So as most owners of the 03-ish civic know, I've had over heating issues since around 150k miles. I'm now at 260k miles and had coolant bubbling out the radiator after a long drive and hill last week. I'm assuming head gasket but the block leak test I did found no exhaust gases in the coolant. A compression test yielded 150 psi, 130, 125 and 140. My coolant is circulating but the fans only come on when the ac is on. Water pump is only 6 years old, radiator is around the same age. I've bled the system of air a few times. I'm pretty sure there is a head gasket issue but I don't have any milky oil, white smoke, etc. I just put a new thermostat and fan temp switch in but as I was trouble shooting I realized the radiator fan never comes on. Ever. Only when the AC is on then both fans worked. I just put a new fan switch temp in (one on thermostat housing). I can sit parked with ac on and zero issues. Turn the ac off and the coolant gets extremely hot to the point of steaming out. Top hose is around 130 and bottom is 100. When the ac is on the temp difference drops, ac off, the top hose skyrockets. Tomorrow I'm doing a coolant system pressure test to keep on the head gasket route but what is causing the radiator fan to not come on at all?

 

I am having similar issues and i was wondering are you also having heat issues inside the cabin?

 

The heat works but generally only after the car has been running for a while. It will alternate blowing hot air and then cold air.

 

Sounds all too familiar , My 04 had over heating problems . After having problems with cheap thermostats I got one from the dealer , your temp. sensor from auto zoo may be unreliable also . I got a crank sensor from nipa and it was a P.O.S. so you have to be careful not to make assumptions . Why your fans don't come on I don't know but I too did the block test and it came up negative , my compression test results sound similar to yours also , eventually the head gasket gave out , the thing still ran though . After pulling the head and bringing it to a shop the said it was warped by .006 thing is they could plane the block surface but the cam galley journals would still be warped so the head was junk . If you get a re-man head they say the rings are used to the worn valves and the increase in compression blows them out . I would get the fans to come on when it gets warm and hope for the best but expect the gasket to go eventually .

 

Yea I'm not hopeful on it. But the car gave me 260k miles so it's been paid for many times. I know it's a head gasket issue. I'm going to buy an old 88 Jeep Wagoneer that has a solid engine so I can keep working on a car but the civic is toast. I don't feel like spending 1600 on a head gasket repair and I've heard it often causes other issues. I might try a sealant like steel seal and squeeze some extra life out of it but this girl is just circling the drain.