Performance Air Filters Bad?

//Tim\\ · 08-29-2011, 03:29 PM

I was browsing a BMW Service blog and ran across the article below. It seems to make sense. Thoughts from those who've used different filters?

La Jolla Blog

mlifxs · 08-29-2011, 04:03 PM

I have a K&N drop in for about 10k miles. Cost $40.
After install, the car felt slightly better. Seemed like it pulled a little better at lower rpms.
Also, I noticed a solid increase in highway mpg, around 1-1.5 mpg (according to the computer).
Now, part of this could be because the paper filter needing cleaning / replacing. It wasn't terrible but it wasn't brand-new either.

I have read that folks sometimes "over-oil" their filters when they maintain them and there is a risk of soiling the MAF sensor.

Dr. Nate · 08-29-2011, 05:53 PM

Most people fail to clean or oil a reusable filter properly.

-Nate

mlifxs · 08-29-2011, 09:16 PM

I wonder what the BMW Performance Intake filter is made of? In this DIY http://www.e90post.com/forums/showthread.php?t=195658 it looks very similar to a K&N

MaximusJ · 08-29-2011, 09:31 PM

This intake use another kind of paper filter. It uses a different airpath also.

Sealed box intakes are worth it; open air ones arent.

I've slammed a K&N into my PI since day one and I sincerly felt that the car now breathe better. I've had a K&N/Charcoal delete setup before and before that the aFe. And trust me the PI is worth every penny. Refined intake sound and no heat soak FTW!

But I must say I agree that oiling a filter properly is a crucial thing to do to keep your MAF clean.

tolkino · 08-30-2011, 01:04 PM

Quote:

Originally Posted by mlifxs

I wonder what the BMW Performance Intake filter is made of? In this DIY http://www.e90post.com/forums/showthread.php?t=195658 it looks very similar to a K&N

BMW PI uses a K&N filter.

e90pilot · 08-30-2011, 01:11 PM

The E90 has a cleaning cycle on the MAF. Older BMWs like the M5 did not and had many issues with it. The M5 had ate MAFs stock. With oiled filters it was worse. Also, K&N filters come WAY to oiled from the factory. Let it sit in the sun for a bit. Mine was dripping when I got it. Some say let it dry out completely and re-oil it with the kit. The instructions call for only a few drops.

benzo23 · 08-30-2011, 01:41 PM

Yea i noticed that with my k&n too when it was new, i took a paper towel and soaked some up...i did the charcoal delete and i have to pick my car up from the dealer here in a cpl hrs i think im just going to pick up another oem filter, the k&n hasn't been in the car in weeks because it was black and im to lazy to clean it. So i stuck the old dirty paper filter in the mean time.

08-29-2011, 03:29 PM	#1
//Tim\\ New Member $//Tim\\'s Avatar$ 1 Rep 22 Posts Drives: 2011 AW 328i E90 Join Date: Aug 2011 Location: Louisville, KY iTrader: (0)	Performance Air Filters Bad? I was browsing a BMW Service blog and ran across the article below. It seems to make sense. Thoughts from those who've used different filters? La Jolla Blog __________________ 2011 E90 328i \| Alpine White \| Black \| Glacier Aluminum ZMP \| ZPP \| ZCV \| ZCW \| ZVP \| NAV
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08-29-2011, 04:03 PM	#2
mlifxs Diamond Geezer 212 Rep 2,385 Posts Drives: Jet Black 2007 328i Saloon Join Date: Nov 2007 Location: Florida iTrader: (6) Garage List 2016 VW Golf Sportw ... [10.00]	I have a K&N drop in for about 10k miles. Cost $40. After install, the car felt slightly better. Seemed like it pulled a little better at lower rpms. Also, I noticed a solid increase in highway mpg, around 1-1.5 mpg (according to the computer). Now, part of this could be because the paper filter needing cleaning / replacing. It wasn't terrible but it wasn't brand-new either. I have read that folks sometimes "over-oil" their filters when they maintain them and there is a risk of soiling the MAF sensor.
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08-29-2011, 05:53 PM	#3
Dr. Nate Nate Dogg 8 Rep 437 Posts Drives: 2011 328i Saloon Join Date: Apr 2011 Location: Houston, Texas iTrader: (0)	Most people fail to clean or oil a reusable filter properly. -Nate __________________ 2011 BMW 328i by weekend, various airplanes by week.
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08-29-2011, 09:16 PM	#4
mlifxs Diamond Geezer 212 Rep 2,385 Posts Drives: Jet Black 2007 328i Saloon Join Date: Nov 2007 Location: Florida iTrader: (6) Garage List 2016 VW Golf Sportw ... [10.00]	I wonder what the BMW Performance Intake filter is made of? In this DIY http://www.e90post.com/forums/showthread.php?t=195658 it looks very similar to a K&N
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08-29-2011, 09:31 PM	#5
MaximusJ Colonel 303 Rep 2,485 Posts Drives: 340Xi MG 2017 Join Date: Jul 2010 Location: Quebec, Canada iTrader: (21) Garage List 2017 BMW 340XI (F30) [9.00] 2006 BMW 325I (E90) [7.44]	This intake use another kind of paper filter. It uses a different airpath also. Sealed box intakes are worth it; open air ones arent. I've slammed a K&N into my PI since day one and I sincerly felt that the car now breathe better. I've had a K&N/Charcoal delete setup before and before that the aFe. And trust me the PI is worth every penny. Refined intake sound and no heat soak FTW! But I must say I agree that oiling a filter properly is a crucial thing to do to keep your MAF clean. __________________ Mineral Grey '17 F30 340XI [Garage] // [Build Journal] Jet Black '06 E90 325I [Garage] Last edited by MaximusJ; 08-29-2011 at 10:32 PM..
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08-30-2011, 01:11 PM	#7
e90pilot Freight Dawg 104 Rep 2,103 Posts Drives: E90 325i Join Date: Jul 2005 Location: Oakland, CA iTrader: (3)	The E90 has a cleaning cycle on the MAF. Older BMWs like the M5 did not and had many issues with it. The M5 had ate MAFs stock. With oiled filters it was worse. Also, K&N filters come WAY to oiled from the factory. Let it sit in the sun for a bit. Mine was dripping when I got it. Some say let it dry out completely and re-oil it with the kit. The instructions call for only a few drops. __________________ --Marcelo '06 Arctic Metallic 325i \| Sport Package \| 6MT \| Dinan Stage III suspension \| Dinan exhaust \| 330i manifold swap! Click here! \| Active Autowerke tune \| 135i Brake Calipers \| Deiselboost caliper brackets \| E46 M3 front rotors
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08-30-2011, 01:41 PM	#8
benzo23 Colonel 74 Rep 2,848 Posts Drives: 14 F30 AW MSport Join Date: Apr 2010 Location: FL iTrader: (1)	Yea i noticed that with my k&n too when it was new, i took a paper towel and soaked some up...i did the charcoal delete and i have to pick my car up from the dealer here in a cpl hrs i think im just going to pick up another oem filter, the k&n hasn't been in the car in weeks because it was black and im to lazy to clean it. So i stuck the old dirty paper filter in the mean time.
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