overheating problems on 2002 Chevrolet Camaro

car overheated appox 2wks ago;pulled the thermastat out, still overheats;
pulled the radiator had it cleaned boiled and rodded out; still overheats.(no water in rad)no water in oil, where is the water going? no leaks from the water pump, usually takes 2-3 days to start overheating after filling it back up with water & coolent, fans are good; could the impeller be froze up in the water pump,no noise coming from it either,any way to check the water pump with out pulling it off,if not how's the best way to pull the pump off on this model??

1 answer
take off radiator cap (when cold) once it heats up enough to open thermastat you should be able rev engine and see water flowing inside radiator if theres no flow what so ever its probley water pump