then climb again.

I am assuming it could use a new thermostat, but would the thermostat cause the temps to go that high while just idling, or do I need to look at something else as the cause of excess heat. . I didn't think these engines would get that hot just idling especially in relatively cool temps without the AC running.

 

[IACumminsTBD]

Yep my 03 did the same thing and it jumped up to around 220-230s. Not fun. Thermostat change and sits perfect at 185 again. It was kind of a scary ordeal cause i really didn't want my temp to get that high. It actually happend like 3 times to me. But yep the thermostat should change that.