Kia Troubleshooting Questions? Ask a Mechanic
Hello and welcome to just answer, my name is ***** ***** master tech here to help. I cannot see or hear your vehicle so I rely on your patience and input to my questions to help you better. I read your notes and ready to help.
these are things that can cause over heating.  thermostat,  bad rad cap, not holding proper pressure,  Radiator -loose or missing cooling fins , check the bottom fins,  cooling fan not coming on or if clutch type not turning properly,  head gasket leaking compression.
So the first thing to do is a visual of the radiator cooling fins, and if it is loosing coolant. If those check ok then replace the rad cap and thermostat. If still overheats then do a block test for leaking head gasket.
hear is what to look for if suspecting head gasket and the tool to check for that. Bubbles or foam in the coolant , make sure is full to the neck.
Hope this gives you a place to start to solve this issue and if you need further help let me know or please take the time to rate my service . Thank you for using JUST ANSWER.