Smell when starting AC
 

I have noticed a very bad or mushy smell when I start my car with A/C off( after I have shut the car for sometime and the AC was running when i shut the car).
This gets better in 10-15 seconds after I turn the AC on. The smell is a very strong smell of moisture with stangnant air....
Does anyone have the same experience?
I am worried as it might be a problem with my cabin air filter.
My car is only 3000miles on it.
Thanks

Had the same problem on a c230. Turned out to be a bad cabin filter....

Did the problem started so early? I mean I barely have 3000 miles on it....

There may be some mold growing in the humid environment of the A/C chamber--this was quite common in European cars in past years. Auto parts stores carry aerosol cans of a disinfectant that you spray into the A/C intake. Your dealer would probably do the same thing, at least for the first try at fixing the problem.

All cars do this to varying degrees. Its mold od sort. Have to open windows once in a while and drive with recirc off. That usually helps. Older cars cabin filter most likely. But its the venting that is most often the problem.

My GLK has this problem and I was worried that the New ML has it considering that I am considering to trade for it. I have replaced the Cabin filter several times to know that the mold is in the actual AC ducts not only the filter. Spraying disinfectant into the A/C intake will temporary fix the issue. I am yet to find a permanent fix.

Could it have anything to do with where the air conditioning condensation goes? I ask because I looked under the car the other day and there was no condensation dripping down. I asked this same question at another forum where other ML owners noticed the same thing but no one has come up with an answer. If the condensation is not dripping out of the car where does it go? And if it indeed "goes" somewhere, maybe that tank or whatever it is might be starting to smell. I've only had my ML350 a month but it has been hot here in Texas and the air has been on every time I've driven it since the day I brought it home. It does a great job of cooling but I still can't figure out where the condensation is going.

It's a great point as I have not seen the condensation going out anywhere . It well may be the tank that gets mold and smells bad ... I sure will get to service soon

That's the MB signature smell. All MB's have it, even my 300D has it! ML with 5k miles has it... Even my neighbor's AMG S63 has it. Certain people notice it differently. I find it some-what comforting.

My wife just came back from the dealer & asked about the exact same question. They said all European/German cars have the same problem & that's it's "normal".

Guess it's the Euro stink...

Yes, please let us know what the M-B service department tells you as to where that condensation is going. As I said a couple posts ago, I do not notice it dripping down out of the car at stand still but I have not yet notice the smell you are talking about. My fear is that I will - eventually.

There are several TSB's on bad smell on the "older" ML's and several other MB models. I am thinking that these new ones are following the same path? Usually fixed by taking apart some part of the dash near the AC system and cleaning and spraying the area with their special MB spray.

"special MB spray" to get rid of the "special MB smell"

smoke and mirrors

Of the 5 MB's I've owned only 2 of them did it. I too have heard the old "they all do it" reply but when I dug deeper the bottom line was (on my 06 ML) there was some kind of cleaning that they did in the air conditioner innards, sorry I can't be more specific, and then I was told another fix was replacing either the condenser or the evaporator, again this was last summer and I don't remember which. The latter was a all day big buck job and I was told the extended warranty would not cover it. I have an old 89 Chevy P/U with air and it has never stinked. One would think that this would not be a problem with a quality vehicle like a M-B.

MB standard answer = its normal.

Just curious, do any of you have or know someone who has an S-Class and if so does the A/C smell?

the MB smell is analogous to cigar smoke, some people hate it; other's find it comforting.

I've seen condensation leak on our driveway

Try to run the system with a/c off for a few minutes each time before shutting down for extended periods.

Is it on a 2012 ML 350?

Here is what some one recently posted at another site:

"I contacted M-B customer care to see what kind of an answer I'd get. Here it is...

Thank you for contacting Mercedes-Benz, USA LLC.

This is normal on your 2012 ML 350.

Sincerely,

Francine AC.
Case Manager
Mercedes-Benz, USA LLC."

So what do they tell the other 2012 ML owners who do see the condensation dripping?:rolf:

Good question. I will have to call service myself because I want to know where the condensation is going. Do they have some kind of super compressor on these cars that vaporizes the liquid? Every car in the fifty years I've been driving has to cool by compressor, which by its nature must leave a liquid by-product. I want to know where that by-product goes.

I got the same question...where is the water going???

That smell is NOT "normal" for such a new car. There's definitely something wrong with it. Go to a dealer and force them to check your AC system - the cabin air filter might be damaged or improperly installed, the condensate drain might also be clogged or improperly installed at factory or damaged by something else, etc.

Surely people have heard of legionare's disease.

Funny you mention that. I worked at the Bellevue after the outbreak. There is a ghost on the 12 floor that all the employees have encountered.

Here is something a person posted at another forum as to where the air conditioning condensation is going: "OK fwiw here's one svc dept answer - there are body panels underneath the drain for the A/C (noise reduction, aerodynamic, that sort of thing) - the condensate drains onto the inner surface of the panels and is evaporated by airflow when the vehicle is in motion - only prolonged sitting and large amount of drainage would result in piddling like a Harley on the ground. Works for me. No fancy recycling of condensate or anything like that. Case closed for me".

It seems to me that the smell is generated from within the system itself. If the water is indeed draining onto a panel or where ever, then one would think there should be no smell. If I were going to Star Fest it would be interesting to take a mason jar filled with the air conditioning aroma and put in on the table where the M-B big wigs sit and explain to them that this is what their $50K + cars smell like.

I've the same experience on my c class. Do you use the auto function of the AC? Also, always let fresh air in while the AC is on.

What you can do now is to clean the AC and replace a new filter.

I always use the auto function . How do you let fresh air in always? I never use the button for circulating air inside only.
Thanks

Finally got a chance to go to the service center. They accepted the smell was real and changed the cabin filters and dual filter ( something that nature ). Initially wanted me to pay indicating that it's a maintainance issue and not covered warranty, but I showed my extreme unhappiness on this remark as the car is hardly 3000 miles old. Then they agree to do it free of cost to me. It saved $200 from my expenses.
So far no smell, but will watch.
I was told the super condenser which gets the drainage needs drying on and off, and they recommend me keeping the car few hours out in sun once in a while. They also told me that they have noticed this in those cars parked in garages( mine is 100% times). Wearied ...

Auto function can allow fresh air in. That's fine.

I do the AC cleaning and replace the air-filter and the smell is gone. But it comes back around 20000km

For real!! Lol

ML 350 Bluetec Smell
 

I’m having the same problem since the day I drove off the lot. It’s been in the shop three times and I still have the same horrible smell. It’s beyond ridiculous I am going to hire an attorney to get out of this lemon. No water drips out while the AC is on I think it is collecting somewhere and its creating mold. Someone needs to bring this to light I'm getting sick head aches everyday now. I have never had this problem with any other car I've owned Mercedes-Benz for 20 years and this has never happened before.

AC smell
 

This occurred on my W164 after a few years, not yet on my W166. The problem is moisture on the coils growing things. If possible, try to turn off the AC a few minutes before turning off the car to dry the coils out. I must say, this has not been an issue on my two BMW M3s or other cars, so not sure what is different.

Have had this on MANY MB products including my 07 S550 and 12 ML. Issue is always the condensor needs to be cleaned out. Have NEVER had this issue on any car other than MB product. No excuse for it in my mind. My 2001 Range Rover has never had to have the condensor core cleaned and has no odor to the AC whatsoever.

I'm getting the same smell at start up.
Get this really foul smell at start up that lasts for about 15 seconds.

We have had this vehicle for 9 months.
This started once the weather started warming up in May.
The other issue is that this odour seems to have permeated into the vehicle and whenever we get into the vehicle there is a trace of this foul odour in the car.

I've been to the dealer twice for this issue. The problem I have is that both times we haven't been able to reproduce the smell.

They have sprayed whatever they use into the AC system and there's still no improvement.
To make matters worse, the dealer is claiming this is not a warranty issue and has charged me for this "service".

This is our second ML. First was a 2009 which never had this issue.
I have never had a previous or current vehicle with this issue.

It's bad enough that unless this gets resolved I will be trading in this vehicle soon, which is not something I would want to do. I think its a great vehicle otherwise.

You've got growies on the condenser coils. I've had it happen on other vehicles, but not this one yet. Ask if there is a more complete cleaning process that can be done. Helps to turn off the AC a few minutes before you turn off the car when you can.

This is the annual stinky air conditioning caused by, as Greg said, crap on the condenser coils. Unfortunately, at least for me, it only happened at start up after the vehicle sat for several hours so unless the vehicle was left at the dealer the problem could not be duplicated. So I took a large mason jar and filled it with air from the conditioner right after start up. Took the jar to the dealer, opened it up, and there was no longer any doubt about the smell. Now this was on my old '06 and it really hasn't been hot enough long enough here yet to see if the problem exists with my '13. Good luck with yours. I remember the maintenance guy said to spray a Lysol type product into the air intake with the air conditioning on but I don't know the merit of that as I sold my '06 before I tried it. Again, good luck.

PS, Go to the Mercedes web site and sign into 'Owners On-Line". I have asked them a few questions in the past and they always got back to me. Perhaps they can give you some new info on the problem.

I owned a S550 for a couple of years - there was a very slight smell at startup, but hardly noticeable.

My new ML550 however (with 4000 miles on the clock) smells somewhat like musty vinegar for about 30 seconds at startup, MUCH worse than the S ever was.

I live in Colorado, it's a pretty dry climate without much humidity most days, so I don't believe atmospheric humidity levels or mold is part of the problem. Also, I only get the smell after I've been driving the car recently and then parked for a little while. For example, while I've not noticed it when starting up in my garage (typically 70-80F), once it's been parked at a shopping center in the sun for an hour (90F day) it smells really terrible - so bad I have to open the window to let fresh air in.

2c

I've experienced this issue with many of my M-B's in the past, and also with the '12 ML. Dealer addressed citing Bulletin LI83.00-P-051588. They replaced the cabin filter, no charge, no discussion. Problem has not recurred.

SMELLY AC in my B200
 

I had a really bad problem with musty moldy smell and the car only has 20,000 km on it stored indoors. It was getting really bad. It was hard to be in the car with AC on or off.

I read this thread about leaving the AC on automatic. The B200 does not have automatic so I tried leaving the AC on all the time and adjusting the temperature when I needed it warmer or cooler and I never turned the AC all the way to the coldest setting.

I drove the car this way for a few days and the smell seems to be gone! Today I even turned the AC off and it was still odor free. :zoom:

My '01 ML did not stink, my '06 did, my '13 does not. Go figure!

My 2012 ML also has the ac odor when the ac compressor is off. When the compressor is on there is no foul odor.

While previous cars I have owned, including the 2011 ML had an ac smell it was no where near as bad / foul smelling as the odor is in the 2012.

I'm going to give Greg's suggestion a try.

I am also having the same smelly socks issue. This is a shame to have such a thing and hearing my 14 years old son's complaints, humiliating my car. This smell is more than ever with the car's eco start and stop feature, as it increases when you turn off the compressor. Even worse, we smell this smell every day for hours and what if it is harmful or worse causes cancer!!!

I'm also have smelly socks at start up for about 30 seconds, going to the dealer now and will leave it with them until fixed.

I recently had a dealer claim this isn't a warranty covered issue. This is pretty disturbing to hear as it appears to be a pretty common problem. I had hoped they'd do the right thing and fix my issue.

Has anyone had this issue and complained of it within warranty? If so, please PM me. We need to look into our alternatives here. Thanks

I had this taken care of a couple weeks ago under warranty. Car is only 9 mths old and 6000 miles on it. Service advisor said this is a common issue he has seen and MB recently changed the service interval on the cabin filters from every 20k miles down to 10k. Dealer changed both filters and disinfected the system for free.

I had this problem on a Lexus a few years back. The problem was with the charcoal cabin filter. Lexus eventually changed the part from a charcoal filter to a woven hepa filter due all the problems they were having. I suspect that the same thing is happening here.

I had this problem with a Lexus RX 400h and now my 2013 ML 350 Bluetec looks like is going to start a little bit of smell at ony 1,400 miles.

I know I have a very sensitive sense of smell, but the smell is there, even though is not so strong at this moment and others are not bothered by it...yet.

Same problem here. It's irritating for me and embarrassing when I have someone in my car and turn on AC.

I trick I sometimes use in all of my cars is to:
Turn A/C off
Temperature set to the highest setting
Fan set so high
leave on for a few minutes

This helps to dry out any moisture or bacteria in the system which can cause odors.
It is also a good idea to always turn off the A/C a minute or two before shutting the vehicle down.

Are we driving Yugos? I've never had this problem with any car. My first MB though.

Yugos stunk all by themselves. They didn't need any standing moisture in the evaporator. :rolf:

I love how we have to crack a safe combination to keep the AC from not smelling. I've attempted the codes listed here and they don't work. At least I don't have to safe crack my brakes.

This can happen to any vehicle under the right circumstances. I have not had the problem but I understand that a dose is antiseptic in the air intake will do wonders to prevent this from happening or help to cure it after is does.

Foul A/C Oder
 

I have this smell also, I just got it back from Service they said they replaced the cabin A/C filter and did an evaporator core cleaner, so far smell gone, we will see how long it last...

musty or mildew smell
 

.......I have a 2007 ML 350 I tried this air vent spray called..Clean Air..from Amazon CA-300...directions are on u tube and on the can...I tried it seems to work really well...

Lysol works really well too.

I have had the dealer at Lexus spray a liquid into the intake vent in front of the windshield to cure the odor in the ac blower box. It is quite common and can happen to even near new vehicles.

I have the issue on my 13' ML550, first time I brought it in they sprayed something into the system, it just made for a slightly perfumy dirty sneaker smell. I'm bringing it in again soon for another try. I've never experienced this on any other vehicle.

I have encountered this from my side in two ways - one is where the Climate temp control is set on full low - and left on full low for more than 10 minutes often for the full drive - which in turn does not allow the climate control system to breath or drain properly - I have also encountered this when cabin filters get "clogged" especially in area of high pollen - where the cabin filter is doing what it should do but gets over whelmed.

For DIY'rs - the "spray" of my choice is Einzsett Clima about $22 from Amazon:

2013 ML Smelly Socks Smell
 

Dealer swapped out cabin air filters to "fix" the same smelly socks problem I've been having since car was new. Mercedes indicates this is the fix, and is no longer covered under warranty (maintenance issue?). However, as we all know, the filter is BEFORE the evaporator box which is creating the smell, so swapping out the filter has no effect. Dealer has indicated that they have had this same complaint from a number of customers, so it is indeed a real issue, but Mercedes was just denying it. One temporary fix they have is to spray a foaming agent into the box to clean and kill everything in there, which they have done in the past with other clients. Problem with this technique, it doesn't solve the inherent design problem, and it dissolves the Antimicrobial lining that MB put on these newer evaporator boxes to apparently address the known problem...so that isn't a good option. However, last time I was in there a few weeks ago, the Service Manager indicated that MB had recommended a new fix to them for recurring complaints...something about taking out sound deadening, and certain body plugs to allow more airflow? This is my first MB, and I have NEVER experienced this issue with any of my previous autos over the last 3 decades (Honda, Ford, Mazda, Porsche). I'm embarrassed to take people in my car in the summertime as they have to deal with the foul odor for the first couple of minutes. Kinda sad I dropped $80k on this luxury auto and have to deal with this. MB better figure this out quick and rectify or repeat buying will be hindered. Anyone who rides in the car won't be buying a MB anytime soon either as I apologize for the "Mercedes Funk".

Suggestion folks...KEEP COMPLAINING to your dealer about this, and ensure they log the complaint in the MB Service System. MB will only know of this widespread problem if their service systems show it. EACH time I'm in there for anything, I have them log it so I have a record of the complaint in the event MB figures out the solution so I can have it covered under warranty, and it flags the issue in their system. Dealer indicated they like this method of constant complaining as it helps them push MB for a solution as well. Happy clients = happy profitable dealer. SO KEEP LOGGING THE COMPLAINT EVEN IF NOTHING IS DONE TO FIX IT!

I have seen this problem - where the driver sets temp on max-low - leaves it there - then during the drive the evaprator coil "frosts up" - and then at the end of the drive - driver exits and the evap frost melts - leaving a damp and dark wet/damp chamber - and that's when the "moldy sock smell" develops.. Einszett Klima will solve the immediate problem and modify driver temp protocol... last 4-6 instances I ran into over the past few months - every one was solved with the "fix"... when you run the temp control too low, and evap frosts up, the longer the drive the more inefficient the air con system becomes to boot.. self-fulfilling .. set too cold, frosts up, less efficient, set colder, finish the drive, frost melts, moldy sock... over and over again..

Had this problem before on my c-class and what fixed it is cranking the heat to hi 5 minutes before my destination and push the auto AC button. When the AC blows out hot hair for 1 minute then I shut-off everything. Never I had anymore smell afterwards. Did this on my RIP GLK since delivery and never had a bad smell even once.

The cavities of the body of the car are sprayed with a wax to aid in corrosion resistance. It is normal for this to leak out when the ambient temperatures increase. You may notice a waxy residue on some of the body panels under the hood, lift gate and rocker panels. This has been known to be a contributor to the odor inside the cabin. Have your dealer to look into this issue and verify.

Not my problem. We run in Auto Mode, whole cabin, zones off, temp at 72F, very dry climate. AC doesnt run very hard. Sounds like the fix is actually a workaround to turn off compressor a few minutes before shutting off car to dry out coils. Too bad MB cant fix this.

A/C Smell
 

I have the smell since new in 2013 this is the third time I have complained about this Mb now they have ml350 for four(4) days now, they tell me they had to order a body panel inside the dash and it is quite extensive labor to fix it, I will update this post when I get the TSB and part #s

AC SMELL\
 

TSB
LI83.30-P-059119
JUST GOT MINE BACK FRIDAY FROM DEALER SMELL GONE, WE WILL SEE FOR HOW LONG

SOLD my ML350 after 2 years
 

I finally had enough of this problem with Mercedes and sold My ML350. I cant believe such an annoying problem can persist for this long. I had a severe throat infection late last summer, which I believe originated from the smelly, rotten A/C air. I traded the ML for a brand new Lexus, which does not have an issue with the A/C.

You don't have an issue for now...I had a Lexus RX 400h before the ML350 and it had the same problem...not to mention the quality, Lexus can't (by far) be compared with the Mercedes quality...

I do not have the statistics handy for the Lexus vs Mercedes reliability but I am pretty sure Lexus has a better track record than most European car manufacturers when it comes to reliability.
I have had more gripes with the ML350 in 2 years than my previous RX in 15 years. Bottom line; Merc is not worth the extra $.

I am sure they do, but if anyone buys the Mercedes for top reliability they have not been doing their homework.

Many car manufacturers have been known for reliability over the years, such as Toyota, Honda, Lexus, and now even Kia and Hyundai are doing pretty well in that area. Other brands have been known for being more hit or miss on this point of reliability such as Jeep, Jag, Land Rover and even MB. If you get a bad one woe is you but if you get a good one you will enjoy the ride thoroughly.

Basically, it is a crap shoot with most European makers and has been the nature of the beast for many years now. Why is this so? Well, maybe they are over engineered. Maybe they have too many bells and whistles that could go wrong. Maybe their quest for coming up with the latest technologies are always a bit premature and not thoroughly tested. And just maybe their quality control is not what it use to be. Maybe this, maybe that but everyone knows it is hit or miss going in.

I doubt very seriously that most MB buyers look closely at the CR or Edmunds reliability reports. They know those MB reports can't match some of the others, such as Lexus, but they think it is worth taking the chance. I know it was for me. My test drives convinced me the ML was a better vehicle in most of the important ways that mattered to me than the RX350, and by a considerable margin. I knew it was a better car assuming I lucked out and did not get a lemon ML.

I was lucky and got a good one but I'm certainly not the only one. For every complaint we hear at this forum or at other internet places there are probably ten other owners whose cars have performed as expected, such as my car has. There are three 2012 ML 350 gas version SUVs here in the small community I live in and one 2011 and all have been virtually perfect from day one. I've heard enough horror stories at this forum since to seriously look at other makers in the future of course but I know MB still offers an outstanding product - IF you are willing to play the odds (which are overwhelmingly in your favor) that you will get a good one.

Bad odor from a/c
 

*** YES, I have a 2013 Mercedes Benz ML 350 and I get the same bad odor when I use the A/C , I have taken it in to service and they said it's a known issue , they clean it and it stopped the door temporary but the door is back again. I need to take it in to be fixed again.

bad smell resolved
 

I had the same problem in my 2012 ML. Not my 2103. My 2012 is garaged and my 2013 sits out in the hot sun and bakes dry in the heat. Garaging it allows the moisture to remain in the vents. After 5 different attempts to change the filter, spray some chemical in there, they finally solved the problem.

They installed drain plugs so any accumulated moisture will empty out and not grow mold. The parts were not MB parts. They ordered it and warrantied the install. So far so good it's be over a month now. I am in South Florida so the A/C is always on. My dealer where I got the car, Romano Motors in Syracuse , NY was very familiar with the problem even up north and told me they do the same thing. Hope this helps guys!!!!

I feel its a combo of cabin filters and bacteria build up on the AC condenser due to excessive humidity during the summer months in the south. I never have this problem in the fall or spring. What I do for a quick clean is give it shot of Lysol.

CAUTION: PROCEED AT YOUR OWN RISK
As with all mods or DIY articles, the information provided here is without warranty. I am providing the steps for your information, but beware that problems may occur and that you accept full responsibility.

1 - Review my post about changing the cabin air filters, you want to get to the external air intake and remove the filters so you can spray some Lysol into the AC condenser. You should be able to see the "squirrel cage" fan.

https://mbworld.org/forums/new-m-cla...r-filters.html

2 - Park the car in a well ventilated area. Lower all windows.
3 - Turn off AC compressor button and AC Recirculation. Turn Fan to HIGH. (if you cannot see the squirrel cage fan,you have recirc ON and your pulling air from the inside of the car, go turn recirc off)
4 - Spray about 1/4 can of Lysol into the squirrel cage area, you will see the air flow pull the Lysol down into the fan area. DO NOT put your hands or the can of Lysol into the fan area. Hold the can just outside of the opening to the fan area.
5 - STAY OUT of the interior of the car.
6 - Run the fans on HIGH for 5 minutes.
7 - Turn fans off and let sit for 10 minutes.
8 - Repeat steps 3 thru 7.
9 - (Optional) Start fans again and spray some air freshener into fan.
10 - Run fans for 10 minutes and let car fully ventilate.
11- Replace parts you took out in step #1.
11a - This is a good time to replace the cabin filters. See link in #1 above for part numbers.

Enjoy a fresh smell. I also have started to run the fans with AC off and recirc off about 1 mile from any time there will be extended parking time. This tends to keep the AC condenser dry while the car is parked so less chance of mold/bacteria growth. This is not a permanent fix, expect to repeat each summer.

BTW: I had 10,000 miles on the charcoal cabin filters and they had a bad smell to them.

Interesting thread - instead of Lysol my recommendation is Klima-Cleaner from Eiznette:

can someone please post PDF of this TSB? LI83.30-P-059119 thanks

Yes there is a funk
 

I looked far and wide for info on the web to verify that there is indeed something funky about the AC units smell. I noticed it at 4-5K miles and at 11k miles I finally spoke with a foreman at my local Benz dealership who told me that there is a technical bulletin that has a 3 to 5 hour procedure to correct the issue. I told him that I've tried to de-func the ac system by replacing the filter and spraying disinfectant. He laughed and said that would not do the trick. He rattled off drain/vent/duct/ "maintenance" that was required. I made the appointment and dropped off the car today. My service adviser referenced a Technical bulletin for the ML (vs GL), but the systems can't be vastly different. She contacted me after I dropped the car off to have me fill out a questionnaire that was required for this 5 hours to be covered via warranty. I don't buy the "It's just the way they smell" perspective. It is obviously a mold/mildew growth somewhere in the system. I've experienced the smell one in a blue moon very infrequently on a few different model cars the years but never as constant and strong as in the Benz.

can you post more info on this questionnaire and the repair procedure/docs?
thanks!

I had the same problem in my 2012 ML. Not my 2013. My 2012 is garaged and my 2013 sits out in the hot sun and bakes dry in the heat. Garaging it allows the moisture to remain in the vents. After 5 different attempts to change the filter, spray some chemical in there, they finally solved the problem.

They installed drain plugs, so any accumulated moisture will empty out and not grow mold. The parts were not MB parts. They ordered it and warrantied the install. So far so good it's been 8 months now. I am in South Florida so the A/C is always on. My dealer where I got the car, Romano Motors in Syracuse , NY was very familiar with the problem even up north and told me they do the same thing there
. Hope this helps guys!!!!

Not sure if this is the same one, but this is the one for my 2012 E350 coupe, it can't be that different

SMELL OF MOLD, DECAY OR URINE FROM VENTILATION
TECHNICAL SERVICE BULLETIN
Reference Number(s): LI83.00-P-051588 Version 2, Date of Issue: September 22, 2011
Mercedes-
Benz:
Models 169, 171, 172, 203, 204, 207, 209, 211, 212, 215, 216, 218, 219, 220, 221, 230, 245
164, 166, 251
Design Group: 83.00 General
Reason For
Change:
Clarification of remedy for vehicle models that are equipped with air circulation filtering and
biocide-coated evaporator
COMPLAINT
Smell of mold, decay or urine from ventilation.
CAUSE
Odor complaints may be due to a wide variety of causes, e.g.:
- Saturation of the filter
- Foreign matter in the interior
- Odors entering from outside
- Hardening of insulation materials
- Contamination of the evaporator due to specific ambient conditions
A moldy (foul) odor can typically occur for a short time after engine start in all vehicles with air conditioning, is
a technically inherent effect which likewise cannot be eliminated by cleaning the evaporator.
However, the latest vehicle models feature the dry-blow function that counteracts this undesirable effect.
REMEDY
Remedy a): Model series 169, 245, 203, 209, 211, 219, 215, 220, 230, 171, 164 up to A407859, 251 up to
A083326, 216 up to A012332, 221 up to A174161
The above vehicle models are not equipped with recirculated air filtering and biocide-coated evaporator. The
following sequence of steps for eliminating odors in vehicles must be strictly adhered to:
- Identification of the cause of the odor.
If an odor problem still persists after all the possible causes of odor have been ruled out:
- Remove filter inspect it and replace it if it is saturated or clogged.
NOTE: The filter is a maintenance item and is not covered by warranty!
- Cleaning of the evaporator of the air conditioning system in the installed state using "Mercedes-Benz
Contra Sept disinfectant cleaner". Further information on the cleaning procedure can be found in S-B-
83.30/134.

FIXED IT
 

I've been smelling the same thing for months....Mississippi gets HOT so I watched this, ordered on Amazon, literally started it back up and NO SMELL AT ALL. It has been 3 weeks....hopefully it is gone
This video here >>

GL 350 Moldy AC
 

Had a <2 year old diesel GL 350 with the same issue. Wanted to post our Service Bulletin#LI83.30-P-059119 that I've seen mentioned but never seen a copy of...With the possible health consequences of mold exposure we opted to get rid of the car (painful cash loss) after the work was completed since we didn't see any reason this would not be a recurring issue and our extended warranty would be up at 100,000 (I drive 30-35,000 per year)

To all of you who've had this bad smell problem and have spent money trying to fix it, or had any other monetary loss: THERE'S A CLASS ACTION LAWSUIT THAT'S BEEN FILED ABOUT THIS! I've had the same problem in my CLK 500 and now in my C Class and I'm furious that MB calls it "normal". IT'S NOT! I've spent money trying to fix it and now I can't drive clients around in my car cuz the smell is nasty (I'm a real estate agent). This is an unacceptable problem in a high-end car! Google "bad smell in Mercedes" and "Lieff Cabraser" to find the lawsuit website if you want to add your name to it.

Had it in my c class. Dealer fixed it with a cleaning of the HVAc system and replacement of filter. No further issues.

I have a 2016 GLE 350 and the smell issue has been a continuous issue. I purchased a vehicle that was a loan car and only owned by the deal. I suppose my first mistake was purchasing a car I didn't test drive, as I test drove a different GLE 350 with way more miles. First thing I notice is the smell and it has continued for a month, it has even continued 24 hours post the dealer's replacement of the filter. Is there a specific name/condition I can refer to this as for when I take it back to the dealership? The smell is pungent!

I'm also a real estate agent and took mine into my local dealer twice over this for the same reasons. Pretty piss poor to have a vehicle that is regarded as a nice vehicle and not be able to have clients in it. After my second trip with my clear dissatisfaction with the issue, my local dealer spoke with MBUSA and whatever they did, it's been gone for 6 months so far.

Bad smell
 

It is 2017 and I have the same problem. I have s400 2014 and when I start the engine the air coming form AC smell very bad, I changed the filters, put some sprays , and the problem remains.
Any idea

I like what I see in this video. I have 2013 GL450 which i think the cabin filter is located in different location (seems like it's accessed from the engine bay rather than from foot well), anyone know in that car how do I try to get the spray onto the coils?

Easier than expected...
 

So…while it is an absolute un-deniable FACT that the ML (and likely other models) has a design defect that allows for the growth of some mold or mildew in the AC system, I discovered how extremely simple it is to replace the cabin air filter and the two “fine particle” (i.e. carbon) filters by going through the engine bay; AND while doing this, simply spraying the Kool-it cleaner followed by some Lysol into the running system. We’ll see how long this lasts, but so-far there’s NO smell…and in the future, I can see myself repeating this procedure (without having to replace the filters) in less than 10 minutes, as needed. It’s so easy to remove these filters.

I also recommend trying to remember to turn off the AC compressor (pushing the AC button) approx. 5 min before the end of your trip, like others have suggested, especially if it’s the last planned trip of the day. This helps to dry-out the evaporator. I did notice that pushing the AC button OFF (so the light on the button turns off) doesn’t shut the AC compressor off under certain circumstances, usually if the interior is hot and you just started the car….it seems to still run the compressor (blow out cold air) for the first 10 minutes or so, even though I manually turned it off.

This all being said…..EVERY car has some type of design defect, or some little feature or issue that is undesirable. So, having to take 10 minutes to spray a little Lysol into the AC system every 3, 6 or however many months, is really a very minor issue. After doing this procedure, I like the car even more.

So just want to clarify what you did - so you spray the kool-it from the air inlet, with the 3 filters taken out? Did you get the kool-it liquid dripping out from the AC drain underneath the car?

I was planing to jack the car up and take the mud shield off to locate the drain tube and apply the kool-it from the drain tube (like how the kool-it instruction describe). but if it works from the air inlet, that's probably less work...

Previous i tried spraying lysol (but didn't take the filter out), didn't seem to too much. the spray probably didn't get through the filter to where the moldy is i imagine...

I would not spray anything into the system with any of the filters in place. I did only half the can of Kool-it, in little bursts, right into the spinning centrifugal ("squirrel cage") fan. (You must see the fan, or the recirculation louver may be closed, blocking-off the exterior intake, preventing you from spraying it into the fan.) I did not check under the car. I ran it for a few minutes, then I did a few short bursts of Lysol into the fan. Ran it for a few minutes more. Then re-installed all filters (I replaced them, since they were over a year old).

My FJ Cruiser has, in the past, exhibited that same putrid smell. Ever since I started shutting the a/c off a couple minutes before getting home while leaving the fan running full speed, no more smell. As Brent states, allowing the evap to dry out seems to do the trick

I think car manufacturers should program the fan to run for a few mins after the engine is off.
It won't hurt the battery but will fix the issue ;)

Someone posted a technical service bulletin somewhere in this forum about that.....supposedly, the car does run the fan, but the standard setting is to wait 3 hours before starting the blower (after engine shut down), and the service bulletin changes that program to 3 minutes.
Maybe someone can chime-in and provide more info on this?
It would be nice if we can simply bring our cars in, and have them re-program this feature......for FREE, of course!

I've owned MB's for the last 25 years and never had this problem.

We have humid summers here in Australia so assume it should happen to us.

I never run the car on re-circulation and always have outside air entering the cabin.

maybe I'm lucky or just not creating the environment to have the mould grow?

Yeah, I read through that TSB....and all that work plugging all those holes makes absolutely no sense to me. I can't imagine what that has to do with water/moisture remaining on the evaporator. I would like to hear an explanation of how that would work....
Also, the filters should have nothing to do with this issue...they are located before (i.e. upstream) of the evaporator, and likely do not retain water on them and do not promote growth of mold/mildew. When I removed my filters, I stuck my nose right up to all 3 and there was absolutely no smell and no evidence of mold/mildew on them...they were clean (I replaced them anyway, since they were over a year old). If anything….I would think all those filters could hinder any water/moisture from evaporating out of (or off) the evaporator. Seems like older cars that don’t have any cabin air filters had less issues of lingering water/moisture on evaporator coils.
The cleaning of the coils was probably made the smell go away.

You must be a service advisor for mercedes, you sound just like them!!! IDGAF who drives what, where or how they interpret the smell, the fact of the matter is that this smell is a result of a poorly designed hvac system!!!!

We're you able to get out of this problem? Currently going through same!!

Newer had this, Temp control aways in Auto, and newer in recirculation. Leaving in sunny Seattle, WA.
Dust filter changes every 10K and cabin filters every 15K.

PS. My wife's car, not MB had this once, had to turn fan full speed and used Lysol cleaner run and sprayed for about 30 mins.
Replaced cabin filter, so far so good been a year now.

Agreed, MB had design problem, but looks like its climate dependent otherwise we would see so many claims and recall.

I purchased my glc brand new off the lot, smell started at 3rd month. I live in the driest desert of all. Filters have been changed, cleaners have been sprayed, all by dealer. Smell has never gone away. My ac runs on auto, with fresh air intake on. My headliner reaks, my kids car seats reak, my mats even smell. I've had my vehicle for less than 6 months.

I purchased my glc brand new off the lot, smell started at 3rd month. I live in the driest desert of all. Filters have been changed, cleaners have been sprayed, all by dealer. Smell has never gone away. My ac runs on auto, with fresh air intake on. My headliner reaks, my kids car seats reak, my mats even smell. I've had my vehicle for less than 6 months.

So, while my service history said the dealership performed the LI83.30-P-059119, the smell still persists because that bulletin's theory is "Oxidation products of the cavity preservation can enter the interior compartment via the air conditioning". We all know that IS NOT the case....it's the mold/mildew forming on the evaporator.
Therefore, I just stopped into the dealership to inquite about them performing service bulletin LI00.00-P-066047 (which includes re-programing the climate fan to come on after 3 min instead of 1 hr), and they want to charge me $660.00...just to update the climate control software.
That's outrageous!
I even have an extended warranty.
It's like Mercedes actually WANTS to lose a customer for life.

That's ridiculous. If there's a service bulletin for it, how can they justify charging you for it?
Stir ***** 'till they cave.

To be honest it could just simply be mold. Back when I was in college I had a similar issue with my Honda Accord. I took it to the dealership and they simply put my windows down, cranked the AC and the fan on full blast and sprayed lysol from the outside near the wipers where the air goes into the AC unit. It surprisingly got rid of the smell. With that said, try doing the same with your car. I still do it to my other cars every now and then. Just remember to keep ur windows down for a maybe 10 minutes and have the AC and fan on full blast after you spray the lysol that way the chemical smell leaves ur ventilation system and ur cabin. Hope this helps, keep us posted.

It absolutely IS mold…..there’s no question about it. The service bulletins that have them take apart your whole interior and plug-up and seal various holes in the body, do absolutely nothing. It’s simply mold growth on the evaporator.
And I highly recommend removing all the filters, before spraying any cleaner into the system.

Has anyone had the dealership re-program their climate fan (to turn on after 3min in lieu of the default 1hr)? Does anyone know how much they should charge for that service?

So, after reading the extended Certified Pre-owned Limited Warranty...
It states the following is covered under electrical items:
"....sending units,sensors,switches,fuse boxes,relay modules,control modules,transmitters,instrument panel,gauges,rheostats,potentiometers,blower motor series...."

Therefore, wouldn't the procedure of "Updating the latest software for the air conditioning control unit" (from bulletin LI00.00-P-066047), including changing the values for the drying time of the evaporator be covered under the "control modules" part of the warranty?
And under the Climate Control section, it states: "All electrical components noted above,as well as the A/C compressor and clutch,receiver/drier bottle,refrigerant hoses and connections,evaporator,expansion valve,condenser,rear vent control cables,vacuum actuators,all vacuum valves and elements,auxiliary cooling pump,cold engine lock-out switch,temperature selector wheel,servo unit,monovalve,dualvalve,switch over valve,heater core and heater housing assembly.

Unfortunately...I think I'm going to have to fight this. I guess I'll call the 1-800-367-6372 number.