miggy Posted September 13, 2009 Report Share Posted September 13, 2009 Hi Guys. I'm from the Philippines. I have a 2003 facelift 318i N42 2.0L BMW. I took out the airfilter box top cover today and took her to the air filter shop so I could order a K&N drop in filter for the bimmer. Left the airbox cover open while I travelled so I could show the guys at the shop what kind of filter would fit my bimmer. While traveling without the cover, I noticed that I could actually hear the engine sucking in air and I liked it! Kinda a deep "vrrrooooom" when accelerating. It maybe just me but I also felt a slight increase in throttle response, and that's with the stock dirty and old air filter. I ran the whole day without the cover as the shop is still ordering the K&N filter. I'm planning to permanently leave the airbox without the cover especially when the K&N filter arrives as I hear it requires periodic maintenance. Maybe even take out the airbox completely with the k&n filter installed. I hear it makes the filter "breath" more air. Now I know I could order a true air intake kit, but that's something I'll do in the near future. For now, I just want to know the possible pros and cons of taking out the airbox completely or just without the cover as a search has led me nowhere. Thanks in advance guys! Quote Link to comment Share on other sites More sharing options...
Sam Posted September 13, 2009 Report Share Posted September 13, 2009 The point of the filter is to ensure only air goes into the mixture, without a filter you could end up with leaves etc. I really don't advise to run the car without a filter, let alone without the box! Even if its an old one, put it in until the new arrives. Quote Link to comment Share on other sites More sharing options...
miggy Posted September 13, 2009 Author Report Share Posted September 13, 2009 The point of the filter is to ensure only air goes into the mixture, without a filter you could end up with leaves etc. I really don't advise to run the car without a filter, let alone without the box! Even if its an old one, put it in until the new arrives. The filter is still there. The only thing I removed is the cover for the airbox. I know it would be stupid to run without a filter, that would certainly break the engine. So basically, the airbox and everything else is still there, just no cover. The only reason I considered this is that when I install the new k&n filter, it will require cleaning every now and then. Unlike the airbox covers of the M series engines (which I think had clips wherein you could simply remove the cover with ease), the N42 engine is a pain! You have to remove quite a number of things, namely the the cover with the bmw logo on it, the engine acoustics cover over the manifold, the MAF sensor and it's boot and etc., before you can remove the airbox top cover. I will certainly not run the engine without a filter, but I think it will do just fine without the airbox cover unless I'm really wrong. Thanks! Quote Link to comment Share on other sites More sharing options...
DJ Syxx Posted September 13, 2009 Report Share Posted September 13, 2009 This is not really making sense, so you got an air filter but your running it without the airbox so is it an induction kit you have on? I wouldn't recommend having it that way and have an open filter as you will lose power due to the high temperature you have under the bonnet. Have you got a pic of the engine bay so we know what your on about? Quote Link to comment Share on other sites More sharing options...
miggy Posted September 13, 2009 Author Report Share Posted September 13, 2009 This is not really making sense, so you got an air filter but your running it without the airbox so is it an induction kit you have on? I wouldn't recommend having it that way and have an open filter as you will lose power due to the high temperature you have under the bonnet. Have you got a pic of the engine bay so we know what your on about? Sorry sir, lost my slr lenses so I have no pic for now. Here is a pic from RealOEM of what I'm trying to ask. The encircled part is the airbox. The blue colored part of the airbox is the cover which I removed. So everything else is still there except the cover. I read somewhere that the cover mainly serves to drown out the sucking sound when you accelerate. I'm not an expert so insight and advice is always welcome. Sorry for the confusion. I titled it "running without an airbox" instead of "running without an airbox cover". My apologies. Quote Link to comment Share on other sites More sharing options...
320ci-m3 Russell Posted September 13, 2009 Report Share Posted September 13, 2009 i understand ! yes im sure it will be fine ! only problem i see is that the top cover secures the filter in place ! and seals it so that no dirt can come through. so maybe make a surround to screw down to secure it and seal it yea ? Quote Link to comment Share on other sites More sharing options...
miggy Posted September 13, 2009 Author Report Share Posted September 13, 2009 i understand ! yes im sure it will be fine ! only problem i see is that the top cover secures the filter in place ! and seals it so that no dirt can come through. so maybe make a surround to screw down to secure it and seal it yea ? Quote Link to comment Share on other sites More sharing options...
DJ Syxx Posted September 13, 2009 Report Share Posted September 13, 2009 Not really advisable as said you'll get heat going into it, effectively its like an open cone induction kit as you mentioned you noticed a growl noise well thats because of the airbox not being in place as that cushions all the noise out! If it were me I'd put the top of the box back on when you get the new filter in. Quote Link to comment Share on other sites More sharing options...
duffman Posted September 13, 2009 Report Share Posted September 13, 2009 dont do it mate Quote Link to comment Share on other sites More sharing options...
MattBMW Posted September 13, 2009 Report Share Posted September 13, 2009 hello pare, just like everyone has said hot air is gonna cause you problems as it reduces the engine performance...thing is it's gonna be hot and dusty there in the philippines anyway so I would keep the standard closed airbox....if you want uprate the filter get a drop in one like a K&N which fits inside the standard airbox Quote Link to comment Share on other sites More sharing options...
miggy Posted September 14, 2009 Author Report Share Posted September 14, 2009 Ok guys. Thanks for the sound advice! Got a long way before I really get good on understanding cars as I am just starting to tinker with it. Thanks! @MattBMW You're from the Phils matt? Quote Link to comment Share on other sites More sharing options...