well either your heater core is bad or your outer window door seal is leaking . i had the same problem on my Monte Carlo and i had to remove 1 of the studs that hold on the weather striping on the lower part of the door so it could drain .
Water pump removal chevy monte carlo 3.8
Ebay..!!
whats the eigine size
In a 1997 Monte Carlo Z34 you will require 1 and 3/8 gallons of antifreeze. ?æThis is to be mixed with an equal measurement of distilled water.
Very likely
Blown head gasket.
bad door seals
http://www.youtube.com/watch?v=n0u5uOC_YIo This is good
Your cabin filter seal is missing or out of place.
Follow the top radiator hose down to the water outlet on the engine. It is in the water outlet.
Not sure what you mean by "hot water valve". More info please.
You've got yourself a bad heater core, I am sad to say. Or the door sills are full of leaves/debris.