I have a 2002 Honda Civic Ex with the D17A2 motor and have been having constant problems with coolant being pushed out of the radiator overflow reservoir. I took it to a Honda certified mechanic who said that it was the head gasket. I then took it to another mechanic that the family uses who said that it wasn't the head gasket and replaced the radiator cap. That didn't fix it. One of his other mechanics said that he heard a rattle in the water pump, (which had only 11,000 miles on it since it had been changed at the timing belt service,) and told me that the water pump needed to be replaced - which he did. That didn't fix it either. After taking a drive at highway speeds and higher RPM's it's pushing the coolant out again and the radiator is holding it's pressure even when the engine is cold. It also pushes alot of coolant out when the engine is started.

There is no smoke coming out the exhaust, and the oil seems to be clean. (Had the oil changed when the water pump was replaced and they didn't say anything about it.) The two non-Honda mechanics both have told me that the head gasket is "okay" but I'm not buying it. I know that a head gasket leak can be small enough that coolant won't get through but the cylinder pressure will leading to over-pressurization of the cooling system. I asked them if they had done a compression test and they said the head was "sound." Once again I'm not buying it. I'm convinced it's the head gasket. Am I right to think that?

 

Wow, that's a lot of work done without anyone doing a simple hydrocarbon test in the coolant. Or even simpler, with engine cold, and radiator full to the neck, remove cap, start car, look for little bubbles. If you see little bubbles, that means the HG is letting the cylinder pressurize the coolant system (above that what the radiator cap allows) therefore it pushes coolant out.

You say the radiator holds pressure, but for how long did you run the test. If it's a small leak, it could take awhile to see the loss.

You can easily have clean oil yet have a blown HG.

A small HG leak cant usually be seen with a compression test. Its only a small amount of air/fuel mixture that is lost on each compression stroke, but you have to remember that the piston is moving up and down many many times per second so the overall contribution to the cooling system becomes a lot. And the reason you look for little bubbles (mentioned above) is because it's like a pin sized leak that's shooting air into the coolant.

 

I actually did take the cap off the radiator yesterday and started the engine cold. It spit a bunch of coolant out and then the level dropped but I do remember seeing little bubbles in the coolant. I have a bad feeling I have had alot of unnecessary work done and should have had the head gasket done to begin with. I have never heard a Hydrocarbon test mentioned by the non-honda mechanics either. Thank you for your thoughts.

 

It a bad head gasket..