When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm sure this has been discussed a million times and I'm fairly new to the forum, I've searched some and honestly not finding much.
In the last couple weeks my wife says the AC smells awful, I drove it today and it's horrendous.
We have a 2014 E350.
We did receive some class action lawsuit legal notice in the mail some time ago but never thought anything about it..
What can we do?
Any information is greatly appreciated.
Option 1: go to the dealer and they will replace the cabin filters and likely spray a disinfectant/deodorizer through the system. Then charge you dealer rate.
Option 2: get your own MB filters and do it yourself for a fraction of the cost the dealer charges.
FWIW, I went with option 1 because I "thought" the class-action lawsuit would cover the cost entirely. Read the website: it covers a percentage of the cost (I think it was 75%, but can't remember exactly). When I weighed it up, I could have done it myself for less money than the dealer despite the suit ...and I have to wait until after November for the official settlement. And I have to trust that I'll eventually get the money.
So your call. The easiest thing to do right away is simply get the filters and see/smell what happens, maybe that's all you need, maybe not, but at least it's cheap and immediate.
It is unlikely that your smell is in the filter. The fan pushes air through the filter and then through the AC evaporator, so the filter does not remove smell from a moldy/mildewy evaporator. Changing the filter cannot remove smells coming from the evaporator. You likely need to clean and disinfect the evaporator. Either take it to the dealer or you can do it yourself. It isn’t terribly hard but it’s a messy and unpleasant job working in a tight space. If you want to do it yourself let me know and I can give you more info.
It is unlikely that your smell is in the filter. The fan pushes air through the filter and then through the AC evaporator, so the filter does not remove smell from a moldy/mildewy evaporator. Changing the filter cannot remove smells coming from the evaporator. You likely need to clean and disinfect the evaporator. Either take it to the dealer or you can do it yourself. It isn’t terribly hard but it’s a messy and unpleasant job working in a tight space. If you want to do it yourself let me know and I can give you more info.
I did mine myself, not too hard, I also changed to the yellow microbial filter replacement, don't know if this helped at all, but it hasn't come back, I got in the habit of turning off the AC button but leaving the fan on about 2-3 miles from my house, don't know if that works either, but no smells anymore.
I did mine myself, not too hard, I also changed to the yellow microbial filter replacement, don't know if this helped at all, but it hasn't come back, I got in the habit of turning off the AC button but leaving the fan on about 2-3 miles from my house, don't know if that works either, but no smells anymore.
I couldn't tell you what the dealer did when I brought ours in (post #2), but I seriously doubt they went in there and cleaned up the evap ...but who knows for sure. The invoice said filters and disinfectant/deodorizer is all. Though just a guess, mind you, if mildew forms on the filter --a soft, highly porous fabric of course-- then replacing the filter can easily be a piece of the smelly pie. Yes, it's post-evap, but since none of us knows for certain where the moisture is collecting, then it's really anyone's best guess until someone reports where they've found actual mold. So please, someone fess up with a genuine find post hvac surgery! I'm simply reporting what work was performed, and that it did, in fact, address the issue immediately, and these 3 months later all is still good. Take it fwiw.
Turning off the compressor and leaving the cabin fan blowing for the last few minutes of one's drive has long been spoken of as a preventative measure of mildew collecting, or so I've heard over the years. Again, fwiw, I've done so in our family's several other cars over the years and it has, as it seems, kept mildew smell from occurring. That we did not do so in our e350 really is due to the idea that "it's a benz, they've figured this out" thinking ...after all, this was our first MB, you know, the best or nothing? Um, yeah, right. Suffice it to say, I'm back in the habit if killing the ac and lettin that fan blow for a while before pulling in. Anecdotal, to be sure, but it has worked over every one of our cars in the past, so I'm a stickin to it.
Edward
Last edited by Edward993; Sep 26, 2020 at 12:42 PM.
I have not had this issue with either of my W212 cars. I remember that Mercedes programmed the blower motor to come on for a designated length of time after you shut the car off on my W211 to dry out the evaporator. Weird walking into the garage and all of a sudden the blower motor starts running. I don't know why Mercedes removed that program from these newer cars.
This is not a filtration issue. Supersonic and spacecraft grade filters do not solve it.
The issue is mold and/or mildew in the evaporator caused by Mercedes’ faulty design allowing moisture buildup and resulting contamination.
Partial remedy is to spray goop into the evaporator.
I agree, my 12 came with a white paper filter, my 13 came with a grey charcoal impregnated filter, surprisingly, I never had a problem in the 12. yes, I have changed it to the yellow filter. when I took out the 13 filter, there were some mold spots, but I got a can of stuff from my buddy with the HVAC company, sprayed the whole can in under the hood and up through the filter cavity.let it dry out and no issues since. I don't drive very far any more, the 12 is 8 miles away from 30K and I live in the north, so AC only three months a year. you should have seen the black stuff coming out under the dash when I cleaned the 13, wow. since I cleaned it and put in the microbial yellow filter and turned off the AC before getting home, no issues in three years. {Yet}
I did mine myself, not too hard, I also changed to the yellow microbial filter replacement, don't know if this helped at all, but it hasn't come back, I got in the habit of turning off the AC button but leaving the fan on about 2-3 miles from my house, don't know if that works either, but no smells anymore.
What product did you use to clean the evaporator?
I just cleaned mine last week using a Toyota/Subaru AC refresh kit consisting of one can of foaming evaporator cleaner and one small can of antifungal/deodorizer spray. I’d used this kit before on my VW and liked it. The foaming cleaner worked well on the MB but the smell from the second spray lasted way too long, I won’t be using it again on this car.
I couldn't tell you what the dealer did when I brought ours in (post #2), but I seriously doubt they went in there and cleaned up the evap ...but who knows for sure. The invoice said filters and disinfectant/deodorizer is all. Though just a guess, mind you, if mildew forms on the filter --a soft, highly porous fabric of course-- then replacing the filter can easily be a piece of the smelly pie. Yes, it's post-evap, but since none of us knows for certain where the moisture is collecting, then it's really anyone's best guess until someone reports where they've found actual mold. So please, someone fess up with a genuine find post hvac surgery! I'm simply reporting what work was performed, and that it did, in fact, address the issue immediately, and these 3 months later all is still good. Take it fwiw.
Turning off the compressor and leaving the cabin fan blowing for the last few minutes of one's drive has long been spoken of as a preventative measure of mildew collecting, or so I've heard over the years. Again, fwiw, I've done so in our family's several other cars over the years and it has, as it seems, kept mildew smell from occurring. That we did not do so in our e350 really is due to the idea that "it's a benz, they've figured this out" thinking ...after all, this was our first MB, you know, the best or nothing? Um, yeah, right. Suffice it to say, I'm back in the habit if killing the ac and lettin that fan blow for a while before pulling in. Anecdotal, to be sure, but it has worked over every one of our cars in the past, so I'm a stickin to it.
Edward
The filter is pre-evaporator. This is why it doesn’t help with smell from a moldy evaporator.
The evaporator is well known to accumulate mold. This is why MB lost the lawsuit about this issue. Of course you can have a moldy evaporator AND a moldy cabin filter too.
I used a digital borescope in the process of cleaning my evaporator and did observe yellow-brown contamination, presumed to be mold.
MB has a procedure document for cleaning the evaporator. I would post it but I’m without my laptop for a few days as it’s being repaired. I hope this is what your dealer did for you as it is the correct remedy.
I couldn't tell you what the dealer did when I brought ours in (post #2), but I seriously doubt they went in there and cleaned up the evap ...but who knows for sure. The invoice said filters and disinfectant/deodorizer is all. Though just a guess, mind you, if mildew forms on the filter --a soft, highly porous fabric of course-- then replacing the filter can easily be a piece of the smelly pie. Yes, it's post-evap, but since none of us knows for certain where the moisture is collecting, then it's really anyone's best guess until someone reports where they've found actual mold. So please, someone fess up with a genuine find post hvac surgery! I'm simply reporting what work was performed, and that it did, in fact, address the issue immediately, and these 3 months later all is still good. Take it fwiw.
Turning off the compressor and leaving the cabin fan blowing for the last few minutes of one's drive has long been spoken of as a preventative measure of mildew collecting, or so I've heard over the years. Again, fwiw, I've done so in our family's several other cars over the years and it has, as it seems, kept mildew smell from occurring. That we did not do so in our e350 really is due to the idea that "it's a benz, they've figured this out" thinking ...after all, this was our first MB, you know, the best or nothing? Um, yeah, right. Suffice it to say, I'm back in the habit if killing the ac and lettin that fan blow for a while before pulling in. Anecdotal, to be sure, but it has worked over every one of our cars in the past, so I'm a stickin to it.
Edward
No disassembly required. Multiple posts of black gunk draining out after spraying cleaning solution is proof.
I recently replaced both dust and charcoal filters on my W166 and there was no mold or mildew. I have the HVAC smell from time to time, I haven’t figured out a pattern. But it is not present on the filters.
The mold and/or mildew is generated in the HVAC unit to wit: the ducts and evaporator.
Don’t mislead yourself into thinking that changing a filter solves this. It doesn’t. Mercedes failed in the HVAC design. Similar to many engine design failures like head bolts, Bluetec diesel exhaust systems, soft camshafts, valve guides, chain tensioners, wrist pins, unsolved and repeated misfires on new engines and cylinder bore liner/coatings. Those are only the most egregious examples, there is a longer list of less severe but no less unacceptable design and manufacturing failures. Spend some time reading the V167 forum for new model launch problems. It’s shocking.
I just cleaned mine last week using a Toyota/Subaru AC refresh kit consisting of one can of foaming evaporator cleaner and one small can of antifungal/deodorizer spray. I’d used this kit before on my VW and liked it. The foaming cleaner worked well on the MB but the smell from the second spray lasted way too long, I won’t be using it again on this car.
I don't remember, white can, blue writing,LOL. smelled like oranges or citrus. Smell went away after a week or so, it was winter so the heat was on
Also, I realize the filter is pre evaporator but if less microbes come in from outside air , maybe the evaporator wouldn't grow mold so much?
Last edited by pierrejoliat; Sep 26, 2020 at 03:55 PM.
Yeah, gunky stuff coming out after cleaning, or a borescope revealing gook, sounds like proof of mold to me, for sure! And no disassembly req'd is great news, good to know for the future!
To be clear, again, I'm not "mislead" into thinking it's the filters only, nor did I suggest a simple filter swap fix it. I was simply stating what had been performed on our 2014 (with ~71k miles on it) and that we've been good now for a few months ...and in SoCal late summer swelter, we have absolutely been using the AC! I hope the dealer did an evap spray/clean etc, but who knows, really?!!
.
.
Water/condensation + contamination = unwanted result
This is the facts of life for any indoor aircond unit aka evaporator coil, even in houses or yachts or cars.
The questions we must ask ourself as user :
01. What cause the condensation or condensate water produced by the evaporator ? Temperature difference and the humidity of the indoor room or fresh air injection of outdoor ambient air if in fresh air mode.
There is nothing you can do about it, afterall this is how cooling works, temperature drop will juice water moisture out of the air.
02. What is the water condensate from an aircond evaporator? A simple H20 and a very clean one, it is basically distilled water.
Can this water condensate itself produce harmful mildew/mold? No it can't. However it is a great breeding ground.
Definition of mildew/mold : https://www.epa.gov/mold/what-differ...alled%20hyphae.
03. Now, I am sure all of you have an aircond unit at home. If it is a split type aircond, it is easy to inspect the evaporator.
On a hot humid day, run the aircond for few hours to cool your room. Turn it off once indoor temperature has achieved 5 celcius cooler than outside air. Open up the indoor unit and touch the evaporator, it is still wet.
Now open the doors and the windows of the room to introduce fresh humid outside air, give it 30 minutes and check the evaporator again, you will see it is MORE WET.
Close the door and all windows of the room. Now we have new humid and hot air in the room.
Inspect indoor unit evaporator, how many hours does it take to dry ? and including drying the condensate water drain pan of the indoor unit.
04. Now ask ourselves, what is the difference between a car interior and a room interior ?
In a proper home, usually a room interior get more fresh air when one well ventilate the rooms during daily cleaning/maintenance routine.
Now go back to No 2 and no 3.
Think hard for no 2.
For no 3, do you think our car evaporator eventually is not as wet as a room indoor unit ( evaporator ) when we open our car doors and let the fresh/humid air enter the car cabin ?
A car interior air space, say a W212 sedan, that is only maximum 3,000 liters of air probably. Open two doors for a bit, fresh/humid outside air will be introduced in the cabin in no time.
We dont want to fresh-ventilate our car interior like a room on purpose, usually not the case as we fear ambient dust into the cabin
No matter how good a design on a car indoor evaporator is, wet it must be, because HVAC works also by drying the air thru temperature difference and hence condensation will occur.
Now read again no 2. Can water itself produce mildew/mold ? No it cant.
The more humid the region the car operates in, the higher the risk of getting mold/mildew at the evaporator because it is very wet aka available food and breeding ground for mildew/mold to grow, if user does not combat this with cleaning the evaporator regularly.
User profile, his or her shoes actually and where the car is used will dictate the level of foreign matter introduced to the car interior and also from ambient air because the MB will open up fresh air flaps automatically at a preset time.
In "poor" my country W212 is considered executive cars. So it is usually home to office use and chauffeur driven.
Rarely the boss will step on dirt/soil/grass because our city is a concrete jungle. At home in the garage, it is ceramic floor. At the office, it is either concrete floor or asphalt.
The chauffeur will clean the car daily and carpet is a number 1 item to clean, usually twice daily of which the 2nd one is in the office garage after he dropped the boss.
Due to our 80% - 90% humidity all year round in day time 32 Celcius, sending a car to HVAC specialist to clean evaporator is a common thing and not a warranty matter, it is a must-do maintenance drill.
In fact freon pressure check on the aircond compressor is also part of the usual maintenance.
In my home, I paid service company with water jet spray to clean all my indoor + outdoor aircond units once per 2 months. In my resto, we do it twice a month. Our dust level is insane.
It is cheap to do above, US$10-15 per 1 unit of typical up to 2HP split aircond cleaning both the indoor and outdoor units and minimum 4 airconds units.
Here is an example of car evaporator cleaning workshop
Yes , you will pay dearly in USA for similar service, this is the good part of ownership in a "poor" country of mine. US$100 at best. However, I do not encourage the OZONE use if possible or if excessive.
I agree, probably some cars can get its evaporator dry faster than say W212.
But do you think simply because it get drier faster that evaporator won't harbor mildew/mold ?
Mildew can be found on many different surfaces. It is a thin, black, or sometimes white, growth produced by mold. Molds are simple plants belonging to the group known as fungi. Though molds are always present in the air, those that cause mildew need moisture and certain temperatures to grow. They commonly develop in humid summer weather, especially in closed houses.
So the greener the surrounding where one live, the more chance of mildew/mold as they are plants based anyway.
This I agree. I for 10 years ( 1995 to 2005 ) maintained one of my boss private island and his yachts. The island is so green with lots of trees and including coconuts.
We use to keep things in plastic containers like these at the island : https://d2xjmi1k71iy2m.cloudfront.net/dairyfarm/id/images/105/0610502_PE684962_S5.jpg
Damn, the box interior itself will sweat easy and get mold/mildew in just 2 weeks if left un-opened. On purpose I do not want to open it to save the items in it from salty sea air corossion acceleration, but mold I got
The yacht rooms and saloon is easier to maintain actually for mildew/mold prevention, as we run aircond everyday for 8 hours starting 9 AM to 5 PM, using shorepower while moored. Yachts has a full time captain and at least 1 or 2 crews, depending on size.
I get the crew to also clean the bilges dry daily and open to ventilate anchor lockers and all outdoor cabinets/storage daily, these are the wettest part of a yacht.
The same for my swimming pool, in lush green Bali villa of mine vs my Jakarta ( dust infested city ) home, maintaining a swimming pool in lush green area is not fun at all.
The amount of baby algae spores in the air in a lush green area is simply overwhelming. Anyone owning a pool will know, green water is fear no 1.
So what can we car owners do to delay or prevent the mildew/mold growth, but without regularly needing the workshop visit as per the video I linked ?
Filters change is a good practice but to tell you the truth, the way any car aircond filter cartrige is designed for its sealing method and the size of some species of mold/mildew could be also too small to trap it effectively, filter change alone is not the solution.
Once in a while, maybe once a week or once per 2 weeks, before you retire the car for few days, run it in HEAT mode. If you run long enough, a radiator coolant of say 80-85C will create hot enough air to dry your aircond evaporator.
Will say 65C worth of hot air at the evaporator itself kill mildew/mold ?.... well I hope this document is correct, above 55C will kill most of them. Page 3 https://cwc.ca/wp-content/uploads/20...lity-Mould.pdf
Tap/clean your shoes before entering the car if you are in areas with lots of dirt/soil/grass. Shoes are the king of contamination in a car.
If you have children, make sure no food particles dropped to the floor unseen and don't keep non bottled drinks overnight in a car.
Clean the carpet with simple "whack the floor" method if you think the removeable carpet is kinda dirty after daily use, if total cleaning/vacuuming is still a few days away.
Thanks S-P for the comprehensive review and good advice. Although M-B has a particular problem in the 212, It's good to know it happens in other brands pretty frequently as well.
Thanks @S-Prihadi , agree with all of the points. And the Mercedes design failure remains, because their condensation management choice is the failure point. Cracks, crevices, twist and turns of the ducting and drains are the root cause.
No disassembly required. Multiple posts of black gunk draining out after spraying cleaning solution is proof.
I recently replaced both dust and charcoal filters on my W166 and there was no mold or mildew. I have the HVAC smell from time to time, I haven’t figured out a pattern. But it is not present on the filters.
The mold and/or mildew is generated in the HVAC unit to wit: the ducts and evaporator.
Don’t mislead yourself into thinking that changing a filter solves this. It doesn’t. Mercedes failed in the HVAC design. Similar to many engine design failures like head bolts, Bluetec diesel exhaust systems, soft camshafts, valve guides, chain tensioners, wrist pins, unsolved and repeated misfires on new engines and cylinder bore liner/coatings. Those are only the most egregious examples, there is a longer list of less severe but no less unacceptable design and manufacturing failures. Spend some time reading the V167 forum for new model launch problems. It’s shocking.
Let's not transfer case failures valve seat, and assorted transmission issues.
.
.
Here is also, the aircond system double edge sword
That fresh air vent always open with engine OFF does GOOD and BAD.
First the BAD.
In a 31C or 88F ambient outside temperature , at 80% humidity , any component inside the HVAC system having 27C/81F or cooler has reached the air dew-point ... aka condensation will occur on all surfaces within the HVAC ducting system , evaporator and whatnot.
Use this calculator http://www.dpcalc.org/
If only MB does not open up that fresh air flap during engine off, it may allow a slower heating* up ( *loss of coldness perhaps is a better word ) of the car HVAC system as to not get them too wet after engine shut down.
We have doors open , that is inevitable when one gets out of the car. But I think that fresh air flap best remain shut with engine off, so that sudden temperature shock won't occur to the HVAC system.
I am sure you guys experienced this : when one wear glasses in a very hot & humid day, when we get out of the cool car interior, our glasses got fogged up outside the car...well imagine that on the HVAC system.
The GOOD.
Assuming sudden temperature shock did not occur to the HVAC system, I guess MB tried to well ventilate their HVAC system during engine OFF
Well, I feel the pain for those getting failures or problems from MB design faults.
I was unlucky enough having a locally assembled car and that adds another bonus of potential screw up/s.
Like this one : https://mbworld.org/forums/e-class-w...i-am-sure.html
This temperature difference and condensation is indeed a nightmare.
I recalled back in 2001 when I was handling a yacht for a client. Yacht was shipped on freighter from Hong Kong to Singapore and I have to sail it back under her own power to Indonesia/Jakarta.
I spent 3 months fixing her up good in Singapore as she was a 6 years old yacht by then, so there are room for BIG preventive maintenance.
Then came a nice 100+ footer yacht from New Zealand, built in New Zealand this baby.
After a month in Singapore this Kiwi designed yacht revealed a design disaster. Most of its headliner/ceilings got wet.
You see, big yachts always use chilled water HVAC, in fact Italian yachts like Ferretti as small as 55 footer uses chilled water system.
So its a cool approx 8-10 Celcius water mix with glycol 50/50 sent to indoor evaporator coils in all rooms/saloons/kitchen of the yacht. The main compressors and heat exchanger system is in the engine room.
The chilled water delivery uses plastic pipes usually and foam insulation on those pipes.
What went wrong was a simple miscalculation on the Kiwi calculated insulation thickness on those chilled water pipes.
The insulation was simply too thin for Singapore 80-90 % humidty and 31-32C ambient day time temperature and them pipes were sweating like Mike Tyson during a match
The water condensate then destroyed headliner/ceilings which usually are made from leather like suede or equivalent, if in a luxury yacht.
Total work to repair the headliner/ceilings and redo all insulation was a cool near US$1 mil. Well water is a blessing and can be a curse too.
Two cans to be safe (probably only need one, mine takes one, but did two the first time in 2017 shortly after I got my car as a CPO).
do this, and you’ll be right as rain brother. I’ve done this once a year now on all of our cars. For the W212, it’s most effective through the air filter housing. Watch what drips out on the ground, and you’ll know why it stink/stank/stunk so badly. This will foam up on the coil to dislodge the mold, and then goes to a liquid and takes the mold with it as it drains out onto the ground. Car will smell minty fresh for many months. I do mine once a year (usually right about now) and it keeps it nice and fresh.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
