2021 1500 5.7 coolant temp went nuts

[SD Rebel]

Yes it goes beyond 230F up to like 256 or 260 when I really punch it enough for the truck to ding and initiate the red screen stating it’s overheating. I really have to throttle down to get it to come back down to the above degrees 228 - 230

Okay, that's not good, you definitely need to take it in.

While oil temp can actually hit 280F before you get a warning while under extreme towing, your coolant temps should never go beyond 255F in those conditions, I think you get the warning at 255F.

But you're not even doing that, you're just driving around, you definitely should not be going beyond 230F without something being towed.

 

[pluto665]

I bought a used 2021 1500 and it started doing this. After taking it to the dealer and them saying there was no problem I was going to try a thermostat. While changing it I noticed the crazy water pump belt was almost 1/2 the width it should be and was loose. Under acceleration it was slipping- new belt cured the problem. First time I had come across the single use belt situation.