Weird temp gauge issue, only reads with RPM

[Probesport]

I haven't had a chance to look into it yet, just wondering if anyone else has seen this.

My temp gauge all of a sudden is acting a fool. At idle/low RPM it sits at the bottom (cold) and only goes back into range with throttle. It gets to normal as it should and stays there until RPM drops down again. No overheating, fans working just fine, no other issues.

I'm assuming the gauge is going bad but I'll swap out the sensor tonight as well.

Is this how the gauge itself dies?

[NickR]

Weird. Just a wild guess, but check the coolant level. At higher rpm the water pump will be working faster, and maybe getting coolant to the sensor???