Removing permanent charcoal air filter

Has anyone done this? I found a discussion on the 5 series forums, but theirs seems to be glued in. Is the 3 series also glued, or is it part of the assembly?

Originally Posted by ptrcd003

Has anyone done this? I found a discussion on the 5 series forums, but theirs seems to be glued in. Is the 3 series also glued, or is it part of the assembly?

Assuming you're talking about the cabin air filter, it's a simple 10 minute task.

6 screws hold the cover and filter to the base. Remove the screws, pop the cover off, pop the microfilter out, put a new one in, screw it back down.

Pay attention to the orientation of the filter as it comes out. It only goes back in 1 way, but there's 4 ways you can position it (1 correct, 3 wrong) if you're not paying attention.

Originally Posted by Zooks527

Assuming you're talking about the cabin air filter, it's a simple 10 minute task.

6 screws hold the cover and filter to the base. Remove the screws, pop the cover off, pop the microfilter out, put a new one in, screw it back down.

Pay attention to the orientation of the filter as it comes out. It only goes back in 1 way, but there's 4 ways you can position it (1 correct, 3 wrong) if you're not paying attention.

No, I'm talking about the permanent filter built into the intake. It sits adjacent to the replaceable engine intake filter.

This one on the left:

no we don't have one.

Originally Posted by ptrcd003

No, I'm talking about the permanent filter built into the intake. It sits adjacent to the replaceable engine intake filter.

It's not glued in on the E60, but secured by clips albeit extremely tough clips. They're removable, and a few people did even though it says do not remove on it. There's a bit of a deeper sound on WOT and a 1-2 MPG increase at best.

Originally Posted by Leekay07

no we don't have one.

I'm looking at it as we speak.

Originally Posted by ptrcd003

I'm looking at it as we speak.

If you indeed have one you can choose to remove it by prying a flat tip screwdriver between it and the side of the air box itself. Pry the corners and work around, it should pop out.
Absolutely nothing wrong running without it. I've had mine removed over a year now, and coupled with an RPI scoop and K&N filter. The sound is noticeably different under load.

EDIT: The increase in MPG was due to the fact that I did a bunch of maintenance on my car at the same time, (coils, plugs, belts, hoses, coolant, oil...) so the MPG may or may not change

Just tried, and it seems like the filter is built into the air box? I do not see a seam, and the plastic around it actually cracked when I tried to try it apart with a screwdriver.

It's not built into the airbox on the E60, and im sure it is not on the E90.
Here's mines removed:
http://www.bimmerfest.com/forums/alb...ictureid=26627

My best recollection of how most people remove it is by cutting it out.

The issue is the part number could not be found on that filter at all so it could be replaced. If you needed to order it, you would have to order the whole intake silencer which is ridiculous.
It's held together by clips on the E60. I can't imagine it being part of the box on the e90.
It's not listed here:
http://www.realoem.com/bmw/showparts...48&hg=13&fg=20

Originally Posted by tturedraider

My best recollection of how most people remove it is by cutting it out.

Seems to be the case with the E90 as crazy as that is.

http://www.e90post.com/forums/showthread.php?t=21590

Just make sure that when removing something like that, you can put it back together if needed. Cutting it out might result in a lot of work if you have to return it to stock. Neatness counts.

Finally got it out. Cut the filter, then used a dremel with a sanding bit to clean up the edges. If, for whatever reason, I need to replace it, I can pick up an entire silencer box from a junkyard for around $50. If anyone plans to do this, make sure you soak the filter first to avoid dust.

Really doesn't seem to make sense to cut it out in a 328, the only difference that can be felt is if you use a less restrictive (and less filtering) K&N filter instead of the OEM, even then effects have been minimal. But if you already did it, make sure there are no lose particles anywhere that could get sucked into the engine

i removed mine, it was glued on, just cut it out with a blade. heard it was a emmissions thing when you turn off the car, it doesn't spit carbon out into the air backwars or soemthing. i donno

i also added a k&n filter. on my 330i, it was more free revving, especially at higher rpms when the final stage of the intake opens up. so far, over 10k and no issues. all running perfectly well.

Originally Posted by Cultr

Really doesn't seem to make sense to cut it out in a 328

It also doesn't make any sense to do it on a 335i. Any benefits perceived from doing so are entirely placebo.

From a weightlifting perspective, removing the carbon filter is the equivalent of taking tribulus.

While we are on the subject of K/N filters, is it really worth adding this over the OEM filter? I read somewhere you should not attempt to clean it, but instead just replace the entire filter with a new one.

Originally Posted by E90raw

While we are on the subject of K/N filters, is it really worth adding this over the OEM filter? I read somewhere you should not attempt to clean it, but instead just replace the entire filter with a new one.

for me, it made a big difference while shifting gears, just in town drive-ability got alot better. i do think the power band is more even all the way to redline. i still had a bit of an uneven weird lag between 1k-1.8k rpm even after the k&n and charcoal removal. (off topic), i did the golf tee unplug thing a few days ago and now it feels good in traffic. i'll do plugs next maybe it will help.

i don't think k&n adds any power, just cleans up the power band and throttle response.

Originally Posted by E90raw

While we are on the subject of K/N filters, is it really worth adding this over the OEM filter? I read somewhere you should not attempt to clean it, but instead just replace the entire filter with a new one.

The issue with cleaning is usually overlubrication. One or two nice mists on the dirty side is usually enough.
They are good filters. The fact that you reuse it makes it cost effective overtime. The sound is nice too.

Originally Posted by boramkiv

The issue with cleaning is usually overlubrication. One or two nice mists on the dirty side is usually enough.
They are good filters. The fact that you reuse it makes it cost effective overtime. The sound is nice too.

They're only cost effective over a very long period of time though. The filter costs two times more than stock + the cleaning kit. Dealers change the filter every other oil change, so it would take ~4 years to break even just on the filter cost. Also a risk that you could over-oil and destroy your MAF.