I have 96 civic and had quite similar issues. My car would not overheat on the highway or interstate but it would when around town. Usually when stopped at a light, but if I continued moving it would cool back down. I replaced the thermostat twice thinking that was the problem but it did not fix it. Also checked the water pump and it was in perfect working condition and all fans were working properly.

It actually turned out to be a warped head. It had a very slight warp and coolant was leaking into the oil. It was odd because it wasn't enough to show any white exhaust to give me any sign that was the problem. One thing I did notice is that I was always out of Antifreeze, but there were NO leaks anywhere. I also had black residue in the coolant overflow tank. Turns out that residue was oil, from where the oil/antifreeze mixed where the head was warped. Me and my brother ended up fixing it, luckily the warp was small enough that a local shop was able to grind the head down enough to make it level again. We put it all back together and put a new head gasket on and the overheating is gone. The warp of the head was so minute that it only caused issues when it was warm, i assume providing a small gap for antifreeze and oil to mix. Causing low antifreeze levels=overheating. It also caused the black/oil residue in my the coolant overflow tank.

BTW the warp of the head was so small, i forgot how much it was off. But we're talking fractions of an inch, that's all it took to cause me lots of issues.

My car also only provided heat when moving, and last year on 2 really cold days I didn't get heat at all. I'm assuming this was from the lack of antifreeze and/or air bubbles in the system. As it gets colder I will know for sure if fixing the warped head also fixes my heating problem, which I think it will.

 

I did all the cheap easy things ( i.e., changed thermostat, radiator cap, purged the air from the system) without luck. I am going to change the head gasket next. I'm ording parts tomorrow and will tackle it before Thanksgiving. I will post with results.

 

It might be a good idea to find a place that can check to see if you head is warped before reassembling it and putting the new head gasket on. It only cost me $50 to take the head into a shop and have them mill it down to get rid of the warp.

 

Replaced head gasket and all is well. It is worth the additional $35-50 to have the head milled and then for another $50 can get all the valve stem seals replaced. I did my own due to garage shutting down from Thanksgiving to Monday. It wasn't hard if you have a spring compressor.
BTW, this is the most recent model vehicle (2004) I have had to work on extensively. It appears that Honda is designing throw away vehicles since this one is not designed to be maintained very easily. The intake manifold threw me for loop with the three bolts underneath and removal of their brackets required. Timing belt removal was hard with the fender right there. But it all worked out.

 

have you fixed the problem?....let me know

 

Have you fixed your problem?...have the same issues. Let me know what you did.

Mario, nova scotia, canada.

 

have you fixed your problem? have the same issues.

Mario