Been researching changing cabin air filter and my recently purchased 2017 C63 Sedan has 20,000 miles and not sure IF this has been done. I assume it’s the original cabin filter. It was a Genuine Mercedes Filter Item Stamped on Filter # A205 835 00 47. I initially had several questions, but I answered them myself while I was doing everything as nobody responded in time.

Took me 5 minutes and I had the current cabin filter out. Took 2 screws off under glovebox L&R (I think I was missing 1 in the center), pulled down on piece that was held on my screws, twisted 1/2 turn to remove temp sensor, and released light bulb connector to unplug the light bulb. Once these 2 are removed/unplugged, the piece comes out, just pull DOWNWARD!

Bought a Mann Filter that said it fit my car but it doesn’t. However, after more time working on things, the Filter I had was for my car, but it wasn't for the Cabin AF, it was for the FILTER Under the HOOD, on Passenger Side, under the black cowl.

I’ll show a picture of my car with the underhood filter removed, with that removed, you to see a FAN that looks as if it draws air from under the hood. I also bought a KOOL-IT Evap. Cleaner Kit on Amazon. I didn't know where the evaporator was located, but I stuck my phone inside the Cabin Air-Filter Opening I removed and barely held my iPhone with tips of fingers (my whole hand wouldn’t fit) and pointed the phone toward the Left, toward radio and saw a WHITE Plastic Filter looking thing, which I think is the evaporator, I will post a picture from my phone.






I forgot how I took out Cabin AF, but from the diagram below, it looks like the slanted cut off piece is located on the Top Right when it's reinserted. I took a Sharpie and marked the Arrow directly on the filter (where there was a faint arrow shown) just so you all could see where the arrow location is located on the Cabin Filter.




Here is Cabin Opening. the Evaporator (The White Filter I will picture Below), is up inside that somewhere to the left. I read it is about 6 inches to the left from the opening.





White Filter (Condersor/Evaporator). My phone is pointed toward the LEFT side or center of the car from up inside the cabin AF Opening.

Evaporator located up inside of Cabin Air Filter opening toward the Left!





Here is the Cabin Filter, don't UNDERSTAND the ARROW? I know it to show direction of air-flow, but it's pointing UP? How would anyone know which way the filter was supposed to be installed from that Arrow on the filter?
I didn't pay attention when I removed it, so I had to look at some diagrams to figure out how to reinstall it the correct way.

 

I never knew I had the Under the Hood Filter. I heard about it, but thought it wasn't on a W205, BUT, it's there! It's located on the passenger side under the hood, under the black plastic cowl/cover. Then you see a black rectangle plastic cover, and the filter is on the other side. Once I removed the black plastic piece holding the filter, I could now see a Fan that blows air from under the hood into the car. I thought I may be able to spray that foam there, but after looking, I decided that wasn't the place. However, this would be a good place to spray Lysol Spray with Air Fan ON to get rid of any musty smell.

Here are Pics I took below. My Engine Bay is CLEAN, but that area's plastic pieces were dusty and dirty, so I cleaned them with some Windex type cleaner.


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The fan inside cavity I mentioned above. Once black filter housing is removed from under the hood on the passanger side, you will see the FAN.

 

So there are two filters for the incoming air, one under the glove box in the cabin and one in the engine bay? Basically one on each side of the blower fan. You have part numbers for both? I’ve had my car almost a year and haven’t changed those...

 

One is for the air coming into the cabin and the other is for air already in the cabin. The one underneath is a huge pain in the *** to change (fitting it back in is finicky). The one under the hood takes 2 minutes.

I removed both, turned the blower fan on high, sprayed cleaning/neutralizing (meant for this process, not just Lysol or something toxic) into the one one under the hood. Then turn it to recirc and do the same with the intake under the glovebox. Then let it all clear out and then put your filters back in. Helps freshen things up a bit

 

Yes Boost, I Took a Picture of the Part # printed on that filter for you I figured there was a Filter because the air filter I bought online that said it FIT my car was the WRONG SIZE for my Cabin Air Filter? Way too Small! Then after I opened things up under the hood I saw a black cover that was the same size as that filter, and BAM there it was The Mercedes OEM Filter Under the Hood is Part # A 166 830 02 18 & the popular aftermarket MANN Filter from Amazon is Part # CU25002.

(I came back with a picture of MY Dirty Underhood filter and the part number stamped on side):



Underhood filter Filthy

 

OK, the next morning. I DID It!!!!! Or, I am doing it now. I was able to figure out where the Evaporator (White Filter/Screen) pictured above. It is up into the cavity of the cabin air filter (when removed) and toward the center of the car. I went on my Back with my head toward the passenger floorboard, and I was looking up into the cavity. I wedged a flashlight inside the opening so I could see. You can NOT see the White Evap. just looking up inside the cavity, I used my cell again stuffed up into there holding my the tips of my fingers to get a video of where the thing was located, so I knew exactly where it was.

I then put an old blanket in footwell, and aimed tube toward the evaporator and sprayed most of the can in there. It FOAMS a lot so watch out. Then I stuffed the old cabin air filter in there loosely just for now, to stop the foam from maybe coming out onto the floor. Waiting 15 minutes, then I am going to go and start car, put AC on LOW, probably chose Upper and Lower Circulation so it goes everywhere, then I will drive her back into the garage and replace it with the NEW Cabin AF (which I have to go to MB to go get sill today), and then the pain in the *** part (I've heard) of putting the damn lower glovebox trim back into place and reinserting the screws.

It should smell great. I replaced the underhood cabin fan filter, and cleaned that area with the fan with a few squirts of a Windex like product and wiped it down, used the KOOL-IT Foam, and will replace the cabin AF. Not much else I can do. Since I've had the car a few months ago I've done:

Replaced both engine Air Filters, what I just mentioned above, front and rear pads, oil changed, so I should be good to go. Oh yeah, and a EC Tune and an AWE Exhaust. Ha Ha

 

I should have just talked to myself in this thread.

After Kool-It Foam Was Sprayed I waited 15 minutes to let it work, then started the car and ran air on medium and set the circulation to upper and lower. I opened all my air-vents (several were closed since I don’t use them) and after running the AC for 5 minutes I looked under the car and didn’t see any liquid/water/foam underneath the car? The car smelled better but didn't drive it yet.

Now I’m on the way to Mercedes-Benz Dealership to get a cabin air filter and I am BACK. I decided to do a little extra disinfecting so I turned the AC on Recirculate so it would suck air from under the glove box and sprayed Lysol for about 20 seconds inside the empty cavity cabin filter toward the left where I basically sprayed the Kool-It Foam. I figured it would kill some additional bacteria and also smell nice.

My advice to you guys is don't be Afraid to TRY to do some of your own maintenance and things like this. People make some things out to be harder than it ends up being for you sometimes. Example, within 5 minutes of me starting removing the glove box trim piece, unplugging the temp sensor and glovebox light, I had the Cabin Air Filter in my hand, it was easy! Spent most of the time trying to figure out where to spray that damn KOOL-IT Foam. One thing that makes me feel better when I’m working on my expensive car, is the fact that if I really ever screw something up, I can always go to the dealer (or whoever you go to) and get someone to fix your screw ups, so I figure that’s the worst thing that’s going to happen and it's going to cost me some cash

Just left DEALER, $69.00 for Cabin Air Filter - 10% MBCA discount was $58.65. I read replacing the lower GloveBox Trim was a total B$%^& and wasn't looking forward to it. I also had to figure out which way the cabin replacement filter went backin? There is an arrow but to ME it was useless! I understand it is for air flow direction, but whatever way you pit it, it doesn't match up to how the air is flowing. I watched videos and looked at pictures and figured out the Slanted Cut Off Piece is positioned at the Top Right and I put the new filter in, put the bottom cover on, and locked it in place by sliding the cover.

Next, then the DREADED GloveBox Trim. I used a flashlight and LOOKED until I found the SLIT that the Platic HOOK Piece goes in. It was tricky, but I just worked at it and eventually everything just locked in place. It literally took me under 5 minutes (I got lucky) and it was locked in place. So I was HAPPY . Sure it wasn't a BREEZE and I spent hours messing with EVERYTHING. However, most of that time was me figuring things out, not actually working on anything. I did do quite a bit as I swapped both Filters, cleaned all the plastic under the hood, cleaned condenser with the Kool-It Foam Kit, also did Lysol, into the fan. I felt Good doing it Myself.

Once I actually attempted to put the new Cabin Filter back in though, it took 10 minutes. I bet I could do the entire swap from start to finish in 20 minutes. I will say in closing I have no desire to do this again anytime soon

The Bandit............

 

Did the kool-it foam work for you? I am in Houston and my car just recently developed the funky ac smell when I first turn on the ac. I watched this youtube video and sprayed 4 cans of FJC evaporator cleaner and still could not get rid of the smell.


I was not able to completely remove the panel under the glove box. There are 2 cables connected to the panel and I can't figure out how to remove the connector because I can't see it clearly. Do you need to twist and pull or just pull?

 

Sorry for digging this thread up but I need some help. I forgot to look at the air flow direction when I took out the filter from the engine bay. Is air being sucked into the cabin from the engine bay? That's my assumption but wanted to be sure. Thanks!