My car has stock programming and I have a 180 thermo. When I'm moving, there's plenty of airflow and the car always runs fairly cool. However if I just let the car idle, the temps will rise up to ~230, the high fans will come on and the car will cool fairly quickly to approximately ~210, then that cycle will slowly repeat until I start moving again.

I know stock programming has the high fans turning on in that range, but my question is if it is normal for the temps to just fluctuate between ~230 and ~210 while the car is idling.

 

Normal.

Rich

 

Exactly. Any car with electric fans does this. Think about it. When you stop moving there is no longer any air flow. No air flow, engine heats up. The fans come on, there is air flow again. Engine cools down.