My car is a zx3. It overheats at stop lights and stop signs. It drinks A LOT of water. My fans work, thermostat is new, coolant tank is new. It's fine when I'm moving but overheats when I'm idle. No leaks.
My car has 186000 miles.
My car has an automatic transmission.
If the vehicle is loosing coolant without any external leaks then you may have a blown head gasket. I’d suggest having the system pressure tested to see if an external or internal leak is found or if there is another problem like a clogged radiator.
If you decide to get this fixed, consider YourMechanic, as a certified technician can diagnose your overheating issue firsthand and suggest an accurate repair from there. Good luck.