K&N Air Filter Good or Bad?

[AdrianL]

I am contemplating to whether change to K&N or stay with stock filter.
I heard from Discovery forum that K&N oil residue tends to clog up and mess up the MAS. Is this true? Should I get it or not?
Where is a good place to buy?

[hamrendan]

I have a Ram Air filter, and it uses a tripple foam media.. its pretty damn good, plus you don't have to worry about desroying it when you clean it..

Its true the the oil does tend to get in there, but when I am taking off the filter to clean it i take a Qtip and alcohol and clean the wire.. it takes 3 min and is a no brainer.. you have to clean it now and again anyway..


they have them cheap on ebay.. I have one up for sale on the classifieds link on this site..
Here is the pitch that sold me..
D

One (1) RamFX direct replacement high performance air filter that will fit the last year of the classic Range Rover and the Series 1 Discovery models. Check the application list below to confirm your model and year.
The filter, part number 10.1174, reflects leading edge filtration design that has been proven at all levels of motorsports from World Rally to Indy, and from Touring car to Baja.
It is just one of a range of high performance direct replacement Air Filters and Air Pipe kits that FXteknology is selling on eBay as part of our efforts to re-introduce RamFX products, formerly sold under the RamAir brand name, back to the performance and motorsport markets.
The Story On RamFX Filters -
The RamFX direct replacement air filter is the best dirty filter in the world. The statement sounds kind of funny, but what other air filter manufacturers do not tell you is that they base their filtration claims and air flow ratings on a brand new, prefectly clean filter.
The problem is, you really never run a brand new, prefectly clean filter on your vehicle. The minute you turn the key after swapping out the old one, the filter begins filling up with dust and dirt that starts restricting airflow.
The teknology used in a RamFX air filter was developed to deal with the fact that your vehicle spends its entire life running with a dirty air filter. It is just matter of degree, of how dirty. Our filter is made to flow more air when it has ten or twenty thousand miles on it, than a brand new filter from the competition.
But why is a RamFX filter the best , dirty or otherwise? It is our proprietary air filtration technology. We call it polymer impregnated volume media or PIVM and it is the next teknology in air filters and air induction systems.
Paper filters rely on 'surface' technology where dirt is trapped on the surface of the filter element - a bigger particle trapped by a smaller hole. Oil impregnated cotton gauze filters rely on what its originator calls 'depth loading' - oil coated fibers trap dirt throughout the depth or thickness of the cotton gauze.
But the depth of a cotton gauze filter is really no more than the thickness of a t-shirt. Its performance really just mimics the older 'surface' technology of paper elements. During extreme use or long service, either style of filter is overcome by surface loading, reducing airflow. In fact, the originator of the cotton gauze filter admits that airflow through their filter is reduced 40 percent when it is dirty.
For either technology, ultimate filtering capability is then directly related to surface area. That is why they pleat the filter. But no conventional filter can hope to duplicate the total surface area of a RamFX air filter. Our unique reticulated Aerofoam material has millions of air passages coated with a sticky polymer.
The airborne containments adhere to the walls of the pathways as they wind their way through the 25mm thick, three stage volume construction. Even the smallest particulates, measured in microns, are captured progressively through the entire structure while avoiding the surface loading of conventional filters.
This breakthrough air filtration teknology of a RamFX filter, or Series 10 as it is also called, gives your vehicle the best air filtration possible and a noticeable increase in power due to its enhanced air flow over a longer service life. Horsepower improvements vary depending on the vehicle make, model and year, but a two to eight horsepower increase is common.
It is a lifetime investment for your car and the last filter you will ever have to buy. Conservatively, over 25,000 miles service intervals can be expected before it is necessary to clean and then renew the filter with the available Cleaning Kit.
After every restoration, regardless of the number of times it has been cleaned, a RamFX Series 10 filter will once again perform to its original design capability. That means maximum filtration efficiency, high dust holding capability, low airflow restriction and long service life, while improving engine power. Would you expect less from the best dirty filter in the world?
Features -
• Improved engine performance due to enhanced airflow over a longer service life.
• Traps up to 4 times more dirt than paper filters and up to 2 times more than cotton-gauze.
• Filter is reusable, just clean with PRC solvent and re-treat with DRP treatment.
• Soft, flexible seal conforms to airbox to prevent dirt from getting around filter.
• Achieves filtration efficiency of up to 99 percent.
• Carries a Limited Lifetime warranty.
• World patents pending.
• Retails for $40 to $44 dollars.
Application List, this filter will fit any -
• 1994-1995 Land Rover Discovery Series 1 with the 3.9L V8 engine.
• 1996-1999 Land Rover Discovery Series 1 with the 4.0L V8 engine.
• 1995 Land Rover Range Rover with the 3.9L V8 engine.
• 1995 Land Rover Range Rover with the 4.2L V8 engine.

[Disco]

Unless you have a somewhat modified motor you do not need to change out the current paper filter which does quite a good job, and even then, depending on the type of modification, the paper filter is quite adequate.

[Disco]

Hamrenden! That's quite a story....hmmm, I'll have a closer look at this filter.

[1955diesel]

Think long and hard before you change away from the original spec. which has been tested under every condition you can think of!
If you are going off road, even if you decide to change the element, don't mess with the plumbing or filter box. Unless it is to add a snorkle.
K&N - noisy, let the dirt in, get contaminated quick, often not located well for wading, but on clean hard roads will give a little extra power.

[AdrianL]

Called dealer, called my mechanic and they both are against K&N due to the gunk build up on MAS and also, paper does sufficient job for the vehicle's spec. So, sticking with OEM!!

[Jonesy]

FYI - I bought the K&N for on-road driving, I switch it when off road - dirt roading etc to the paper one, then toss it after a few "expeditions".

This allows me the extra power on road and no worries off road with dirt buildup.

It is so easy to change I don't worry about it.
I LIKE THE SOUND DIFFERENCE OF THE K&N

[troverman]

I have a K&N filter on my 92 RRC and am contemplating one for my 95 RR 4.0SE. I took the entire metal housing off on the Classic and just have the filter sitting there. (I don't go wading with it) Filter looks great and some tiny little bit of extra power, but more importantly 1mpg better on the highway. I also run one in the stock housing on my Mercedes E320.
As far as I'm concerned about oil coating the mass airflow sensor, if the K&N filter wrecks it they can buy me a new one.

[AdrianL]

MAS because they stand by their product.
So, if I use and if I am SOL, I will have to spend $600 for new MAS OR get rid of headache and go for OEM?
I am going with OEM since there is not significant performance or MPG differences.

[Serg]

Well I finally installed the filter K&N sent me... will do a write up after I run through a few tanks of gas.


Serg

[jeffreydv]

I have been running a K&N for over a year now with no problems. MAF works fine.

[azpaquin]

K&N being one. I cut the whole air filter housing off and just tossed a cone K&N on.. it sounded cool, but didn't do crap. Too much heat off the engine.

I put another OEM housing on, OEM filter and everything ran basically the same.

I put a K&N in the OEM housing and ran that for a while.. runs about the same.

I see about maybe 1/8 mi better gas mileage, but did not know if that is because the weather was colder, lower dewpoint and the gas was atomizing better.

I would thing the better setup is to toss a nice little hood scoop in the left front, build a nice airbox to force the air into..put in a nice different cone setup onto some nice 3 in piping...

if you are going nutcase offroad.. those snorkels..

[Disco]

This K&N subject comes up regularly as a search of the archives will show. The brutal reality is, fitting a K& N filter onto a stock Discovery, or any other vehicle for that matter, will delivery you Jack S*#t in extra horsepower. If any, it will be so slight that you won't notice it. Unless you are proposing to do other engine/breathing modifications, you are best advised to stay with the paper filter you already have. At least you don't have to maintain/oil it.

[siam]

K&N isn't so bad in Non-dusty conditions , that right there just about describes non-off road use. In all my dirtbikes and supermotos I make sure I have foam filters on, seems to keep the dust off much better...

[SCSL]

K&Ns have been known to blow the mass air on Discos,,, bad enough on a DII but even worse on a DI. I have one but plan on going back to stock when it's time to clean/replace it. I would rather just replace frequently due to extreme dust & dirt on CO trails.