I have a 2015 5.0 Canadian truck. Bought it early summer and always had the a/c on. Coolant temps always stayed around 198-205 F. Didn’t need the a/c the past two days so I had it off and the coolant temps fluctuated between 210-223 the whole time.

Same with the trans temp. Used to stay around 200 degrees, but the past two days stays around 210. The fans come on and vents open at 220 degrees but never gets below 210 with the a/c off. I turn the a/c on and it comes back down to 200 degrees. Is this normal?

 

Probably. The cooling fans are automatically engaged when AC is on so that the condenser can do its job. If the A/C isn't on, then the temps are allowed to wander within their permitted range.

 

You did not say when the temps go up.I would just make sure your radiator and condenser fins are not bent or plugged with debris and your fan is coming on at the right temp. when your a/c is off. I would think the fans should be coming on at 223.

 

Guess it’s just normal then. Thanks.