I have a 2000 SI the heater has always worked GREAT.
Now this winter all I get is cold air.

Engine temp is normal,cable is connected to water valve and working.

Should I try a radiater flush product?


Peace,DEDO

 

check coolant level, flush if you havent in awhile, check tstat, make sure blend door is working. if above fails, you probably have a crappy heater core.

 

Check coolant and thermostat.Pretty much what he said ^

 

Unless you have visually seen movement of the water valve, check the pushrod under the dash just to right of the radio. Sometimes a passenger's foot will knock the clip loose and the rod will become disconnected. Its super easy to hook it back up. If it's disconnected your heater water valve will not function.

 

Does the engine warm up normally/quickly when cold?

Are you say that you have verified that the heater hose valve on the firewall is fully opened?

Have you topped off the radiator and bled the cooling system?