A/C Drain Hole Location

**driv3n** · 06-23-2016 09:36 AM

Hoping some of you with a B8 could point me in the right direction. I have an annoying A/C musty smell issue that keeps on coming back. Back in April when the car was in for service I brought it up to the dealership and they did some sort of A/C clean/decontamination on the car. While doing so, they replaced the cabin filter as well.

Now it's only been a couple of months and the smell is back. Based on the countless threads I've read for this issue, people have mentioned to check the A/C drain to see if it's clogged up because that can cause the smell to come back quickly even after getting the A/C cleaned. Does anyone know where the A/C drain is?

Thanks in advance.

**IHave2Turbos** · 06-23-2016 11:02 AM

I would also love to know what the REAL procedure for using the klima cleaner is. I have seen where the drain hoses are (both sides of the center console).

Do you spray the klima cleaner up there to clean inside (basically up inside the dash?) or do you spray down the hoses (which i think will essentially spray down to the driveway).

I would think the former but I've only ever see a DIY that mentions spraying into the side vents and for me, this has done nothing to eliminate the smell.

If the vents do work, what do the vent distrubution settings need to be at to ensure the foam makes it to where it needs to be?

I also have changed the filter to no effect.

How do you clear the drain? Do you push something down from inside the cabin towards the driveway? Or is there a way to clear them from under the car?

I would love to get a definitive DIY answers on this procedure.

**JeriQo** · 06-23-2016 11:09 AM

Originally Posted by IHave2Turbos

I would also love to know what the REAL procedure for using the klima cleaner is. I have seen where the drain hoses are (both sides of the center console).

Do you spray the klima cleaner up there to clean inside (basically up inside the dash?) or do you spray down the hoses (which i think will essentially spray down to the driveway).

I would think the former but I've only ever see a DIY that mentions spraying into the side vents and for me, this has done nothing to eliminate the smell.

If the vents do work, what do the vent distrubution settings need to be at to ensure the foam makes it to where it needs to be?

I also have changed the filter to no effect.

How do you clear the drain? Do you push something down from inside the cabin towards the driveway? Or is there a way to clear them from under the car?

I would love to get a definitive DIY answers on this procedure.

i sprayed 3/4 of the can on the evaporator.
to get to it, you take the cabin filter off, look inside (its a PITA) theres an opening to get to it towards the driver side.
i sprayed the rest on the window vents.

idk... i think it just masked the scent.. now my car smells like vodka.

**The Infiltrator** · 06-23-2016 11:11 AM

Originally Posted by JeriQo

i sprayed 3/4 of the can on the evaporator.
to get to it, you take the cabin filter off, look inside (its a PITA) theres an opening to get to it towards the driver side.
i sprayed the rest on the window vents.

idk... i think it just masked the scent.. now my car smells like vodka.

lol

**IHave2Turbos** · 06-23-2016 11:43 AM

any chance you can get a pic of where you put the hose? Are you saying pull the filter (on the passenger side) and then look from the drivers side for the evaporator? did you actually see the coil/fins?

a kind of related question, I never see a water puddle under my car when the A/C is running. Is this a def. sign of clogged drains?

**JeriQo** · 06-23-2016 11:47 AM

Originally Posted by IHave2Turbos

any chance you can get a pic of where you put the hose? Are you saying pull the filter (on the passenger side) and then look from the drivers side for the evaporator? did you actually see the coil/fins?

a kind of related question, I never see a water puddle under my car when the A/C is running. Is this a def. sign of clogged drains?

Sent from my HTC One_M8 using Tapatalk

thats the cabin filter slot.
the white hose is the klima cleaners, the black is my android endoscope.
theres an opening inside that goes towards the drivers

**JeriQo** · 06-23-2016 11:53 AM

Originally Posted by The Infiltrator

lol

the fumes aint no joke man. i got a slight headache spraying that thing, i had to take breaks in between.

**IHave2Turbos** · 06-23-2016 11:58 AM

awesome thank you, that makes more sense now. much appreciated.

**driv3n** · 06-23-2016 12:03 PM

I've never seen any puddles underneath the car. Anyone have a picture of the drains? Definitely want to see if it's clogged.

**jfo** · 06-23-2016 12:26 PM

Originally Posted by JeriQo

Sent from my HTC One_M8 using Tapatalk

thats the cabin filter slot.
the white hose is the klima cleaners, the black is my android endoscope.
theres an opening inside that goes towards the drivers

Can you see straight through the blower fan to the evaporator?

**JeriQo** · 06-23-2016 12:32 PM

Originally Posted by jfo

Can you see straight through the blower fan to the evaporator?

im sure you can if you take the glove box out.
the instructions say insert tube in the middle vents but its blocked by a mesh --- cant get the hose through.

**jfo** · 06-23-2016 01:59 PM

Originally Posted by JeriQo

im sure you can if you take the glove box out.
the instructions say insert tube in the middle vents but its blocked by a mesh --- cant get the hose through.

I thought perhaps you could see it with your scope, to ensure you were actually reaching the evap. The instructions I've seen recommend removing the glove box so that you push the hose through the blower fan cage. I did mine by going through the window vents, alternating a few times from side to side. It helped but did not eliminate the smell. I will probably try another can at some point, and take the glove box out.

**S4'ed** · 06-24-2016 11:20 AM

The only way to prevent this smell is to let the HVAC system dry out....using the "Auto" function of the climate control, lets the AC run, even when its not that hot, to dehumidify. Unfortunatly this means that the evaporator is wet almost all the time, through-out the year...and that why the mold grows. Make a habit, when not needing AC cooling, to let the system run in "Economy Mode"(switch off the AC compressor manually), so that the system can dry itself out.

**driv3n** · 06-28-2016 09:44 AM

Anyone have any other sprays or solutions besides Iz einszett klima cleaner? I sprayed a full can and it seemed to make the smell better, but it's still there.

**JeriQo** · 06-28-2016 10:18 AM

Originally Posted by driv3n

Anyone have any other sprays or solutions besides Iz einszett klima cleaner? I sprayed a full can and it seemed to make the smell better, but it's still there.

people at the s4 section spray lysol at the evap and vents
i dont think ill be doing that

**meliqa** · 12-11-2016 01:53 AM

Hi all, as I see it is a big issue, to properly clean the ventilation and conditioner. Does anybody know how to properly disinfect air conditioning system on audi a6 4f. Despite regular filter change it smells, I have found some sprays at Berner and Würth, but they have no clue how to do it on Audi A6 4F. Any kind of feedback will be much appreciated. As far as I understand the best way is to completely dismantle the ventilation system and clean it, but, on A6 4F it means a lot of work. Any kind of advice will be super or any sort of DIY guide :)

**rally3** · 12-11-2016 11:39 AM

At the dealership I worked at we had good luck with this
https://www.bgprod.com/catalog/clima...g-frigi-clean/
it is a foam cleaner. that will coat the evaporator and ducts.
When possible you drill a small hole in the duct between the fan and the evaporator and inject it there, (has a cap for the fitting when done)
Then followed with
https://www.bgprod.com/catalog/clima.../#bg-product-4

But as mentioned above, turning the system to Econ to stop the compressor reduces the mold/bacteria build up....

**IHave2Turbos** · 05-11-2017 08:01 PM

can you post a pic of where to drill or a diy?

**rally3** · 05-11-2017 11:15 PM

these are the instructions for applying
https://www.bgprod.com/bg-master/upl...ns-English.pdf

Have not done it to my B8, So I don't know where to tell you to tap in.
Basically Just find a spot between the fan and the evaporator

**IHave2Turbos** · 05-12-2017 07:24 PM

that is the mystery! if you ever find out please let us know thanks.

**jfo** · 05-12-2017 08:08 PM

Remove the cabin filter and the evaporator is right next to the opening. If you have a mirror and light you should be able to see it clearly. I used my scope. You can fill the evaporator cavity with the foam through that opening. It is still hard to know if all the surfaces are exposed to the foam, but it's much better than shooting down the side vents.

**IHave2Turbos** · 05-13-2017 05:56 AM

Thank you. Are there any pics of the approximate location?

Also, is there any visible "drain" under the car? I never see condensate under the car when running A/C.

Does Audi recirculate it somehow or is my drain definitely clogged?

**jfo** · 05-13-2017 12:33 PM

Originally Posted by IHave2Turbos

Thank you. Are there any pics of the approximate location?

Also, is there any visible "drain" under the car? I never see condensate under the car when running A/C.

Does Audi recirculate it somehow or is my drain definitely clogged?

The evaporator case is directly behind the lower dash at the center console. The evaporator is only a few inches to the left of the cabin filter. The opening into the case can be seen if you lay on your back and shine a light into the filter slot. If you have a scope it's easy to see the evaporator. Outside air is pulled through the blower, then the filter , then directly into the evaporator case. You can direct the foaming wand into the case and move it around to fill the cavity with foam.
There are drain hoses on each side of the tunnel under the carpet. These short hoses are attached to the collection tray and then plug into an opening at the top of the tunnel, which then connects to the drain that exits the cabin. You could also put the foaming tube through one of these, but I think it's more work than going through the filter opening. I was under the car recently and noticed 2 nipples on the roof of the tunnel, above the drive shaft and exhaust pipe area....probably the outlets.