For the last 3 winters, I have had problems with my heat blowing cool air in the winter and never warming up. Every winter, I take it somewhere, they try something, it works for a little while, and then it stops working again. Eventually, the weather warms up, and it's not a problem anymore. Last summer, I started having problems with the air conditioning too. I had them look at it at my 100,000 check, and they recharged it. It was fine for a while until I went on a trip, and noticed the air getting hot again. I looked down, and my car was overheating. Long story short, they bled the system, found a loose clamp and replaced the relays (sorry, I don't know much about cars). I didn't have any further problems until this winter, again. The heat was blowing cold air, and my car overheated again. This has happened several times now, and most recently, after I thought it was fixed, I noticed a correlation (this was not the case in the past). I was driving home from a 180 mile round trip, when just as I was a few miles from home, the heat started blowing cold air (all after I thought it was fixed and hadn't had any problems). I looked down at the thermostat, and the temp was rising, and the car overheated. Before last summer, I had never had any problems with the car overheating when the heat wasn't working. Now, it seems like the two things might be related. Does anyone have any idea what might be going on? I know that the thermostat has been replaced, the relays have been replaced, it's not a blown head gasket, and the system has been bled several times. I'm so tired of this situation. I'm ready to just get rid of the car!

 

Welcome in,if you recently had the coolant changed it may be air in the system or ,once again a bad thermostat,they go bad, and I have bought a new one in the past and it lasted maybe two days, you may want to have the pressure checked and maybe replace the thermostat once again,and replace the rad cap also.

 

i post this video to much but i wouldn't rule out a blown head gaskit since the 01-05 civics are notorious for that.

 

Or your heater core is partially blocked

 

Would the heater core being blocked cause the car to overheat?

 

Most likely not
Loss of coolant will cause overheat
Blocked heater core will cause no heat in car
If you have the a/c on cold and it starts to blow warm air when the car is overheating thats normal
I say its either blown head gasket or a coolant leak
Have the cooling system pressure tested
If there are any external leaks you will see it

 

I finally brought my car to the Honda dealer to have them look at it. The guy told me that I likely have a bad/blown head gasket and may need a new motor. Does this sound legit? I went to the last place I took it to talk to them about what Honda said. The lady there said that if it was bad enough that coolant was mixed with the oil, that I might need a new motor, but they would have noticed that when they changed my oil in February (I was having the same problem then).

 

a blown head gaskit doesn't necessarily mean you need a new engine only if it overheated bad enough to warp the head but even then you can have the head plaind down at a machine shop then reinstalld. i would get a second opinion alot of mechanics are shady and like to take advantage especially dealers.