KY.Benzster

I've done some research on this matter (here & Google searches) but now I'm coming to the pro's...

I have an intense moldy smell to my air conditioning and have tried the Lysol trick and even had Mercedes spray their chemical into my filters but the odor unfortunately still lingers. I'm going to personally attempt Lysol again before undergoing the more expensive fix but wondering where exactly our external vents are on the W212 (2010)? I know we have two corner vents on the corners of the windshid but are those the correct spots? Wanting to make sure I'm targeting the right places.

Also, if this doesn't work what is the exact part that needs to replaced and approx. cost?

Thanks in advance!

Live Oak

Aside from fixing the existing problem, you want to be sure the AC evaporator dryer fan is working.

After a drive using AC, park the car, and check it every few minutes. After several (up to 30-40) minutes, you should hear a fan quietly running --- and it should run for a half hour+. Listen at the outside vent on the passenger side. (The reason for the delay is that it is waiting for water on the evaporator to drain --- see below)

The purpose of that fan is to dry the evaporator so it doesn't grow the nasty stuff that stinks.

You also want to be sure that the drain from the evaporator is open so that water can easily drain out to the floor. That is water extracted from humid air by the cold evaporator. If you are in a humid climate, and don't see a big puddle on the garage floor after it's parked for a while, that could be the problem.

LEFAT1

When I worked for Volvo they had a kit that would be inserted into the evaporater and they sprayed a chemical that I believe disolved mold etc. Then a plug was installed to seal it off. I dont think this kit was specific for Volvo. Another experience I had was with a Prius and Lexus. On those forums I found a tip that worked quite well. After parking car, you would turn off the compressor and put fan on hi speed, similar to what Live Oak above had stated. Apparently this would dry up any moisture on the evap coils. I did this several times and the problem was gone. However, if the evap is not draining properly, there is likely a blockage and that might involve a trip to an A/C shop...

thefisch

When I did the Lysol treatment, I removed the air box under the hood so I could clean that out as well. Removing that will give you direct access to the blower motor from above so most of your spray will get in there. And it helps from getting Lysol on the top of the hood and windshield.

Despite multiple cleaning attempts, the smell would return. Changing the cabin air filter did the trick in the end.

F3LiX

MB has a can of this foaming contracept (Probably not how ya spell it).... but, if the smell is strong it never works. There is a new, more powerful chemical used with a tool that kinda looks like a spray gun with a long narrow pipe that reaches into your evap housing. If done right it works very well. Its sprayed through your evaporator core and then your AC is ran for 15-20 min. Then, with the same tool, water is sprayed to rinse the chemical and any left over mold out via evap drain. If the first attempt didnt work ask your dealer about which method they used. Just ask, is it the canned stuff or the stuff you pressurize in the tool..

KY.Benzster

Cabin air filter was replaced yesterday and another Lysol treatment to the filter afterwards....problem resolved!

sigx5

I turn A/C off before arriving the detestation (approx 2 minutes), never have this kind of issue.
However, it depends on where you live

mnje350

I have had this problem several times over the past 4 years with my 350. For the past two years, things have been OK. After the last cabin air filter was replaced. One thing that -may- help is to remember to keep the AC off when using commercial car washes. Some have said that they high pressure wash can force water into areas of the HVAC system that is undesireable. I have made a point to make sure that the systems are off when I use these types of washes. Dont' know if this helps solve the problem but for two years I have been stink free.

noka

I keep my climate system on "Auto" setting all the time. The AC is always running. Not sure if that helps to keep things dry but I'm comfortable all the time .

equetefue

I've had the issue with my Infiniti vehicles as well. What I have done and seemed to help is to turn off the A/C right before arriving to my house, rather than turning the car off with the A/C running.

Don't know why but it seems to work.

thefisch

For a while before replacing the filter, I tried turning off the AC and just using vent mode for the last few minutes. Then I always noticed the smell was stronger when I first put the system on. Now I just run the AC all the time. Perhaps it depends on the humidity where you live. Down here in FL it's constant.

noka

Never had a problem running AC all the time (and I'm in New England). Also keeps my windows from fogging inside with those high humidity conditions, which can also happen inside when a few people are in the car breathing all that humid air out . Did the same thing with past Benz's and BMW's and no problem,... but then I often don't keep a car beyind warranty. Time will tell.

Alex.currie44

Never had the problem. I never shut the HVAC off in car washes either.
I do change cabin filters every 2 yr. in both cars.