New member here, bought a 2019 GLS 550 CPO on 3/9/20. This is my first Benz and I do love the car. I have put about 6000 miles on it and a couple of weeks ago I started getting a sweaty gym sock smell coming out the vents at start up. Having never had a car smell this bad, I Googled it. Low and behold there is a class action law suit concerning this very issue! I rode around with the windows down, heat on full blast, recirc mode on and off, cycled the air flow from defrost to dash to floor and back again trying to cook it out of there. The smell just kept getting stronger to the point where I had to roll the windows down at start up. No good. Made a service appointment and I just got the car back yesterday from the dealer who charged $225 for the evaporator cleaning and filter replacement. Smell is gone for now. As I understand it I will have to submit a claim to Mercedes to get reimbursed. I have researched this site and found some suggestions with how to prevent the smell from returning. Though turning the heat on the last few miles is just absurd. There are heat advisories here this week and its a dark blue car. Why not park 5 miles from your destination and walk the rest of the way in. So, here is the issue, I just bought a high end car that smells like a teenagers gym shoe. I can deal with the high maintenance costs, ridiculous tire wear, and other costs associated with owning a highly tuned over engineered machine but the smell is coming from mold or mildew in the HVAC system. Is it worth talking to Mercedes customer service or should I just eat the depreciation and unload the car at some unsuspecting GM dealer before the odor comes back?

 

This has been an ongoing problem with MB for many, many years hence the lawsuit. Make note that the settlement has no admission of guilt or a problem by MB...that means there is nothing that they can or will do to fix it. Make your decision accordingly. Typically the smell only lasts a minute or less after starting. You may want to learn how to remove the cabin filters yourself through the opening underhood and periodically spray some original scent Lysol with the blower fan running. There has been mixed success with this. I do it for my 2004 E55 (yes this is an old problem) and my 2011 ML350. It tends to mix the stink plus lysol odor for a few days then it goes away completely for a few months at best.

 

I am having the same problem, and I am tired of spending $200 every few months to make sure the smell does not appear. I'm ready to dump the vehicle and go with something else. I have a 2017 GLS 550.

 

Thanks for the replies, I was really hoping for some prescribed method to deal with it. i.e. spray the lysol, change the filters, bake at 350 with the fan on recirc for 20 mins etc...This car is like the supermodel that you caught some v.d. from. I just have a hard time believing that Mercedes has left owners hanging like this.

 

MB doesn't care about anything except selling more "units." The sooner you accept that, the better. I see it's your first Benz. Enjoy it for what it is, but forget everything you thought you knew about the brand. Those days are long gone.

 

Agree with greasemonkey. Mercedes is not a reliable, or "quality" vehicle manufacturer. Quality here is defined as a consistent and robustly performing vehicle for its entire useful life, from factory delivery to reasonably high mileage. "Performing" means it meets the stated specification and performance metrics advertised by the manufacturer, again from Day 1 until the end of its useful service life.

On to the HVAC smell.

The class action is not a recall. Repeat, not a recall.

It entitles owners of affected vehicles to either compensation for past expenses related to the smell, or to a future "treatment". The "treatment" is not a permanent corrective action or fix. It is simply a "treatment". Like a spray tan or a manicure.

 

Has anyone tried those spray cans of HVAC cleaners? Do they work?

 

I read on here somewhere that the brand MB uses is Klima Klean and you can get it on Amazon for about half of what the dealership will charge. The smell in mine is still gone. So the treatment works. I am turning the a/c off a couple of minutes before I get to my destination. It still blows cold air but you can feel a difference in the humidity level. Perhaps this will be a yearly maintenance item. I will say that half a can of Lysol sprayed into the fresh air intake fan didn't do anything other than make it smell like Lysol AND sweaty socks. I did that twice and let the filters sit out in the sun for about six hours trying to kill the smell before I took it to the dealer. Whatever they did worked. It must depend on saturation of the evaporator core which can only be done by putting a hose down one of the interior vents, which one I don't know and is that foam going to drain out of the drain hose or a crack in the duct work onto your floor mat, best case, or vehicle wiring? Best of luck.

 

I have a can of that Klima Klean stuff, problem is I can't find the tube that I"m supposed to stick it up. There's also some Youtube videos showing it being shot down the AC vents, but I'm not sure how safe that is.

 

Is the cleaning solution intended to be sprayed in via the condensate drain? This would be outside and underneath the vehicle, usually on the passenger side rearward of the front axle.

 

So I did the spray in the vent deal just to see how it would work. The vents have some curvy pathways so some wiggling was required to get it to what I thought was an "appropriate depth" whatever that is. Basically until I couldn't push it any further. Seemed to fix the issue, for now. Will see how it goes.

 

Into which vent did you insert the tube?

 

I ran it down the two center stack ones and then tried a little in each side, but don't know how well that worked.

 

I spent 5 minutes with a flashlight under the W166 today and wasn’t able to locate the evap drain. Probably the underbody shields need removed. I read one article that said the drain is directly on top of the transmission, that doesn’t sound right.

A way to test is to sit in the driveway for a while with the engine running and AC engaged. Then follow the condensate drips.

 

following

 

I just did the condenser cleaning spray into the hole by opening the passenger panel under the glove box but nothing drained out from under neath the car.... so I’m sure the drain tube is clogged...

now where to find the drain tube?

 

Ah yes, the stinky sock syndrome. It’s not exclusive to just MB either. I have a 2015 VW GTI that does it, and a 2013 Toyota Highlander that does it. The problem is the evaporator coil of the HVAC unit. It gets soaked with condensation, then when you shut the car off, it sits in the dark and warm air, which combined with the dust/dirt that has found its way into the system by natural usage - sparks the mold and mildew which is your smell. The real fix would be a UV light constantly shining on the coil that kills all of the microorganisms that create the mold/mildew. I have two in my home HVAC units (one in each shining down onto their A Coils). 20 year old house - smells like new construction because of these Honeywell lights. Until automotive manufacturers figure this out, this will always happen. Heck, I remember as a kid our 1987 Acura Legend stunk like rolling death...

How I fix it each summer in our cars? A can Or two of Kool-it through the backside of the cabin filter housing into the coil box. Sounds like the same type of stuff MB is using but different brand. Amazon for about $15 a can with a 3 foot tube. On my W212, it takes one can, fills the coil box and then dissolved through the coil fins and out the drain hose. It lasts about 12 months living here in the DC region. First time I did it (2018) was probably the first time ever for the car (2014), and the drainage was disgusting. Black, slimy, just gross. That one took two cans, but only one once a year ever since. Smells minty fresh after that and holds that clean smell for about another year.

if you do it through the center stack vent - just make sure your setting on your HVAC are set for those vents. If your setting are set to the floor vents, then it’s unlikely the solution will make it to the coil box. It’ll get blocked by the directional doors inside the piping. Make sure the setting is open to those vents. A mistake my neighbor made on his daughters 2013 VW Tiguan and caused a minty mess....

 

I had this one time in my W166 ML. Wife told me about how the A/C had a funny smell for a few seconds when starting up. I sprayed Lysol into the duct under the hood on the passenger side. That was about a month ago. No issues since.

 

For all owners and prior owners with issues of HVAC odors, MB has settled a class action lawsuit in Georgia (Case 1:17-cv-01701-AT) filed on 12/20/2019. This entitles current and prior owners compensation for repairs or maintenance expenses involving odors coming from the HVAC system.

Hope this helps
wgab

 

I thought there was recently a recall for this HVAC issue.

 

No recall. Repeat, no recall.

There is compensation available to owners of affected vehicles. Compensation is either reimbursement for past costs related to the issue, or a "treatment". The "treatment" is not a fix.

Repeat, no recall.

Repeat, no fix.

 

but.. wait! Maybe there's hope. I had my indy spray Ozium in the vents and hood airports, and Voilà! It seems to have gone away, for now at least. I'll update after a longer weekend trip, but so far, around town, nasty smell gone! Ozium available @ Target for some $5.

Cheers,
Bob

 

We have no choice and Mercedes don’t care but....Turn off AC a minute before reaching destination or it really smells bad get on Freeway (night is better) roll all windows down turn on heat to max all the way up put some music on and drive a big loop around your county moldy smell will be baked in 30 to 45 minutes no smell after, it’s gone.
Main thing is turning off AC minute before reaching destination smell will never come back. Only solution I have and it’s worked for me last 10 years.

 

I have a new 2020 GLS450. It has a “car wash” feature that you press to deactivate several automatic features. One of the things it turns off is the hvac, and you can’t turn it back on while in car wash mode. I’m guessing it has something to do with preventing excessive moisture getting pulled into the system and then molding up.

seriojsly though guys - a can of Kool-it via Amazon through the backside of your cabin air filter will clean out the moldy fins on the evap coil and freshen up the car tremendously. It gets all of the mold out of there. Costs $10 and takes about 20 minutes to do in your driveway.

 

Hello Gents,
just came from a thousand miler trip, with temperatures ranging from 21 to 70s, and happy to report back that A/C was perfect!!! Funny smell gone, please see my post/solution above. Forgot to add though, i have changed the cabinn air filters(all 3).

Cheers,
Bob