I have an 04 accord ex coupe and when the car is sitting at a stand still the heat blows cool air but while driving it blows hot air. Can someone please help me fix this problem?

 

Either you don't have enough coolant in your car or your thermostat is bad. Change with Honda parts (thermostat $20 and coolant $20). This would be a good time to do a drain and fill with Honda coolant.

 

1st off let's say that stir fry boy has a good answer for you to do 1st..and let's sak You...what have you done to correct or researched your problem already.?

WheelBrokerAng

 

All I have been able to do so far is search this forum for help. I have been working the night shift and my wife called me last night and told me what it was doing so I was trying to just see where would be the best place to start looking. Thanks for the help so far. Will keep you updated.

 

I have drained and flushed the radiator and am flushing again and the heat is kicking out great now. Thanks for the help.

 

Hondas (as a general rule) do NOT like to have air pockets in the cooling system. Your 2004 doesn't have a bleed-valve like earlier ones. But still, turn the heat all the way up and run awhile to allow air to collect at the radiator cap. Then open & top it off when it's cool enough to do that safely.

Your thermostat is very easy to replace, if needed. Get one from a Honda dealer cause they seem more reliable and they aren't stupid expensive. The lower radiator hose comes from the bottom of the radiator & crosses diagonally to the thermostat housing. There's a metal spring-clip that you squeeze & pop the T-stat housing open. (All the guys with F-series engines are green with envy)