SilverMPower

Anyone have issues with moisture causing vents to smell really bad? Only happens on my C.

Rampage1929

Same here. Thinking about replacing my cabin filter.

aprince2die4

dealer will take care of that for you...no charge

Krytech

Not sure if it's the same thing but, I usually had my AC off during the winter but when I fired it up the other day I could smell a stale odor. That's when I remembered my salesperson telling me just the leave it on all the time...

Carsy

I have always turned my A/C off 5 minutes before arriving home to dry out the evaporator coil before stopping the engine hence not warm wet locations to breed bacteria. . Have never experienced a smell.
Use the "Search " facility to find more information on this problem

Bigozpete

Yep, my C220 CDI is about 16 months old and I've had the problem for about 2 months.

I'm taking it back to the dealer this weekend and see what they say. Read lots of posts on this forum about this issue which seems quite commonplace????

This is a Mercedes we are talking about!!!! Unacceptable, I have never had this from another car in 35 years of driving and I'm not about to live with it in this car.

Will post dealer response when I've taken the car in.

Glyn M Ruck

+1 Caused by bacteria breeding on the evapourator coils. They have an anti bug coating but still a problem occurs if you don't run warm air & keep the system dry. This is not confined to the W204

Egonvdv

thery should make that a standard thing after turning off the engine..
(ie ventilator continues to turn for a few mns)

Bigozpete

Thanks for the comments chaps.

However I still believe that on a vehicle of this quality and price I should not have to remember to switch on and off heaters and aircons before I stop to prevent bacteria build up.

My past BMw, Honda, VW and current Prado don't require this, why should a Merc at twice the price of some of the above?

So lets see what the dealer says - Taking it to Silver Star Doncaster (Melbourne)

c3nthusiast

4th generation Nissan Maxima's have the same problem. The fix was to run the AC or heater full blast and spray Lysol into the air intake vents. Cures it everytime.

Glyn M Ruck

Merc dealers carry a spray for this problem - you have to kill the stuff or it's a new evapourator. Smells better than Lysol. My next door neighbour's LC Prado has this problem. He did a trip to Tanzania - Serengeti & came back moaning of a stinking aircon. You just need to be unlucky and get a few spores on the evapourator coils & off it goes.

This is not confined to Benz but they do seem to suffer more than other makes. The HVAC design is too damn complex. Wait until one of the up to 10 (dependent on model) flap actuator stepper motor arms fails & you will see what I mean. Arms have been redesigned so hopefully you won't have the problem that requires most of the dash to come out.

delirium

same thing happened to me, dealer fixed it for free, but he made it sound like its my fault & said they will do it for free this one time. It was unusual because it smelled BAAAD, not the usual damp moist smell...

eminnet

My dealer used one special (German) spray to clean the AC system on my Audi A4 6-8 months ago and is still smelling clean up to now.
The Merc is still new (5 months, 5800 Km) and I avoid to smoke in.

Bigozpete

Took my C220 into the dealer. They were aware of the problem, no questions asked, booked in and done for free.

Still a faint smell, so I will see how it goes. If I'm not happy, back she goes.

len56

its actually happened to ALL my cars :P

Bigozpete

Did you get it fixed, was it successful, if so how?

Cheers

C300Sport

Making an assumption here: I have noticed that when you have the HVAC set on fresh air and turn the fan off, even at highway speeds, there is very little air flow...much less than any other can I have owned. Not that this is a flaw, but it may be the reason the W204 is bad about this?? Just seems like it would reduce the ability to evaporate the moisture to the outside of the car(when the car is turned off) and therefore setup good conditions for bacteria growth.

Devastator187

Not only my C, but my Accord has the same smell after turning off the A/C.

joshg1001

i have experienced this in all my cars, but now on my c class, since its new, i have started turning off the AC but keeping the blower on for a few minutes.

the thing about Merc cars is that the car auto closes the outside air circulation when you are not using the aircon, so you dont get fresh air unless you turn on the AC. this is not the case in other cars. i dont like this spec on Mercs

Glyn M Ruck

It's common on most cars - one live spore is all you need.

BTW - With a Star they can reprogramme to leave the vent open & let in outside air. It's certainly possible with a development Star - I think the standard one can do it.

My car had it. It's been clear for over a year now but you've got to knock it on the head as soon as you notice it.

justthinking

I noticed the same sour smell a few days ago...it's better now after I park the car outside on the drive way and turn a/c off and turn blower to max for about 5 min..
I will have my dealer clean the evapourator coils next week..
I also notice that there is very little fresh air when u turn a/c off even w/ blower at 4th or 5th level..
I guess the vent closing is the main cause..Glyn M Ruck or anyone, can you explain more about how to program and let vent be open when a/c is off??

peabers

Had the problem with another car before and now I always give the condenser an opportunity to dry before I stop the car. The smell was horrid so lesson learned. No such problems in the W204 thus far.

I also believe in cutting off the electrical consumers on my car before I stop the car. So my "shutdown" procedure starts about 5 minutes before my destination (about when I get off the highway until I get home.

delirium

I noticed the same thing regarding the fan not blowing if you are using vent & not auto. You have to change the "mode" so that the air is set to come out of the top vents then you will feel the air... its annoying!

delirium

i took my car in again this week because the stench came back. The dealer does not acknowledge this to be an issue, but they cleaned it for me again.

This is not the usual damp smell, my car's AC smelled, sour, rancid and like mildew!

delirium

Does anyone know where the evaporator coils are? Can this be cleaned as a DIY because I did a search & people do this themselves.