I have a 528e which still overheats after doing the following:

Replaced head gasket and checked flatness of head and block.
Flushing radiator and block.
Removing thermostat, testing, then replacing with new.
Bypassing fan thermostatic switches to force fan to run at high speed
full time.
New water pump.
Bled all air out of cooling system.
No leaks.

Any suggestions?

Many thanks to the group.