"Normal" Coolant Temperature

The heater doesnt open the tstat, but if your tstat doesnt open you have no heat. And if your tstat doesnt open your engine overheats. Running straight antifreeze is expensive and far from ideal but it alone wont make you overheat either.

 

Solved. SPLOOSH! (If you ever watched the adult themed cartoon Archer you'll get that reference). Drove the Taco to work today and it stayed at about 188 solid. Never a needle fluctuation, and the ScanGauge stayed true as well.

By chance my jiggle valve was at 12 o'clock. I had air in the system as when I buttoned it up the first time the coolant was at the cap, and when I went to do these checks it was about half a gal low. I did not have a leak. So I worked the air out and lost that volume. That probably had a little to do with it, certainly the lower coolant level and slightly higher temp.

I think the big deal was the 100% coolant with no water in it. Less efficient. I drained the radiator and filled with the 50/50 as well as filled the overflow to the appropriate level. I ran that thing for something like 20 minutes and could never get it over 188 with the heater on. Finally shut it off and peaked at 193 for a moment, then ran around 191. Put the heater back on and dropped it to the 186/188 range again. But I left the cap off long enough to help purge air.

Any way, the commute today stayed at the 188 range, even in the much hotter afternoon. Yeah!

Lesson learned: give it enough time to purge air, and don't use concentrate/100% coolant. I just didn't pay attention to the jug I bought!

 

OP, thanks for the update and glad that you got it sorted out.

 

Awesome! Glad you found the prob.