sharkey_lsu

So I changed my engine air filters yesterday with 2 MANN filters and I noticed there are what appear to be secondary air filters (white accordion style and seemed permanent) that the new filters basically touch. I assumed these are normal until I watched a video of air filter change for a c class and there were no secondary filters just empty plastic behind the filters. Can anyone verify that they have the same setup and if so, do we never have to change them? My car is a 2009 c350 BTW.

AkaSigFreak

Please update your profile to show where you are located- it helps others help you.
It sounds like the Charcoal Filters C63 owners refer to.

Pete7874

Mann catalog only shows one type of engine air filter for your car -C 3698/3-2. Your car requires two of these.

Not sure what other filters you are noticing. Maybe take a picture and post it here.

The other filter is the cabin HVAC filter, but that one sits under the glove box inside the car, if I'm not mistaken.

sharkey_lsu

Here are images that show what in referring to. They appear to be oem and there also appears to be no way to change them. I'm guessing they are permanent and the fact that they come after the air filter keeps them clean. Just seems like something that would eventually need to be changed.

Pete7874

That's weird. I don't remember seeing these when I was changing the air filters on our C300.

tiyyara

DO not have that either
08 c 300 luxury 4 matic

Do you have a flex fuel engine?

erkan kosar

i have that on my 2010 c300 sport idk what its is

acr2001

I've seen them on other vehicles. They are carbon filters, required under some environmental regulation or other, probably to prevent any retrograde circulation of exhaust or fuel vapor into the atmosphere. You can probably just rip them out and gain a tiny bit of power. Not 100% sure though, because these do look a bit different from the ones I've seen.

edgalang

I have the same issue but with M276 engine. Can I just rip them out?

https://mbworld.org/forums/c-class-w...-filter-s.html

SaphGreyC63

Charcoal filters.

Many of the C63 owners rip them out, helps the engine breathe a little easier. Be careful though, no one sells just those and if you damage them you have to buy the entire new filter from mercedes.