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water leaking on passenger footwell, accesing the evaporator?

128K views 49 replies 27 participants last post by  Benbr 
#1 ·
How easy is it to access the evaporator? There is water dripping on the passenger side foot carpet, maybe I can fix this myself before going to the dealer, don't have to time to drop the car off, etc.
What could it be anyway? A gasket or something loose?:8:
 
#2 ·
Jarek said:
How easy is it to access the evaporator? There is water dripping on the passenger side foot carpet, maybe I can fix this myself before going to the dealer, don't have to time to drop the car off, etc.
What could it be anyway? A gasket or something loose?:8:
It's usually a clogged drain line. Look under the car, passenger side, around the fire wall. Should be a small rubber line sticking out slightly. Try sticking a toothpick, or a thinned "Q-tip" in the tube to clean it out. If that doesn't work, it needs to be blown out with compressed air. Any garage can take care of that quick and easy.
 
#4 ·
Ok, got underneath and stuck a wire in the tube.. some water came out. I noticed the tube is rather low to the ground, anyone tried shortening it a bit? What could have gotten stuck in there so badly, a bug perhaps? :8: Didn't see anything fall out, just water..
 
#5 ·
Jarek said:
Ok, got underneath and stuck a wire in the tube.. some water came out. I noticed the tube is rather low to the ground, anyone tried shortening it a bit? What could have gotten stuck in there so badly, a bug perhaps? :8: Didn't see anything fall out, just water..
Is it the same as in the attached photo of my MY07? If so, then it does not extend below the bottom of the floor pan, and I wouldn't shorten it. It's possible that a bug was up there (the earwigs are plentiful this year and love getting into places like this).

If you have a wet-dry vacuum, you could try to bring the end of the vacuum hose to the drain outlet. It shouldn't take much vacuum to clear the hose of any remaining debris.

Where exactly is the water appearing in the passenger area?
 

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#38 ·
Yesterday, after driving in the rain, using the AC to defrost, the water leak in my 2006 Outback passenger foot well was dripping off the heat outlet onto the carpet, near where a passenger would have his left foot.

Footwell carpet was very wet, I shop vacuumed it out.

I let the car sit in the rain overnight, and this morning there was no water drippings on the rubber floor mat. (I put a tin foil shield to direct any drips onto the floormat).

fwiw, my sunroof drains are clear, confirmed by watching water come out behind the drains at each wheel.

This morning I started the car, and ran the heater directed at the feet (not defroster, but auto climate control on and AC is on in that mode) for 20 minutes, to dry the footwell further. No water drips showed at that time. I turned off the car, and let the car sit in my driveway.

About 1 hour later, my carpet is wet, and there is visible dripping from the heater area. (The car has just been sitting in the driveway, no actual driving, but it is still raining).

This made me think my AC dryer drain hose is clogged.


attached photo of my MY07
...
If you have a wet-dry vacuum, you could try to bring the end of the vacuum hose to the drain outlet.

Thank You for that photo!
I was able to find that hose and used a shop vac on it from the outside. Got a bunch of water out.

Im hoping this has cleared whatever was clogging the drain hose.

atm Im running a small electric heater, to dry out the footwell. There are no more drippings coming off the heater area.

will need to do some more testing, but Im very hopeful

ps, more evidence of the location of the leak, I removed the cover to the heater, under the glove box, (I put coins on the wettest spots on the padding for the photo).. in fact there was a puddle of water under that cover too
 
#6 ·
A bit more info:

The drain hose goes up through the firewall and connects to the bottom of the heater case.

The attached photo shows an exposed bend in the drain tube that is visible at the left front of the passenger foot well, just slightly left of dead center where the carpet, center console side panel and black lower cover of the glove box meet.

As far as I can tell by removing the glove box lower cover (which also incorporates the lower passenger side heat vent outlet) and following the tube with my finger, it is simply pushed up on a fitting on the bottom of the heater case. (Taking out the three push pins holding the glove box lower cover is enough to lower the cover for better access, but not enough to visually expose the bottom of the heater case itself.) If the water seems to be coming from that location, it’s possible that the tube has come off.
 

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#7 ·
That's exactly where the water is coming from. Do you mean the rubber hose has come off the evaporator itself? If that's the case, it looks like the whole lower dash below the radio would need to come off, right? I'll test it out and it it's still dripping, I'll have to bring it to a dealer.
 
#8 ·
When you say, “exactly where the water is coming from” are you referring to the drain outlet underneath the car, or the location inside the car?

The evaporator itself is inside the heater case. The hose connects to a fitting on the bottom of the heater case to drain the condensed water that forms on the evaporator inside the case when the A/C is running.

I was able to follow the hose to the heater case drain fitting with my finger without removing the lower glove box cover. It’s only an inch or two from where the hose is visible, but the fitting itself is not visible. The hose is shaped so this is an easy way to confirm if the hose is securely connected. (From where it is visible above the carpet, the hose goes up, right and then up again to the fitting. It appears to be a push-on fit without a clamp to hold it.)

If the hose is not connected to the bottom of the heater case, it might be possible to push it back on using just your fingers, but I have not tried it. If not, then I too would bring it to the dealer. (But if it is too easily slipped on the fitting then it might just as easily come off.)

If the hose was properly connected to the heater housing all the time, then the apparent blockage that you reported (e.g. an insect) is the likely source of the problem. Water would back up the hose and collect inside the heater case, where it would eventually find other ways to drain out.

If all the water in the hose appears to have drained out after your probing, you could bring a vacuum cleaner hose to the lower outlet and suck out any remaining debris. (A wet/dry vacuum would be the best choice in case there is still water in the hose.) The vacuum hose should not need to be tightly connected to the drain hose to accomplish this.
 
#10 ·
I have 07 OBW limited with 32k mi ... since last night and today found water dripped from front passenger side. I have the Huskies all weather floor liner so they all tucked within without spilling to the carpet. It is not much but enough to wet a couple sheets of paper towel. It is late that I found this page and know the location of this evaporating pan drian hole ... have to wait til tomorrow morning to unplug the hose. Thanks for the photo which is taken from 07 model, same as mine.

EDIT : "Mission Accomplished" ...
 
#11 ·
Could there be another explanation to this problem?

I have a 06 OB and in the last week it has been raining alot here in chicago. I have not used my AC since July, and well I have water that is coming from the same location as stated in the other posts.

I have checked and cleared the drain hose and the water still comes in. So yesterday I pulled the drivers side carpet, glove box, paneling appart to see if I can find any incling where it is coming from. I found out that it is coming from the heater core housing (I thought it was the core itself but wait it is clear not antifreeze) so I left everything open and drove the car to work and home and to work again. Now it has rained overnight so I thought I would see a bunch of water but to my suprise nothing.

Drove the car to work this morining with one eye on the road and the other on the bare passenger side and nothing unitl I hit a puddle doing 20mph while taking a left hand turn and a waterfall did apear in the car. Pulled over and again it is coming from the heater core casing. Drove it the rest of the way to work and to my suprise every left turn with a bump it would leak.

So I ask could it be that the car has a gasket leak or something is plugged in the engine area and it is causing it to backfill throught the cabin filter location?

I am at a loss and I refuse to pay the dealership money so they could tell me that they can not find the culprit.

To be Continued.......
 
#12 ·
roaringsx said:
Could there be another explanation to this problem?

I have a 06 OB and in the last week it has been raining alot here in chicago. I have not used my AC since July, and well I have water that is coming from the same location as stated in the other posts.

I have checked and cleared the drain hose and the water still comes in. So yesterday I pulled the drivers side carpet, glove box, paneling appart to see if I can find any incling where it is coming from. I found out that it is coming from the heater core housing (I thought it was the core itself but wait it is clear not antifreeze) so I left everything open and drove the car to work and home and to work again. Now it has rained overnight so I thought I would see a bunch of water but to my suprise nothing.

Drove the car to work this morining with one eye on the road and the other on the bare passenger side and nothing unitl I hit a puddle doing 20mph while taking a left hand turn and a waterfall did apear in the car. Pulled over and again it is coming from the heater core casing. Drove it the rest of the way to work and to my suprise every left turn with a bump it would leak.

So I ask could it be that the car has a gasket leak or something is plugged in the engine area and it is causing it to backfill throught the cabin filter location?

I am at a loss and I refuse to pay the dealership money so they could tell me that they can not find the culprit.

To be Continued.......
I believe you need a longer flexible wire to reach the blocked location until the water starts come out from the drain tube, or try to blowing compressed air from the tube end. Water is staying on the drain pan so the turning makes its spillage.
Front Defrost will auto turn on the a/c, that you may not aware of.
 
#13 ·
roaringsx, I have the same problem. I noticed a wet (and smelly) passenger floor mat a few weeks ago after it rained and thought the door window must have leaked or something. Today, same problem, absolutely soaking floor mat. I pulled the bottom of the dash down (the trim piece and the sound insulation were soaked) and found water drips from what appears to be a seam between the fan unit and the unit that directs air to the vents. Most everything else was dry. I will check out the drain tube, but I don't know why this is not a problem in the summer with the A/C running (and I do notice the drain tube draining underneath the car) but it is a problem when it rains.

Also, I undid the leaf guard on the cowl and felt around in there -- you can reach the cabin air filter that way -- bone dry, nothing at all coming in there. All plugs in the firewall seem to be solid, not wet, plugs on the passenger compartment side of the firewall also appear to be well sealed and dry.

It really seems to come from either inside the air director unit or somewhere above the whole HVAC system, dripping onto that "seam" I mentioned.

Any knowledge about this, suggestions, anything other than tearing the dash out would be great to know. This isn't a problem I can live with. The odd thing is, the car is over 4 years old and I have never noticed this problem before... :8:
 
#14 ·
One more thing to see if those with this problem have in common -- we have had our windshield replaced about 4 times (when we lived in AZ, everyone seems to have their windshields replaced often there). Does this only happen in cars who have had the windshield replaced?
 
#15 ·
I don't know why this is not a problem in the summer with the A/C running (and I do notice the drain tube draining underneath the car) but it is a problem when it rains.
Running the a/c (includes using defrost even though the a/c button is not pushed) when it is raining might generate more condensate than on hot, even high humidity, days. It could just be a matter of volume, especially if the blockage in the drain hose isn't 100% (which is a good possibility).

The joint between the fan air duct and the main box is a natural place for the overflow to come out. The water will collect in the main box under the evaporator. Making a left turn would tend to push the water toward the right, where the joint is located.

I doubt it is a result of changing the windshield, especially if the water is coming from that duct joint. A leak at the windshield would not be from inside the heater duct.

Making sure that the drain hose is clear should be the first step. As has been suggested, blow air up into the hose from below-- but not too much pressure to avoid dislodging the hose from the outlet at the heater box -- (or use a wet-dry vacuum to suck downwards). If you are in quiet are, it should be possible to hear the air rushing out into the heater box (with the car door open).
 
#16 ·
Well after 4 hours of tearing components out and well alot of swearing I came to a couple of conclusions about this issue.

1. Only take your Subaru to the dealer if you do not know how or do not want to work on your car
2. Bad placement of hoses and equipment will make issues like this arise
3. Putting electronic equipment under components that leak fluid is a big no no.
4. Blow out drain hose every oil change

I think the reason my floorboard was soaking wet and there was water coming from under the dash (ie, heater core, vents, switches, and any piece with a crack) is because the last time I took the car to the mechanic, aka Subaru dealer aka Satan for this exact same problem I come to find out that they forgot to put the drain hose on the pan my opinion. So tearing the whole compartment was not a loss. I did find out that water can leak in from the vent where the car gets it's air from under the leave guard under the hood but that would mean that the drain holes will be clogged.

After ripping the entire passenger area out of the car to find the leak I found out where the ECU is located, ironically it is under the kick plate on the passenger side of the floor board right under where a lot of water will collect is you drain hose clogs up. Also who ever designed the heater core unit mounting casing should be shot as there is one bolt that is at the top of the dash that only a 7 year old can fit his hand in there and if he does it will take him 15 minutes to unscrew.

This is still to be continued because I left the passenger side apart just to make sure that this was the culprit and it is supposed to rain tonight.

More to come.....
 
#17 ·
they forgot to put the drain hose on the pan.
Perhaps. But perhaps they used too much air pressure to clear the drain hose from below and blew the hose off the pan fitting.

My preference is to use a wet/dry vacuum to pull whatever is in the hose down and out. This ensures that the hose will not be inadvertently dislodged from the heater box. It also removes the blockage from the system rather than blowing it up into the heater box where it might eventually flow back down and block the hose again. (Of course, it does risk drawing something into the hose that gets stuck in the curves. But I doubt anything that large would be in the heater box, as long as the cabin air filter is maintained and intact.)
 
#18 ·
Soaked carpet yesterday

Yesterday, I happened to go out to the parking lot to get something from the car and realized when I opened the passenger door that the carpet under my all weather mat looked strange. A quick inspection revealed it was saturated! so much so that I had to use the shop-vac when I got home and the underside of the carpet is still wet.

I blew out the drain hose after verifying that it was connected and drove the car 55 miles this morning. No leaks. Drive back 55 miles this afternoon and no leaks until....mile 49. Total volume was only a couple of ounces, but frustrating nonetheless.

So tonight I removed the top section of the hose and blew it out from the top down. Took it for a short drive and then let it run a few minutes in the driveway. Will check tomorrow for more water.

Side note: When I removed the plastic cover with the sound deadening material from under the glove box, it was soaked, puddled and starting to discolor in a couple of spots. This leads me to believe this is not the first time this issue has occurred. :mad:
 
#19 ·
Let us know. It's possible blowing from the top down cleared the blockage. But there's a chance that the blockage was in the heater box fitting that the hose joins, in which case it might reappear.

With the plastic cover under the glove compartment removed, is the fitting on the box in full view? I posted a pic of the area (post 6 above) but didn't take down the cover and could only feel the end of the hose on the fitting. If it is, can you post a pic?
 
#20 ·
Wanted to update on this post: I got our drain unplugged. I think it was really just a small rock in the drain tube, but I'm not sure.

The first thing I did was blow some compressed air from a can up the tube. A tiny road pebble (so small I wasn't sure how it even was stuck in there) came out and a small puddle of water (not the stream I was expecting). Unconvinced that this was it, I took a vinyl-coated length of cable from Lowe's and used it like a snake to go up the drain hose. I couldn't get around the sharp bend into the passenger compartment, so I went in from the other end. I took apart half the dash (it's really a pain -- center console had to come out, shift boot, trim around the radio) to get the other end of the drain hose off the HVAC unit. I snaked it all the way down almost out the other end. None of this created the expected huge wad of gunk or rush of water (considering the seeming gallons we could get in the footwell), so I put it all back together and hoped for the best. And I have got it -- not a single drop in the footwell, even on the hottest, most humid days. I think it was that tiny rock that I got out at the beginning.

So...as was suggested earlier in this thread, blow out the hose routinely, or at least do it at the first sign of leakage in the footwell.

By-the-by, guess what's under the carpet in the passenger footwell? The frickin ECU! Crazy. It could have gotten soaked under there. Plus, if Subaru had located it somewhere else, there would be about three inches more foot room for the passenger! But I'm sure they had their reasons for locating it thus. :)
 
#21 ·
Just finished removing the passenger seat and the carpeting that was soaked like a sponge. I couldn't believe the amount of water I shop vac'd out of the carpet and underneath. Even under the carpet there is a thin layer of material that is attached (bonded?) to the metal floor that also managed to suck in water. The shop vac directly on it pulled out more water and then after waiting a bit, more pooled in the indented areas.

Not having the time to remove the rest of the interior and console (and not really caring at this point with 150k miles on the original tan carpet, I just took out the utility knife and cut the carpet just below the back seat.

Once I feel I've definitively solved this problem, I'll order up a replacement carpet in black and make a day of installing it.

The last time this happened, I never found anything actually blocking the hose nor did I get any significant flow of water once I blew it out with compressed air. This time around the first indicator that something was wrong was a musty smell after a particularly warm day and condensation on the inside of the windshield.

Will blow the line out again and see how it goes. I never once had this issue in any of my Audis and each of them went well beyond 165k miles before I sold them and bought something else. Would've left the passenger seat out but the damned airbag light and chime stays on when the seat is uplugged. :mad:

Will post an update once I have more to report.
 
#22 ·
I was having the same problem. Periodically noticed about a half gallon of water on the passenger floor. I definitely could not say it was coming from some sort of rain intrusion.
I never did pay enough attention to see if it was coming from my ac or defrost. Today I read this post, laid down under the car with about a 2 foot length of wire, and snaked it up the drain hose. About 6 inches in there was a flush of water out of the hose (maybe 4 or 5 ounces), and I have to believe my problem is solved.
 
#24 ·
Seems to me that most cars have a similar drain arrangement, so it's puzzling if the others don't tend to eventually block.

As far as the hose being prone to blockage, I think it might be, in part, due to the flow of air through the hose. When the HVAC fan is on, and the mode control is set to bring in outside air from the inlet below the windshield, most of the air exhausts into the car through the cabin vents. But some of the air also goes out from the HVAC airbox down the drain tube. This is because the HVAC airbox is at a higher pressure, due to the fan, than the pressure outside. This air helps move the water coming from the evaporator (when the AC is on) down the hose, and at the same time, it prevents dust and dirt from getting up into the hose.

However, when the mode switch is set to recirculate the cabin air, there's normally no pressure differential between the HVAC airbox and the end of the drain hose. When the AC is on, the water flow from the evaporator is no longer "assisted" by the air flowing down the tube as is the case when the mode is not set for recirculate.

In addition, because the car has continuous flow-through ventilation (there are air exhaust vents at the back), at speed the air pressure in the car can drop below the outside atmospheric pressure (again, when the HVAC is set for recirculate). If this happens, air can, I believe, flow up the drain hose into the cabin, thereby making up for the air drawn out at the rear flow-through exhaust vents. But this air coming in will also carry in dust and dirt, and if there is water in the hose at the same time due to the AC, it could form a mud (sort of like plaque in human veins) and eventually block the hose.

If the car doesn't have a cabin filter, this situation can also occur when drawing in fresh air, because dirt in the fresh air will mix with the water at the evaporator and flow down the hose, where it might collect at bends in the hose, or as some of the water dries.

What would be interesting is to see how the "other" cars' drains are set up that seems to make them so different.
 
#25 ·
Bought the car certified used from the dealer with only 17k miles.. and had this happen two weeks later while using the window defroster! What a nightmare! Luckily, the pictures on pg. 1 of this thread guided me through the problem quite nicely. Rolling the hose through my fingers and using a shop vac to suck the open end made an amazing difference... now it looks like I have several cups of water on the garage floor! After running the car at home, I was able to verify that water was steadily dripping out while the window defroster was running. Seems like the drain hose has several sharp angles and a long horizontal section that enable gunk to get caught rather easily. I was able to lessen those bends by pulling on the hose from below and wrapping the tube with duct tape to keep it from pulling back up through the firewall. I'll let the car dry overnight and give it a nice long test tomorrow to see if that did the trick.
 
#26 ·
Probably best not to pull down too much. The upper end of the hose is only slipped onto a fitting on the the evaporator housing. As there's no clamp or anything holding the hose, I would imagine that tension on the rubber hose from below could cause the upper end to move and perhaps come off.

I think that once the hose has been cleared and is working properly, you should be fine if it is periodically checked -- I do the vacuum routine at least once a year, and check every so often for the tell-tale puddle underneath when the AC is running.
 
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