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Help me ID a mystery hose! 2002 Subaru Impreza leaking coolant

2002 Subaru Impreza leaking coolant; found the source was an OPEN hose leading INTO the engine compartment from the dashboard area (passenger side)! Anybody know what the hose is or should connect to?

The hose is just … open! I can’t find anything else it should be connected to. Other videos and diagrams I’ve seen show a hose connecting to the top passenger side of the radiator, so I thought maybe it should connect there … but mine has a bolt cap on it, so maybe that’s just for turbo. In the first pic, I also circled the bracket that holds it in place (removed for greater visibility in the pic). Thanks!

That’s the condensate drain hose for the AC.


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Maybe a drain from the bottom of the HVAC housing (if it’s draining coolant from a leaking heater core) or from the AC (if water.)

Makes sense, thanks. Sometimes it leaks water, sometimes coolant.

If it leaks coolant, and that’s the only place I can find coolant exiting the vehicle, does that mean the heating core is what needs to be replaced? Or could there be another (less pricey) fix? Don’t suppose Bar Stopleak would work on something like that?

If it’s not leaking, you have a problem. You can tell that the condenser cavity isn’t draining adequately if you hear water sloshing around below the dashboard.

If that hose leaks coolant, it can only come from the heater core.



You guys are fast! Most helpful folks on the web : ). Thanks. Well, I have the rest of the week free and a desire to become more car self-sufficient … do you think a relative newb can replace one of these?

That can be difficult to say, unless somebody here knows how to do it. I’ve seen cars where it would take ten minutes to change it and I’ve seen a few where only a stick of dynamite would create acces to the heatercore.
Try Youtube to see if there is a video pertaining to Your car.

Yeahhhhh looks like a nightmare. I think I’ll try a flush & leakstop to see if that will help. Thanks.

Are you having to add coolant? How much?

It really depends! For the past week it seemed like the reservoir completely emptied out every two days (and I was seeing medium-size puddles under the heater core drain). I would sometimes need to stop and refill while driving. But for the past two days the reservoir has been holding steady.

No other leaks that I can find, and none of the head gasket symptoms I’ve heard about (no smoky exhaust, no watery oil, etc.).

That’s a big leak, get it fixed asap before you fry you engine.

Determine the size of the heater hoses.

Go to a parts store and purchase a hose that looks like this.

Also purchase two barbed hose couplers,

And four worm drive hose clamps.

Remove the two heater hoses at the firewall and connect them together using these components.

At least for now you’ve stopped the leak.



Thanks, that’s awesome! I really appreciate the help. If you don’t mind explaining, how does this fix it? Does it just take the heating core out of the loop?

Unfortunately, I can’t even figure out where the heater hoses are exiting the firewall … (yep, I’m pretty clueless about cars, but I’m trying to learn!).

That’s the idea,


This should look like your car, except you won’t have the clutch master cylinder (the silver object with the yellow cap) if you have an automatic. The heater hoses are just to the left of the master cylinder:

You folks are amazing. Are you getting paid!?

Sure! 60 minutes per hour!