Permanent Air filter?

I went to change my air filter this morning and i noticed in the top of the air box there seems to be another permanent air filter. Whats that all about?

That is the fairly useless carbon air filter. It restricts more airflow and is redundant and useless, remove it if you can and the engine will breathe a little better

I just removed mine yesterday, you get a little more roar out of the engine bay :-)

Ok awesome, so basically it does nothing.

I will be removing that shortly.

Originally Posted by csnpsu

Ok awesome, so basically it does nothing.

I will be removing that shortly.

Well its debatable, some people say it helps keep the MAF sensor clean and problem free. If you plan on getting a K&N filer and air ram, removing it will increase airflow into the intake. Even without those extras you get more airflow into the intake. Just use a blade and cut the corners where it is attached and it will pop right out. If you want to reinstall it in the future you can.

I think the filter is just to reduce engine noise levels...

I think BMW themselves demonstrate the carbon filter's usefulness since it was not a standard item on any car in the EU, China or Canada.

If you have any kind of warranty leave it on, I will at least. If something happens and bmw tech see it missing, they will find a way to blame it on you lol.

I'll remove mine as soon as CPO runs out

AFAIK:
That is a carbon filter. It was put there to keep the EPA happy!
YES it does cause additional restriction.
The thought is that when the car is off, gas fumes can escape into the atmosphere.

It is there to cut greenhouuse gasses, thus stopping global warming in its tracks, saving the planet!!

Remove it and we will all be doomed.

Originally Posted by Slobo7x

If you have any kind of warranty leave it on, I will at least. If something happens and bmw tech see it missing, they will find a way to blame it on you lol.

I'll remove mine as soon as CPO runs out

Good point!!!

This thread will provide more information:

http://www.bimmerfest.com/forums/sho...311&highlight=

I took mine out over the weekend and will never put it back. I like the extra roar at full throttle :-)

Originally Posted by Slobo7x

If you have any kind of warranty leave it on, I will at least. If something happens and bmw tech see it missing, they will find a way to blame it on you lol.

I'll remove mine as soon as CPO runs out

LOL, dealers are clueless, even if you remove it they won't notice. I removed mine on my previous CPO and it never was a problem.