Hello.
I have 00 civic EX 2dr which has 137k on it. While I changed oil last night, the green fluid was found underneath back side of engine where the catalytic converter is right next to. It is hard to describe where it is from. I couldn't find the source because there are too complicate to find. Here are some pictures. Please help me!!!





Thanks.

 

what does the leak smell like? antifreeze?

 

Check the heater control valve located on the firewall towards the passenger side of the vehicle.

Also check the heater hoses coming off of the control valve as well, as they can leak as well.

Here's an exploded diagram of the control valve and the hoses coming off of it - note the front of vehicle indicator in the top right corner of the diagram:



#1 is the valve itself (#10 is one too, but there is only one per car - must be for a different model)

#2 is the hose that goes from the water valve to the cylinder head and attached to it just under the distributor - this hose is a common leak too, especially of your distributor is leaking oil onto this hose

 

What is the distributor? I can not understand that diagram. Is this top view of the engine?

Thanks.

 

the valve is on the firewall right above the converter.