honda civic defroster help

my wife has an 03' honda civic for her commuter car. every morning i go out and start it and let it warm up for about 15 minutes. the engine will be completely warm but wont defrost the windshield until the car is moving. any ideas whats going on?

 

Is the heat coming out of the vents warm? Keep in mind the heater gets its heat from the coolant of the engine running across the heater core. You usually won't get to full operating/optimum temp until you drive it a little and put then engine under some load to create heat.

 

the air coming out is somewhere between warm and cold, it never had a problem before this year and always defrosted just fine

 

A cheap test would be to replace the thermostat. you might not be noticing any issues (other than the defrosting) because of the outide temp. But if the thermostat isn't opening when it should it could be preventing the hot coolant from getting to the heater core.

 

Agreed, A New thermostat should cost you less than $20 and is easy to replace.

 

good deal ill try that first

 

a new thermo sounds like its needed. when i did my integra.. it was like 7 bucks but a pain to get to. is the civic a SOHC or DOHC? if its a B series engine. its going to be tough to get to lol. good luck.

 

whats a honda civic??

 

Before you go throwing thermostats into the vehicle....

-Check the coolant level in the radiator. If it's low, add some fluid.

Also a good time to determine if you have a possible coolant leak.

-Investigate your radiator cap a little more closely. Have it tested to see if it's holding pressure.

 

This too...I once had a cooling issue in my old accord. I turned out to be a bad radiator cap which was also causing air to get in the system. Replaced the cap and bled the system and it was good again.