Spotted Silver 33 GTS-t with a minor overheating issue on Athlon last night around 9pm
Stopped to lend a hand but left just offering advice
Flush properly
Make certain thermostat is in correct way (replaced that day)
Use Coolant
Do with heater on full
- is water pump pumping ?
Bleed air off before driving, if possible
Check water level after driving for a while
Oh - it was a relatively new Rad as well.