F18BEN

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!!!!

shagin wagon

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.

fabbrisd1

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

nauticalx

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

Patch123

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.

nauticalx

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

F18BEN

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!!!!

oppjopp

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.

tyedensford

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 >>

kandc88

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)

ackattack

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.

dieseldoc

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

A31

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!

NickW

I'm also a real estate agent and took mine into my local dealer twice over this for the same reasons. Pretty **** 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.

alrugaib

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

byroncheung

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?

Brent S

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.

byroncheung

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...

Brent S

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).

peter2772000

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

DanD.

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

Brent S

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!

Rainers

Zuffen

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?

Brent S

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.