240;104362 wrote
Which is the cold side.
So your engine is getting up to temp, continuing to get hot, then after the coolant and radiator are heatsoaked beyond the thermoswitch, the probe finally start reading.
This isnt all bad. So as long as it doesn't spike before it can catch up.
What I found when I was running the probe in the lower hose, the fan would cycle way too frequently. Although was only short periods.
Where as the top hose (hot) would cycle for longer and less frequently. Which dropped the overall temp further and for longer periods of time.
Note this is also the position recommended by most cooling systems.
