GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

Smelly AC. It's not the cabin filter

Location
NC
I have the smelly AC issue but unlike most of these threads, my cabin filter is brand new.

I've attempted spraying the intake duct with Lysol while the fan is on full blast and while this works temporarily, the smell comes right back the next day.

I know this is a mold/mildew problem but aside from fogging the car with fungicide, I'm not sure what to do. Plenty of threads say that the dealer has a fix but fail to mention what the fix is.
 

golfonsteroids

Passed Driver's Ed
Location
Singapore
Give this a shot mate.

When I was a cash poor college student, there were a lot of car maintenance and repair jobs I had to learn to do myself. I can change my own oil, install new brakes and even fix leaks. While I now pay someone to do most of those jobs, there are a few automotive repair projects I still choose to do on my own. My recent experience with a stinky air conditioner in my car gave me an excuse to dust off my automotive repair skills. Here is how I fixed my stinky car air conditioner.

What is That Smell?
If you have a stinky car air conditioner, you will know it. The smell is especially strong when you first turn on the air conditioner and permeates every inch of the car. The smell is similar to tennis-sock odor or mildew and is caused by bacteria, mold and fungi that grow in the air conditioner evaporator core, condenser hose or in the pan used to collect water.

These microscopic organisms grow because as the air conditioner is used, the cold air causes condensation to form that then combines with contaminants such as dirt, pollen, dead insects, pet hair, nicotine and tar from cigarette smoke and plant and animal debris. If the condensation doesn't drain properly due to a clogged tube or if the unit isn't allowed to dry out completely after each use, water can become trapped and stagnate. This allows harmful bacteria and mold to grow and cause odor.

A smelly car air conditioner should not be ignored; where there is odor, there is mold. The mold spores are easily inhaled by the occupants of the car causing allergies, sinus infections and asthma complications. Mold can be especially harmful to small children and anyone with a compromised immune system.

How to Disinfect and Deodorize the Smell
The first step in this automotive repair project is to disinfect and deodorize the car air conditioner. There are several odor neutralizers on the market that you can spray into the air conditioning vents or directly into the core. If you spray a product into the core, it is necessary to first drill a tiny hole into the top of the plastic heater box under the hood. If you don't want to go that route, I have had good results using a combination of Lysol disinfectant spray and drying out the car's air conditioning unit.

To disinfect and deodorize, set the car air conditioner to the recirculate setting. While the air conditioner is running, spray Lysol down under the dash where the front passenger's feet would be; the Lysol will be sucked up into the unit. Repeat this several times a day for a few days in a row. This will kill any odor causing bacteria. However, you should take steps to dry out the car air conditioner after each use to prevent the problem from recurring.

How to Dry Out Car Air Conditioner
To dry out your car air conditioner, turn off your air conditioner at least five minutes before you stop driving. Then, turn the interior fan to full speed. This will help dry out the entire system. Another way to dry out the system is to set the air conditioning to open circulation a few minutes before turning off the car. When you turn off the car, leave the controls set to open circulation mode. Before restarting the car, turn the air conditioner off so that the air compressor doesn't activate when the car starts. When you turn on the car air conditioner, always leave it set to outside circulation for a few minutes.

How to Clear Clogged Drain Hose
If you have deodorized and disinfected the car air conditioner, are allowing it to dry out after each use and are still having problems with a bad smell, the car may have a clogged drain hose. Another clue that the drain hose may be clogged is a wet spot on the passenger side floor. This is another automotive repair project you can easily do yourself.

To clear a clogged drain hose, look under the hood and locate a short hose coming out of the firewall on the passenger side. The hose is usually L-shaped and points downward toward the ground. This hose should be open and clear, allowing water to run out onto the ground as the air conditioner runs. If you are running the air conditioner and there is no puddle of water after a few minutes, then you most likely have a clogged hose.

To clear the blockage, use a chopstick, knitting needle or piece of wire coat hanger and poke into the hose to remove any clogged debris. Then run the air conditioner for a few minutes. If the clog is gone, you should see a puddle of water on the ground under the car. If you don't see a puddle, repeat the process until you have removed all debris from the hose and the air conditioner can drain freely.

Got this from yahoo voices.
 

dazzag

Ready to race!
Location
Spain
I have the same problem. I dumped in a can of Einszett Car Air Conditioning A/C Con Air Con Cleaner last week it helped a bit but its still there.

I've even been running the car without ac just blowers and the window open.

I suppose the car always being in the garage does not help. I do get some liquid coming out of the drain maybe i should check it anyway?
 

n_mcnelly

New member
Location
Maine
Car(s)
Mkv GTI
if you have a sunroof check to make sure your water drains aren't clogged also check to make sure there is no buildup on your vent located in the engine bay behind where the noise pipe is located.
 

brad1.8T

Ready to race!
Location
Sydney Australia
Make sure the intake plenum isn't full of leaves. Also remove all the leaves accumulated in the bottom of front fenders (where the mudflaps go) - this helps drain / dry the plenum.

Remove the AC fan & clear all the leaves & grey crap off the fan.

Do all the other stuff mentioned previously as well.
 

dgcamero

New member
Location
Charlotte, NC
Make sure the intake plenum isn't full of leaves. Also remove all the leaves accumulated in the bottom of front fenders (where the mudflaps go) - this helps drain / dry the plenum.

Remove the AC fan & clear all the leaves & grey crap off the fan.

Do all the other stuff mentioned previously as well.
^This! Also, the (Chrysler-esque, Valeo designed) system is an idiotic design and sucks in the air and then pushes it through the filter after the fan but directly before the evaporator. So for any Lysol to properly reach the evaporator, you have to almost directly spray the evaporator when you have the air filter removed (or it gets stuck on the fan blades and demisted for the most part).


Mine usually only smells stinky once or twice a year for a day or two, and largely goes away when I clean inside the outside air intake plenum, vacuum out the leaves in the fender wells in front of the driver's door (never get leaves in the passenger's side for some reason), and remove the fan and filter and get all the leaves, acorns, etc. out.
 
Top