whatcausesmyengine keeps heating upwhilerunning esp uphill,itjustdoes itrecently

What is your question?

just put in OEM coolant &thermostat just before passing smog, I ended up taking out the T'stat completely but still running hot up to the red mark, the OBD tester is all OK result. no coolant leaks or wter pump leakand it doesnt eats or evaporate coolant, i am a moderate DIY selfer. cant think of anything else but maybe my water pump blade is gone, i have 237K miles on it bought with 195K 2 yrs ago. thanks