I have been having problems with my 95 trans am lt1 it keeps running extreamly hot i never allow it to get in the red though the heater blows cold air i have replaced everthing the car store told me could be wrong then i was looking up on line that the water pump could be bad went to car part store had them check they told me as long as it is not leaking and the pulley is turning it is good is that true and could it be anything else???? HELP