[Amen]

I replaced the coolant temperature sensor and the rough starts and idles went away!
BUT THE OVERHEATING IS BACK!!!

So far I've flushed the cooling system several times, replaced the thermostat, replaced the fuel filter, and replaced the coolant temp sensor. I also took off the coolant reservoir and the upper and lower hoses and cleaned them all thoroughly.
When the car starts to overheat, smoke will come out of the coolant reservoir cap first and then the coolant will later boil out of that cap.
I'm thinking radiator or water pump but not sure how to tell which one it is. I want to be sure.