Les, why not tell us your theory and what results would prove it out?

 

That is where my 2000 blazer has always ran with temp gauge. I started looking into why a while ago . And found everything normal .

Scanner shows it being 182 deg but when I put an accurate thermometer in water flow stream from engine in the radiator and it showed water temp to be 192deg. this was an accurate temperature so I know it is not running cold or hot when gauge is where it is . My t-stat is a standard 195deg. So from scanner showing 182 and 195 stat It’s only about a 7% difference so within tolerances I would expect . IR thermometers typically are plus or minus a few percent and are most accurate in flat black non shiny surfaces.
Since the temp sensor is a thermistor ( thermal resister) its accuracy is not great or linear , the resistance change varies with varying temperatures . Also the dash gauge is not linear or calibrated with the hash marks on it . The only possible calibrated temperatures are the 3 temps listed 100; 210;260 . Each hash mark on gauge does not represent a specific number of degrees , as evidenced by the left half of gauge covers 110 degrees of temp while the right half covers only 50 degrees . Which is typical of a non linear gauge . Its main function is to be around center for normal , which it kind of is, but primarily it needs to notify when overheating . So its accuracy is built into the higher temp range.
The thermostat starts to open at the rated temp so 195 t stat begins to open at 195ish and won’t fully open until gets hotter to regulate water flow .
Given the inaccuracy of the sensors and gauge,
I would guess that your thermostat , fan water pump and radiator are all working as they should be . Its not that gauge is not accurate, it just is not calibrated to read any specific running temp , but instead it’s made to indicate a cold , normal , or overheated engine .

 

I just wanted to know if the engine was being cooled extra by the heater core.

 

I figured it was something like that but what would you conclude from the results?