Coolant temp running higher than normal.

2023 Cummins
Radiator 2? years old full clean and free of debris. Was a dealer installed unit.

Normal operating temperature is 181-183 unless I’m climbing hills heavy. Been pulling mostly light loads lately and noticed the temperature increases starting two weeks ago. Been running in the SE lately where it’s been hot in the 90’s. Even so I’d never seen more than 185 ish in these temps.

Been using the manual fan switch a lot lately and it doesn’t seem to bring the temp down as quickly as before.

Not wanting to deal with dealerships and their diagnostic fees quite yet.

Thinking to throw a new thermostat at it and new temperature sensor. I’ve done many thermostats on 4 cars I’ve owned but never a truck engine. I’m guessing it’s an easy DIY project?

Personally I’ve never had a thermostat fail so I’m skeptical of that being the culprit.

Can anyone tell me if I possibly got something else sinister going on?

Worst case scenario I’ll drop it off at the dealership at the end of the month. Taking first two weeks of July off.

 

I should add..
Higher than normal, meaning that it’ll get over 200 and kick the fan on at 208 if I don’t watch it.

I run a lot of mountains heavy so out of habit I’m constantly watching the temp gauge. Always turning the fan on manually once it starts heading towards 200.

 

Thanks.
Can’t believe that they don’t put manual switches in every truck.

I always kick mine on for a couple minutes before I shut down the engine.. Just one of my many quirks, lol.

 

That makes sense and I’ll take a closer look tomorrow when the sun rises.

Could have something to do with the swarm of honeybees I went through a few weeks back. The swarm was absolutely insane and completely covered my trunk in a fraction of a second..sound of them hitting all at once was incredible!

Haven’t driven in much rain since or wash my truck regularly like I used to either.