Engine overheating

Driving a 2003 Acura TL Type-S, i’ve been having overheating problems for the past 6 months to a year. The radiator, water pump, thermostat, and radiator cap have all been replaced and im still having problems. I had to pull over to a kwik lube today because it was overheating so bad, the mechanic there said that it could be the fan not working properly, but that can’t be the case because the fans work fine. The car usually overheats when idle and returns back to normal when im driving, i changed the thermostat yesterday hoping it would fix my problems but now it just overheats after 30 minutes of driving whether im driving or idle. No leaks in the hoses, i purged the coolant and bled it out properly after the thermostat was replaced, i really don’t know what else could be the problem except head gasket issues. And i really hope that isn’t the case..any ideas??