Odd temperature activities

jos51700 said
If it was me, i would pull the thermostat sand change nothing else, and see what happens.

Then, when you replace it, find one that's not made in China. See if the issue persists

RustyRatRod said
Gosh, good luck with THAT!

I THINK Stewart Components thermostats are made here, I'm not sure.

MotoRad is made in Israel, Edelbrock is USA. Stant is international and luck of the draw what you end up with. MotoRad makes thermostats for most of the other brands, which is why you end up with Israel for a lot of the house brands and OE labels.