CX-9 Clogged AC Evaporator Drain

T

Teeger

Member
:
2008 CX-9 Grand Touring White
Late last year I had a sloshing sound in the dash of my 2008 CX-9. The sloshing sound continued to the point where, when I turned left (if I remember correctly), water would drip out of the evaporator case through the blower motor of the climate control system... and drip onto the passenger side floor. I eventually figured out where the evaporator drain is.

I've attached a photo. Take a look in the center "tunnel" underneath the truck. There is a silver heat shield in the tunnel, and the opening of the drain is behind it. The heat shield is bendable. My scientific solution was to bend the heat shield back, put a wet/dry vac on the drain, and bend the heat shield back into place. I'll bet almost a gallon of water came out.

Soon after my blower motor quit working. I took the truck into the dealer. They said the motor was fine, but a relay needed to be replaced. No worries since.

100_0648.JPG
 
Godd picture to let people know where it is. A few people on this forum have had this problem too.
 
Thanks for posting this picture and the solution. About a week ago I noticed water coming out of front footwells and heard a strange whistle while turning and found from searches that drian was most likely the cause. I crawled under and tried to work this spot with a coat hanger to no avaial but then grabbed a 12v air compressor for tires, balls ect... and plugged it in there for a sec then it drained real good. Well over a gallon in it.
 
First i would like to say thanks for the drain plug pic. Sadly i have had to do this 3 times in the last month twice in the last week. I am using a shop vac with a pvc elbow to make it easier to suck it out. My question is what else could be wrong that i have to do this every couple weeks? Any help would be great full
 
BUMP. Like tollboothwillie I have to do this WAAAAYY more often than is acceptable. Do others have the same experience? How can I actually CLEAN it out rather than just a short-term unplug?
 
tollboothwillie said:
Anyone? I am having to unclog again today my last post was the last time i had to unclog
Click to expand...

I've had most of my dash ripped out trying to get to the "tank" before I found the drain. It sounds like you have something more substantial in your tank than just some clogged up water. I used compressed air to blow mine in rather than vacuum it out. It's been fine for a few months now, but i have decided to hit it with the compressed air every time I put it up on the rack. I figure oil chnages, tire toations, etc, should end up clearing it 2-4 times a year hopefully. It sound like your drain hose is still mostly clogged. You might try to detach it and see if there is anything in there.

When I cleared mine for the first time, it drained water out for almost 2 minutes. Very poor design IMHO.
 
Teeger,

Thanks a lot for that post it was really helpful.

I did use a "The Blaster" compressed air for cleaning computer and it worked just fine.
 
Thanks for posting the pict. We had the exact same thing happen, my wife took it in to the dealer and they charged $95 to unclog it. I didnt have time to look into it and we couldnt allow the water to continue to builup in the passenger side. Now the question I have for this group. Now the carpets are soaked, what do you all recommend to dry it, the water is under the carpet, is there an easy way to remove the carpet? the car is starting to smell.
Thanks for your help.
 
juanV said:
Thanks for posting the pict. We had the exact same thing happen, my wife took it in to the dealer and they charged $95 to unclog it. I didnt have time to look into it and we couldnt allow the water to continue to builup in the passenger side. Now the question I have for this group. Now the carpets are soaked, what do you all recommend to dry it, the water is under the carpet, is there an easy way to remove the carpet? the car is starting to smell.
Thanks for your help.
Click to expand...

same thing happened to me, I didn't remove the carpet, I used this product :

https://www.amazon.com/dp/ (commissions earned)

and pressed it really hard against the wet carpet,

this thing sucked up all the water like there was no tomorrow, and carpet was almost bone dry,

then I set the air ducts to blow hot air into footwell to dry up what little moisture was left.
there was absolutely no mildew smell afterwards.

You can also buy it from any AutoZone or Pepboys, don't need to wait for Amazon..
 
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If it was me, id just remove the carpet, and let it sit outside face down in the sun to dry. No towel alone is going to do anything other then dry off the top of the carpet. It wont be able to suck through the carpet, down to the insulation which is where most of the water is held.

Ive never pulled the carpet on my CX9. But have on over a half dozen other cars, including replacing entire carpets on multiple. Its a pretty straight forward process. Typically involves pulling the seats, and the lower door sill trim. Ive even removed really dirty carpets just to bring them to a DIY car wash, and pressure washed the carpet. Its really not that bad of a job if you have a day to waste. Most of the day would just be allowing the carpet to dry.
 
I haven't looked into on the CX-9 yet, but on many cars, you can remove the blower motor and gain access to the evap housing by reaching your hand in there. On my Jeep Grand Cherokee, I had some leaves composting in there. Was able to dig them out by hand. The Jeep was provisioned for a cabin air filter, but the don't install them at the factory or at the dealer prior to delivery. So I would also check to make sure you're cabin air filter is installed.

Seeing that you're in Florida and almost certainly use the AC a lot, you probably have some mildew on the evaporator. If you can clean some of it off with a softer brush and/or compressed air, that will likely improve you airflow and cooling a little.

As for water under the carpet, I agree with Monoxide, once that jute insulation gets wet, it really needs to come out and get replace. Maybe the carpet is salvageable if you can pressure wash it and there is no smell left behind, but I doubt that same will hold true for the insulation.

Also, it's it been wet under there for a while, it may have started to rust the floorplan in places. So It's a good to inspect that as well.
 
I just had to do mine for the first time today. After 8 years and 106,000 miles. Had the bubbling noise from water sloshing and in left hand turn you could hear the water hitting the fan spraying in the box making a hissing sound. Jacked the car up and put the shop vac on it. Sucked out some dirt and about two quarts of water. Fixed for now. BTW there are TWO drains! One for the front box is the one in the pictures above and the second one is farther to the back on top of the tunnel. Seems these cars have two separate evaporators, one for the front and one for the rear controls. There are also a/c lines going into the body near the back drain. So there must be a second evaporator.
 
The Internet is a wonderful thing! Started hearing the bizarre sloshing sound every left turn this weekend. 10 minutes googling the issue and found the fix. I tried shoving a pipe cleaner up the drain tube first but it didn't work. The can of compressed air worked like a charm!
 
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ChrisnVA said:
The Internet is a wonderful thing! Started hearing the bizarre sloshing sound every left turn this weekend. 10 minutes googling the issue and found the fix. I tried shoving a pipe cleaner up the drain tube first but it didn't work. The can of compressed air worked like a charm!
Click to expand...

Thanks Chris, your can of compressed air trick worked for me too!
I heard the dreaded swishing water hitting the fan blades again every time I made a hard left turn,

the first time the dealer fixed it for free, I didn't want to be bothered with taking time off work again to fix the problem,
so I followed your compressed air idea and literally a gallon of water came pouring out,

I took a video for other members just in case the same thing happens to them,

first you need ground clearance to get under the car, can either jack up the car and use jack stands
OR use cement blocks as shown in Step 1 of this link (disregard rest of steps, that's for changing AWD transfer case oil)

http://www.mazdas247.com/forum/showthread.php?123847373-Changing-CX-9-transfer-case-gear-oil-%28photos%29

Once you have the car up, you have to bend back the heat shield to see the drain located on the vertical sidewall approximately under the driver's side
obviously the video is after the gallon of water poured out, but I just wanted to show how it was done.

this is the second time now in two years, horrible drain design, it gets clogged too easily (boom02)


 
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A very helpful thread so thanks to those of you who posted the photo and video as well as the descriptions. I followed the suggestion to use the compressed air and it worked very well. The big question will be how quickly it becomes clogged again and if there is still crud to be removed. Based on reports here, it sounds like many have seen a recurring clog; if you have successfully cleared it out by taking any additional steps after using the compressed air, I welcome those suggestions too.
 
I'm trying this today. I'm curious about the source of the clog myself. Is it leaves or other debris making its way in from some source near the bottom of the windshield?

Sent from my Nexus 5 using Tapatalk
 
So, it was indeed as described: a bending back of the heat shield, a two second burst of canned air and at least a gallon of water gushed out. The problem now: the AC barely blows up front (still good, strong and cool in back). Relay damaged or something else? Odd that it was just fine all clogged up.

Sent from my Nexus 5 using Tapatalk
 
tphillippe said:
So, it was indeed as described: a bending back of the heat shield, a two second burst of canned air and at least a gallon of water gushed out. The problem now: the AC barely blows up front (still good, strong and cool in back). Relay damaged or something else? Odd that it was just fine all clogged up.

Sent from my Nexus 5 using Tapatalk
Click to expand...

T - Turn off your Fan until you can check your blower motor. I wouldn't be surprised if the burst of air forced water up through the vent system and into the blower motor. If the fan was working fine before you did this, I would bet that you will find water in it. It's extremely easy to find and remove.
See this other thread for more details; http://www.mazdas247.com/forum/show...tor-Unfortunately-it-was-not-the-Blower-Relay

My fan was dead, but full of water - if you can drain yours before it shorts out, you probably won't have to replace it. Good luck!
 
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