K & N Air filter

UK forum for general and technical discussion about the Z3 roadster
Post Reply
Roadster22i
Joined: Thu 19 Nov, 2009 22:29
Posts: 70

  Z3 roadster 2.2i
Location: Glossop

K & N Air filter

Post by Roadster22i »

Just purchased 1 for my 2.2i anyone know if there any good. the filter is tray type. car away at moment due to the snow ouch!
User avatar
Gio
Joined: Sun 26 Jul, 2009 18:07
Posts: 235

  Z3 roadster 2.2i
Location: Worcester

Post by Gio »

I haven't used one myself, but other people have stated in posts that they have had problems with damage to the MAF sensor.
Can't remember the details behind this, but you could try a forum search to find the posts.
ImageImage
User avatar
oakley6691
Joined: Tue 25 Apr, 2006 13:33
Posts: 257

  Z3 roadster 2.2i
Location: Abercrave

Post by oakley6691 »

I have the K&N panel filter on mine and had no problems (4 years), but i was told not to over oil it after a clean !!!!
Image
User avatar
aceman
Joined: Sun 01 Jun, 2008 11:16
Posts: 1479

  M roadster S50
Location: Wakefield

Post by aceman »

I have a K&N filter in mine with no problems !

The problem stems from the filters being over oiled from new which has resulted in the past oil contaminating the MAF sensor. I think K&N have addressed this issue but before you fit the filter just check that the filter is not over oily and wipe off any excess on the rubber surround. I also think there have been problems with people cleaning the filters and once again over oiling them.

Green cotton filters have a good reputation for being MAF friendly but I would check with any oil type filter that it is not over oiled.
Aceman

Arctic Silver '98 Z3M

Previously;
Bright RED '99 Z3 2.8

Rocking seats ? You need seat bushes click HERE
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

air flow

Post by Mike Fishwick »

Is it worth the trouble, and possible MAF sensor problems in the longer term?

Your original paper element is the same as that used on the M3, which with 3.2 litres and 7500 rpm draws about twice the volume of air through it than does your 2.2.

The filtration rate of any oiled fabric filter such as K&N, Jetex etc falls a lot when the initial oil coating is sucked out, which does not take very long.

Yes - the filter element on a Z3/M3 etc is very small when compared to a 140 bhp 16 valve Golf GTI etc, its size probably having been dictated by the amount of available underbonnet space rather than its airflow qualities, particularly when it becomes dirty. Our Golf TDI filter is about twice the size, but I would never dream of leaving it for much over 20,000 miles.

Most filter elements will pass air at a surprising rate - when clean - the size being selected to still permit an acceptable flow rate after what is deemed to be an aceptable amount of use in average conditions. If you want to maintain an optimum flow rate, just change it frequently.

You are better off keeping the original paper filter element, and changing it whenever it looks dirty.

Wherever K&N get their 50,000 mile serving interval from I really don't know - maybe they did their test in a hospital operating theatre!
Frank.A
Joined: Mon 20 Jul, 2009 21:15
Posts: 875

  Z3 roadster 2.8
Location: Twixt York and Hull

Post by Frank.A »

I totally agree Mike.

I actually change the air filters on our Passat and Corsa every year even though they do leass than 10k each.

They are quite mucky after this small mileage and I believe it is good policy to change oil,air and pollen filters each year.

As the air filter protects the Maf I would not consider using anything but a paper filter element.Elements are cheap,Mafs are not.

Also my boy racer days are long gone. :lol:
Image

2000 Topaz 2.8 Individual.

Youth would be more useful if it came later in life!
Post Reply