Unclog a/c drain and remove musty smell easily


SkyActiv Member
State of Jefferson
2017 CX-5 GT AWD+
Thanks, tomcat. I've had the smell in every car I've owned. Your step by step is invaluable. I'll be ready when it gets bad.
I think I may have this issue on my 2003 Protege5. I am struggling to remove this trim to get access to the drain. I loosened the screw, it is very loose on the left side but seems stuck in the top right corner. Any idea why?


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2019 CX-5 GT-R
my 2019 just started having this odor whenever I turn the car on so reading up on some older threads.
this looks like a great one, unfortunately oP's images no longer show.
you could clean and disinfect your evaporator and the smell will go away for some time.
A proper ac spray would help and can be sprayed through the blower motor below the ac cabin filter.
Its highly unlikely your drain pipes are clogged so early.
2019 CX-5 GT-R
first off you guys are awesome!
My 2019 (54k miles) started doing this the last week or two and this video greatly helped.

I did notice the hose is slightly different on the 2018 as it didn't have that retaining clip on the top part of the drain hose.


I was able to get the kool-it line all the way into this hose and emptied the can into the line.
had some discolored fluid leak out of it into a container while I let it sit for 15 minutes so you could tell it was definitley cleaning it out.

After starting the car up it appears the smell is greatly reduced / gone but I'll keep an eye on it the next few drive cycles.

one interesting things is I drove the car around for about 10 minutes after cleaning (with that kick panel removed) and I did see a bit of water on my floor mats. Not much but dripping from somewhere.
The drain line doesn't appear to be clogged as it was dripping into a tupperware container earlier so maybe it's just some extra condensation / fluid that I missed earlier. Something to keep an eye on the next few days.