heater problems?

Question

i have a 75 chevy and the heater is not working right, it blows cold air and the therm is new, i think that the coolant is not flowing to the heater core because the hoses are cold after i run it, whats wrong with??

Answer 1

It could be that the heater core is pluged, or the heater controll valve is not opining and alowing water to get into the heater .
Check this
Feel both hoses, is one hot and one cold?
That means water is going in but not out.
Back flush the heater core.
If both hoses are hot then the heater controll door( the door that alows heat to come into the car is bad.

Answer 2

What does the temperature gauge say? If temperature normal, then your thermostat is OK.
If temperature below normal, then you have a defective thermostat. Is it after-market? I had a bad experience with Toyota pickup, where I changed the thermostat twice (both after-market). Finally went to Toyota dealer, and no problem after. If water pump was so weak that it would not circulate the coolant through the heater core, then, chances are the engine would overheat. Next step, check to make sure that the valve, on the heater hose, if there is one, is open. If all checks out, then flush heater core.

Answer 3

on the pass. side under the hood where 2 water hoses enter heater core. there should be a heater control valve which is operated by vacuum. replace it if its bad or by-pass it with a brass coupling.

Answer 4

i own a repair shop,and the fins on the water pump that help push the water when the pump turns may be getting worn out on it and this wont make the coolant circulate real good ,and that will cause it not to heat up real good the pump doesn't have to leak to be bad,it can be worn out and still not leak a drop of coolant on it,and you may need to flush it all out the heater core may be stopped up a little on it,good luck with it,i hope this help,s.

Answer 5

heater core plugged

Answer 6

heater core its plugged up