Black foam in the bottom of the air filter housing.

[fpb111]

Folks,

Does anyone know the part number for the black foam in the bottom section of a 2003 C2 air filter housing? I was vacuuming the dirt out during a filter change and some of the foam came with it. Almost like the foam that covers the air diverter flaps in the HVAC box.

[dan189]

I have wondered what that foam is for, the dealership didnt know when I asked them. Unfortunately you cant buy individual parts for the airbox only a new unit as a whole I did search awhile back and another member asked the same question but no one knew what it was for 

[britdave]

I found this in mine years ago, and I believe I was advised to get rid of it, and NOT to replace it ? It wasn't necessary. 

[JTT]

I pretty much got the same advise as Dave.  Doesn't seem to do anything other than perhaps act as a sound damper.  I replaced mine with an old bit of filter foam I had around cut roughly to shape, but I don't think it was necessary.

[fpb111]

So general conscensus is not needed? It does not appear to be filtering anything. Wonder if it is to dampen resonant frequency at certain RPM? Or maybe soak up water and release it slowly it has an undulating knobby surface. I will probably go JTTs direction and just cut one from some filter foam if something like it is not available. Wonder if VW or Audi uses it?

[Ahsai]

My guess is also sound dampening.