Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E53) Forum
Arnott
User Name
Password
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management


Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 05-27-2011, 01:03 PM
rocksteadyX5's Avatar
Member
 
Join Date: Apr 2010
Location: GA
Posts: 171
rocksteadyX5 is on a distinguished road
Your Thoughts on the use of K&N filter?

I wanted to get some feedback on the use/issues with K&N Filters. I was doing some research on replacing my MAF and I came across people saying that K&N Filters (If using them) are one of the issue that cause the MAF to start acting up due to the oil from the filter?

Anyone can confirm or dispute this claim or offer alternative to these filters?

thx
Reply With Quote

Sponsored Links

  #2  
Old 05-27-2011, 01:40 PM
JCL's Avatar
JCL JCL is offline
Premier Member
 
Join Date: Mar 2005
Location: Vancouver, Canada
Posts: 11,853
JCL will become famous soon enoughJCL will become famous soon enough
The K&N filter uses oil on the foam to help filter. Too much oil can damage the MAF. It is well documented that it can happen. When the oil is properly applied, ie not too much, that specific problem can be avoided. Note that the filtering efficiency depends on the oil being properly applied. Also, the filter holds less dirt, ie it gets clogged more easily, so servicing needs to be done more often than with an OE filter.

The second potential problem is codes being thrown. It can happen. It is usually related to vacuum leaks.

The bigger questions in my mind are:

1) Why would you want less filtering capability? Lots of tests show that the K&N filter isn't as efficient at removing dirt. If you don't care about the filtering, just take the filter out. That is the lowest possible restriction, although it will be bad for your engine to ingest dirt.

2) Why worry about the minimal amount of restriction caused by a functioning air filter? It is completely irrelevant in terms of power production.

Some additional reading if you like. Follow the links here:

http://www.xoutpost.com/794434-post4.html

Edit: I checked the links in that post, and one is broken. Here is another link to the Duramax filter test with graphs of K&N filter efficiency compared to an OE:

Aftermarket Air Intakes/Filters - Do They Work? - Diesel Place : Chevrolet and GMC Diesel Truck Forums
__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver

2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue

Last edited by JCL; 05-27-2011 at 02:05 PM.
Reply With Quote
  #3  
Old 05-27-2011, 03:09 PM
rocksteadyX5's Avatar
Member
 
Join Date: Apr 2010
Location: GA
Posts: 171
rocksteadyX5 is on a distinguished road
Quote:
Originally Posted by JCL View Post
The K&N filter uses oil on the foam to help filter. Too much oil can damage the MAF. It is well documented that it can happen. When the oil is properly applied, ie not too much, that specific problem can be avoided. Note that the filtering efficiency depends on the oil being properly applied. Also, the filter holds less dirt, ie it gets clogged more easily, so servicing needs to be done more often than with an OE filter.

The second potential problem is codes being thrown. It can happen. It is usually related to vacuum leaks.

The bigger questions in my mind are:

1) Why would you want less filtering capability? Lots of tests show that the K&N filter isn't as efficient at removing dirt. If you don't care about the filtering, just take the filter out. That is the lowest possible restriction, although it will be bad for your engine to ingest dirt.

2) Why worry about the minimal amount of restriction caused by a functioning air filter? It is completely irrelevant in terms of power production.

Some additional reading if you like. Follow the links here:

http://www.xoutpost.com/794434-post4.html

Edit: I checked the links in that post, and one is broken. Here is another link to the Duramax filter test with graphs of K&N filter efficiency compared to an OE:

Aftermarket Air Intakes/Filters - Do They Work? - Diesel Place : Chevrolet and GMC Diesel Truck Forums
Thanks JCL....very informative feedback.
Reply With Quote
  #4  
Old 05-27-2011, 04:56 PM
Zulu95's Avatar
Member
 
Join Date: Mar 2005
Location: Show Me
Posts: 2,634
Zulu95 is on a distinguished road
I've had one fitted for 6 years without any trouble...
__________________
Sent via Telegraph Wires using my Morse Key.
2015 X5
xDrive35i MSport
2013 X5 xDrive35i
Reply With Quote
  #5  
Old 05-27-2011, 07:38 PM
sd_boxster's Avatar
Member
 
Join Date: Dec 2009
Location: San Diego
Posts: 32
sd_boxster is on a distinguished road
Note that the review link was for a diesel truck site. Diesels run at lower RPM than gasoline engines, and airflow is less crucial at lower RPM. My Boxster @ 7500RPM is sucking a lot more air than my X5 @ 5000RPM.

I don't see any reason to run a K&N filter in a diesel X5. If my X5 was gasoline, I'd check the CFM rating of the OEM filter vs. the aftermarket filter, then find out what the CFM requirements of the engine are at max RPM, and THEN decide if the K&N was worth the cash. In almost all cases, it's probably not worth it.

I run a K&N in my Corvette, but I also have a hacked airbox, free-flowing exhaust, and long-tube headers, so the motor can actually make use of the additional airflow. Switching to a different air filter without making any changes to the rest of the intake/exhaust system is, once again IMO, a waste.
Reply With Quote
  #6  
Old 05-27-2011, 08:00 PM
JCL's Avatar
JCL JCL is offline
Premier Member
 
Join Date: Mar 2005
Location: Vancouver, Canada
Posts: 11,853
JCL will become famous soon enoughJCL will become famous soon enough
Yeah, I used the diesel engine filter test because it is good comparative data. Engines are just air pumps, whether they are compression ignition or spark ignition. And those diesels have more displacement, as well as a lot of boost, resulting in high airflow requirements regardless of peak rpm. That is why the diesel truck owners spend a lot of time discussing intake modifications and filter efficiency, and conducting tests such as this one. Building on your point about exhaust flows correlating to intake flows, that is why diesel pickups have large diameter exhaust systems, because they are flowing so much.
__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver

2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue
Reply With Quote
  #7  
Old 05-27-2011, 08:51 PM
sd_boxster's Avatar
Member
 
Join Date: Dec 2009
Location: San Diego
Posts: 32
sd_boxster is on a distinguished road
Good point about the larger-displacement diesel engines... I was, of course, thinking of MY diesel, because I'm a self-centered BMW owner.

To answer the original poster's question (again, since I got carried away due to my self-centered BMW driver ego... heh) - you won't see any perceptible gain from the K&N. While a new properly oiled filter won't foul your MAF, recharging it yourself and doing it wrong often does. Spending additional money that may wind up costing you even more money - for no perceptible change except the addition of a K&N sticker - isn't worth it.

Replacing the soiled OEM filter with a new OEM filter is a good alternative.
Reply With Quote
  #8  
Old 05-27-2011, 09:35 PM
JCL's Avatar
JCL JCL is offline
Premier Member
 
Join Date: Mar 2005
Location: Vancouver, Canada
Posts: 11,853
JCL will become famous soon enoughJCL will become famous soon enough
Quote:
Originally Posted by sd_boxster View Post
To answer the original poster's question (again, since I got carried away due to my self-centered BMW driver ego... heh) - you won't see any perceptible gain from the K&N. While a new properly oiled filter won't foul your MAF, recharging it yourself and doing it wrong often does. Spending additional money that may wind up costing you even more money - for no perceptible change except the addition of a K&N sticker - isn't worth it.

Replacing the soiled OEM filter with a new OEM filter is a good alternative.
100%
__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver

2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue
Reply With Quote
  #9  
Old 05-27-2011, 10:28 PM
kmagnuss's Avatar
Member
 
Join Date: Apr 2011
Location: Sarasota, FL
Posts: 103
kmagnuss is on a distinguished road
Waste of money.

So don't waste your money.
__________________
"There are more instances of the abridgment of the freedom of the people by gradual and silent encroachments of those in power than by violent and sudden usurpations." --James Madison, speech to the Virginia Ratifying Convention, 1788 http://www.hddforums.com
Reply With Quote
  #10  
Old 05-28-2011, 06:33 PM
Christiano's Avatar
Member
 
Join Date: Apr 2011
Location: Brazil
Posts: 226
Christiano is on a distinguished road
Quote:
Originally Posted by kmagnuss View Post
Waste of money.

So don't waste your money.
. Waste of money.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On





All times are GMT -4. The time now is 09:31 AM.
vBulletin, Copyright 2024, Jelsoft Enterprises Ltd. Search Engine Friendly URLs by vBSEO 3.6.0
© 2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.