@Mark_Cool Did you ever have any luck with the sensors if they were bad or not?

 

I haven’t swapped out the lower one in the block. I’d lay odds that that sensor is faulty and giving a bad reading in the dash gauge.

The meat thermometer is 60-80 degrees below the gauge reading. I’ve been driving the truck around and it’s not overheating, despite what the gauge says.

I just haven’t felt like swapping it out yet.

 

Coolant temp sensors are a common failure in lots of GM vehicles. Fans always on. gauge readings off or A/C not working due to them is common.,