2003 Honda Civic no Heat
- Thread starter hitenk108
- Start date
New Vega
HondArmy
Sounds like air lock in the heater core.
A vehicle heater that fails to produce heat after a sufficient vehicle warm-up period is often a sign of heater core failure. A heater core is designed to produce heat as soon as circulating engine coolant becomes sufficiently heated by engine heat. A failed heater core loses its ability to become heated.
I'd start with being sure that the coolant level is proper and if any coolant leaks exist , then test the coolant quality and mixture to see to see if it's good for a good -40c and mixed about 50/50 , then test or and change the thermostat be sure it's one rated for the winter season or a good all season thermostat can be used but usually you gain more heat with the winter thermostat but always check factory recommended specs before hand.
A real good advantage or first step is being sure that the coolant is of good quality and if you know it's not been changed or could use changing it's best to start with checking the whole coolant system from the rad to the engine etc for any possible corrosion or leaks etc.Always change the thermostat when you change the coolant or a rad but be sure any old or needed replaced hoses and hose clamps are also changed.
Once you know the coolant and mixture etc are okay then be sure that the heater-core hoses are okay and with the engine idling awhile and warmed up with no heat on at least one of those two hoses should be getting hot and with the blower motor and heat on full both the two hoses should get hot. When only one heater-core gets hot that could mean an air bubble or air clog or dirt exists etc within the heater-core itself and it could just require a coolant system bleeding or the heater-core to be flushed or the heater-core is faulty etc.
If you squeeze the rad hose when the engine is cold started the hose should start over a bit of time to push back on your hand and it should get hot.So if no pressure check the thermostat or replace it.
Hope that helps and best of luck.By the way I'am sure it's not really a major problem just double check all the coolant system and I'am sure you will find it.
Besta luck!
A vehicle heater that fails to produce heat after a sufficient vehicle warm-up period is often a sign of heater core failure. A heater core is designed to produce heat as soon as circulating engine coolant becomes sufficiently heated by engine heat. A failed heater core loses its ability to become heated.
I'd start with being sure that the coolant level is proper and if any coolant leaks exist , then test the coolant quality and mixture to see to see if it's good for a good -40c and mixed about 50/50 , then test or and change the thermostat be sure it's one rated for the winter season or a good all season thermostat can be used but usually you gain more heat with the winter thermostat but always check factory recommended specs before hand.
A real good advantage or first step is being sure that the coolant is of good quality and if you know it's not been changed or could use changing it's best to start with checking the whole coolant system from the rad to the engine etc for any possible corrosion or leaks etc.Always change the thermostat when you change the coolant or a rad but be sure any old or needed replaced hoses and hose clamps are also changed.
Once you know the coolant and mixture etc are okay then be sure that the heater-core hoses are okay and with the engine idling awhile and warmed up with no heat on at least one of those two hoses should be getting hot and with the blower motor and heat on full both the two hoses should get hot. When only one heater-core gets hot that could mean an air bubble or air clog or dirt exists etc within the heater-core itself and it could just require a coolant system bleeding or the heater-core to be flushed or the heater-core is faulty etc.
If you squeeze the rad hose when the engine is cold started the hose should start over a bit of time to push back on your hand and it should get hot.So if no pressure check the thermostat or replace it.
Hope that helps and best of luck.By the way I'am sure it's not really a major problem just double check all the coolant system and I'am sure you will find it.
Besta luck!