What’s Going On With My Cooling System? Do I Have a Blown Headgasket?

[college man]

If your not seeing coolant in the oil or oil in the coolant its just air. Which on the asian cars are hard to bleed. I would have
Recommended replacing the thermostat with a new cap when the coolant was done. Button it up and see if it overheats?
I believe its just air. Keep an eye on the overflow.