100-110C looks normall to me when driving in stop and go trafic or when under heavy load, but there are some things you could check:
- Aux fans working in the wrong direction? They need blow air to the radiator and start on high speed at about 105C.
- I thermostat in goog condition?
- Expansion tank pressure cap with good seal?
- Have you drained the coolant recently? There could be air traped in the system.
- Coolant leaks?
- Fan clutch, but you said it's good.
- Radiator might be bad in the inside (cloged).
If you haven't yet, I would start by installing a new pressure cap and thermostat. Those are cheap and are very important.
If you have no mayo inside the coolant tank, you head and head gasket are ok.
I hope this helps.