Musty smell from A/C..

[SlickMachine]

Anyone have any experience with this? So far I have changed out the cabin air filter and checked the air intake under the hood under the plastic cover where it resides- totally clean.
I get a wet/musty smell from the AC when I first turn it on. It is mostly only when the car has sitting in the sun and getting heat soaked, them when I fire it up and turn on the AC I get blasted in the face with that smell. It lasts for a minute and then goes away. To me it smells as if stagnant water is sitting somewhere in the duct system. I just sprayed pure rubbing alcohol into the intake while running the fan to see if that kills it but I'm doubting it.
Where are the drain lines for the evaporator and where is the condenser itself?

Sent from my Nexus 6P using Audizine mobile app

[ehofmann]

Spray lysol in the intake and run it on low for a few min. Then let it sit overnight with the windows down to help the lysol smell dissipate. I had to do it in my a4 and s4. Works great.


Sent from my iPhone using Tapatalk

[SlickMachine]

I think my drains are plugged.. no water on garage floor after running AC.

Sent from my Nexus 6P using Audizine mobile app

[SlickMachine]

Answered my own question: one drain line is located on passenger side footwell, against the trans tube. Remove small rectangular panel as pictured by popping off bolt cover and using 8mm hex drive.

There is the drain line attached to drain pan.

Turns out mine isn't clogged so ordered some 1Z to clean the evaporator.

Sent from my Nexus 6P using Audizine mobile app

[DaveG ASP3]

I was going to recommend the 1Z Klima Kleaner. I've used it on many cars - works great.

Sent from my SAMSUNG-SM-N920A using Tapatalk

[EriCal]

I have just started to get the odor problem in my 16 S7; one year old, 7k miles. I have had this on previous cars, once so bad I had the evaporator replaced. The smell is from mold that grows in the intersticial spaces of the evaporator. Some moisture remains there when you park the car, even if the drains are clear, and mold grows. While there are ways of combatting the mold, prevention is the best. That means, switching off the A/C a few minutes before you park the car and running the fans at high speed to expel the moisture. i.e. Don't put the car away wet. That mold CAN have an adverse effect on those with respiratory sensitivity.

[OmaHahn]

I have just started to get the odor problem in my 16 S7; one year old, 7k miles. I have had this on previous cars, once so bad I had the evaporator replaced. The smell is from mold that grows in the intersticial spaces of the evaporator. Some moisture remains there when you park the car, even if the drains are clear, and mold grows. While there are ways of combatting the mold, prevention is the best. That means, switching off the A/C a few minutes before you park the car and running the fans at high speed to expel the moisture. i.e. Don't put the car away wet. That mold CAN have an adverse effect on those with respiratory sensitivity.

You beat me to it! This is exactly how to combat this issue!!! Always turn off AC and let car run a good couple mins before shutting off to let system cycle through and expel moisture.

[SlickMachine]

I'm learning all this now. This wasn't an issue on my C6 that I had for over 4 years. I don't get it.

Sent from my Nexus 6P using Audizine mobile app

[SlickMachine]

I have just started to get the odor problem in my 16 S7; one year old, 7k miles. I have had this on previous cars, once so bad I had the evaporator replaced. The smell is from mold that grows in the intersticial spaces of the evaporator. Some moisture remains there when you park the car, even if the drains are clear, and mold grows. While there are ways of combatting the mold, prevention is the best. That means, switching off the A/C a few minutes before you park the car and running the fans at high speed to expel the moisture. i.e. Don't put the car away wet. That mold CAN have an adverse effect on those with respiratory sensitivity.

I believe that this could be the reason that when I arrive at work after 30 mins in the car that my nose itches and is runny. Seriously.

Sent from my Nexus 6P using Audizine mobile app

[wwhan]

Every night I park in the garage, with the front windows rolled down - no issue with mold.

[SlickMachine]

For anyone searching this issue like I was for the C7 platform, here's the solution:
KlimaClean is definitely the way to go because the smell from the cleaner fades almost immediately.
You need 2 cans (at least I did) to get it done right and completely kill the odor.
You need to empty one full can in the passenger side evaporator drain tube located on right side of center console (passengers left leg). See picture earlier in this thread. remove plastic cover to access bolt, pull small panel off to expose where evaporator tray connects to drain tube. This process is identical on the driver's side. Remove rubber drain tube connection from evap tray nipple. Grab some paper towels and place around the nipple to catch the cleaner because it will spill out. Insert tube from 1z KlimaClean into nipple, run in as far as makes sense, then attach to can and empty the can. When can is empty, quickly reconnect the drain tube so the product can drain out of the car. Repeat with second can on driver's side. Then follow directions on product and run fan for a few minutes to dry out system.
I originally only treated the passenger side and within a day the odor returned. I then ordered another can and hit the driver's side and that killed the odor completely. This way you are getting both sides of the evaporator with the KlimaClean. Happy to report that the smell is gone.

Sent from my Nexus 6P using Audizine mobile app

[AudiC7Owners]

For anyone searching this issue like I was for the C7 platform, here's the solution:
KlimaClean is definitely the way to go because the smell from the cleaner fades almost immediately.
You need 2 cans (at least I did) to get it done right and completely kill the odor.
You need to empty one full can in the passenger side evaporator drain tube located on right side of center console (passengers left leg). See picture earlier in this thread. remove plastic cover to access bolt, pull small panel off to expose where evaporator tray connects to drain tube. This process is identical on the driver's side. Remove rubber drain tube connection from evap tray nipple. Grab some paper towels and place around the nipple to catch the cleaner because it will spill out. Insert tube from 1z KlimaClean into nipple, run in as far as makes sense, then attach to can and empty the can. When can is empty, quickly reconnect the drain tube so the product can drain out of the car. Repeat with second can on driver's side. Then follow directions on product and run fan for a few minutes to dry out system.
I originally only treated the passenger side and within a day the odor returned. I then ordered another can and hit the driver's side and that killed the odor completely. This way you are getting both sides of the evaporator with the KlimaClean. Happy to report that the smell is gone.

Sent from my Nexus 6P using Audizine mobile app

Sorry to bump and old thread but I'm about to do this. The directions from KlimaClean say to remove the blower motor... will using this product as you described work since the blower motor is still in there?

[Dan GSR]

Run the heat on full blast before shutting off the car

[SHR]

I chased this same problem in my sons B6 A4 for a couple of years, until I discovered that I had issues with the 4 servo motors that regulate the airflow being out of synch, and I believe one of them was bad, I destroyed it trying to clean the pot, so I just replaced it. I throw this out there for you in case the issue continues to return. On the B6, I found a reset procedure that you perform by holding the HVAC control buttons in a certain sequence, and I also found the procedure to initiate it with VCDS, both worked fine. You can hear and watch the servo's actuate to each extreame and then find where they should all be in unison with the others. I assume they're designed to dry the moisture out in a particular sequence based on what the system is delivering. Once I got everything in synch the issue never came back and I haven't had to spray another can into the evap. I don't have time to research if this is similar on our C7 and hope this info is helpful.

[gk1]

I got one of these long ago and don't seem to have any problems.
https://www.frecious-plus.com/en