03 ex overheating issues

ok im trying to find this out for a friend, he has a 03 civic ex with around 100K on it, it has started to overheat at random, it happens usually after he passes someone or turns on the a/c, he has taken it to 2 different dealerships, they cant find anything wrong with it they ran dye through the cooling system, fans work properly and everything, cant find a clog or leak. when it happens the temp gauge goes up and it spews coolant from the overflow onto the engine. they cant figure it out, has anyone else had this issue?

I have the same problem. If you find out what wrong , please let me know.

I would look for a partially plugged radiator.

I just started having this problem. In fact, it's why I joined this forum...

I have 2003 Civic Ex with 110k on the clock. I too have been having random overheating issues. My wrench has replaced the thermostat, but that wasn't it. Currently he's doing the timing belt and water pump (it's time anyway) but the water pump impeller seems fine. He's going to drive home for the next couple of days and see if he can get it to happen to him. Right now he's really stumped.

I did notice during the last episode that the heater stopped blowing hot air when it happened. So it seems that cicuolation is not happening. Any thoughs would be appreciated.

Chris

I would disconnect both heater hoses and flush the heater core. Check that both the top and bottom hoses are hot and appx. the same temperature. When it reaches operating temperature.
Then make sure the fans come on.