K&N Replacement Air Filters

[boogz]

Anyone got any valuable feedback on them in the Mark5 Jetta's? I actually should be asking the GT Golf Boys & Girls aye? Seeing I have the 1.4TSi Jetta...

[golf2nv]

Hi there
I have a golf gti and I fitted a bmc replacement air filter which is like your k&n hi flow and servicable. I did notice a slight pick up in induction noise and it seemed to rev a little bit happier but nothing to dramatic. If your after great gains the way to go is a complete intake which does away with the standard airbox (I'm in the process of getting a neuspeed just waiting for my mechanic to get some into the country I'm getting itchy waiting!!!!!) check out to see if they do one for your model

[Greg Roles]

Having done this first, then a full Modshack pod, I will say that only a full pod gave any sort of noticable difference, and even that was still fairly minor.

Get one if you like the idea of regular cleaning. Or the sticker.

You'll gain more by pulling the big leaf grid out of the bottom of the airbox.

[macdoc]

Warning on non-standard air filters

I have see hundreds of dusted engines in my line of work, all the vehicles Im talking about were fitted with K&N air filters.

To all those who have these filters, take the filter out and hold it up to the light and tell me what you see...

make your own decision.

Macdoc.

[Paul_OH]

Having done this first, then a full Modshack pod, I will say that only a full pod gave any sort of noticable difference, and even that was still fairly minor.

Get one if you like the idea of regular cleaning. Or the sticker.

You'll gain more by pulling the big leaf grid out of the bottom of the airbox.

Agreed, there was a slight induction noise also installed at the same time as removing the leaf grid. I ended up purchasing the Forge intake http://www.forgemotorsport.co.uk/con...oduct=FMIND010 and am very happy with it. If you want to buy one used (1500-2000km) I'm happy to sell mine for $50 + postage (cost me $118 new)

[brad]

I tried a FinerFilter oiled foam unit in my Bluebird & it made no quantifiable difference.
Then I tried a PiperCross oiled foam filter in the Liberty with the same effect. I tried both filters back-to-back with clean paper filters to make sure.

I've decided that aftermarket filters aren't worth the maintenance, mess & cost and would rather replace the OEM grade paper filter more often.

[bazzle]

I have see hundreds of dusted engines in my line of work, all the vehicles Im talking about were fitted with K&N air filters.

To all those who have these filters, take the filter out and hold it up to the light and tell me what you see...

make your own decision.

Macdoc.

Yes ... At last...

I too have been around a long time with motors etc, Ive never seen quantifiable gains with inlets with modern oem filters.

Bazzle

[macdoc]

The oiled type foam air filter are certainley better for filtering the air, they too suffer from problems that most people won't realise, the 'foam' filter oil used is usually very sticky, most people use too much, it will damage the oxygen sensors (lambda sensor) in the exhaust system if it gets drawn through. It coats the sensor and will make it respond slowly, there is no way of cleaning them afterwards.
There are a total of 4 sensors in the Jetta 2 litre FSI exhaust system - hate to think what there replacement cost would be...

Paper filter media is the best there is for filtration - OEM

Macdoc.

[Logzy]

I have see hundreds of dusted engines in my line of work, all the vehicles Im talking about were fitted with K&N air filters.

To all those who have these filters, take the filter out and hold it up to the light and tell me what you see...

make your own decision.

Macdoc.

Agree.
K&N air filters are a POS and just let dust through to the engine.

[Blitzen]

it will damage the oxygen sensors (lambda sensor) in the exhaust system if it gets drawn through. It coats the sensor and will make it respond slowly, there is no way of cleaning them afterwards.
There are a total of 4 sensors in the Jetta 2 litre FSI exhaust system - hate to think what there replacement cost would be...

Paper filter media is the best there is for filtration - OEM

Macdoc.

Just curious to know how the Lambda sensor in the exhaust would get damaged by the oil if the oil has already been burned in the combustion process...

I have run a oiled filter(both BMC and K&N, pod type and panel) in all of my cars and NEVER had any dramas, but its up to you, the operator and basic maintainer of YOUR vehicle, and at the end of the day, its your money...I personally love them...
This whole oiled filter thing has been done to death in several threads accross a number of makes on this forum...Put a bullet in the puppy and be done with it, becaus it always ends in pain(much like the whole APR/GIAC/REVO thing).
Like the guy did in his initial post, and the advice he has gleaned from it, always do your research.

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=22443&highlight=K%26N+Filter

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=19317&highlight=K%26N+Filter

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=18832&highlight=K%26N+Filter

http://www.knfilters.com/MAF/massairpledge.htm

http://www.knfilters.com/MAF/massairfindings.htm

http://www.knfilters.com/MAF/MAFTestresults.htm

[brentondm]

it will damage the oxygen sensors (lambda sensor) in the exhaust system if it gets drawn through. It coats the sensor and will make it respond slowly, there is no way of cleaning them afterwards.

Macdoc.

so that means that compression braking in a petrol engine will also ruin the narrow band oxy sensor......


I think you're mixing your sensors, oil can muck up an air flow meter, but I've never seen issues on an exhaust mounted oxy sensor, this coming from driving a N14 1.6L with > 240,000 KM on it and eating about a litre of oil a fortnight.

lets not forget that a PCV + CCV will blow more oil into the intake manifold than what is in your filter.

[Blitzen]

X2...Thank you!! The amount of engine oil that gets passed will always be more than the minute amount of oil that is in an air filter.

[macdoc]

Sorry for not being more specific, but the air filter oil used by most foam filter manufacturers does not break down like engine oil. The stuff does end up inside the exhaust system, I couldn't tell you what happens to this stuff after the catalytic converter due to the high temperatures generated by these units, but the sensors before the catalyst can be affected.
Simple answer for this is to oil your foam air cleaner with engine oil like we all use to.

This does NOT apply to the pleated cotton filters. ie. K&N and BMC.

[Transporter]

Sorry for not being more specific, but the air filter oil used by most foam filter manufacturers does not break down like engine oil. The stuff does end up inside the exhaust system, I couldn't tell you what happens to this stuff after the catalytic converter due to the high temperatures generated by these units, but the sensors before the catalyst can be affected.
Simple answer for this is to oil your foam air cleaner with engine oil like we all use to.

This does NOT apply to the pleated cotton filters. ie. K&N and BMC.

I'm sorry but you're still not more specific.
Who is? "we all use to"
I don't know but I don't put motor oil on the foam air filter.
I have Unifilter foam filter on the 99 Subaru Forester (the fuel economy was greatly improved and engine oil stays clean up to almost 3,000km) with now problems, however I'm against foam air filters in general.
If you have enough experience in automotive industry you should know that you can't use motor oil on the foam air filter the foam air filters use oil made for that purpose by that particular filter manufacturer (at least it applies to most of them). You can damage the foam of the filter if you put different oil on it. Instruction which came with the foam filter has to be followed carefully otherwise you get even less air filtration and your engine’s life will be reduced.
The OEM filters are the best suited for most of the car owners however some people like to experiment a bit and they can do that it is their car. Since they already came to this forum and ask about the foam filters it is very likely that they will do more searching on the internet and they will find more posts on the topic, some will be positive and some negative and it is up to them to make the informed decision.
But your post could be more helpful, if you upgrade your profile, so people know who is posting. Is it the automotive technician or just another armchair expert? Otherwise they will still attack you post, especially if it’s related to K&N, which BTW I’m with you that K&N provide very little air filtration.
Please don’t get offended I always go strait to the problem.
If you have more information on how the sticky oil from the foam air filter could end up on the OXY sensors or other sensors in the exhaust system could you share it with us on this forum? I think it is possible but more info is needed incl. The source where is it from.

[Blitzen]

Sorry for not being more specific, but the air filter oil used by most foam filter manufacturers does not break down like engine oil. The stuff does end up inside the exhaust system, I couldn't tell you what happens to this stuff after the catalytic converter due to the high temperatures generated by these units, but the sensors before the catalyst can be affected.
Simple answer for this is to oil your foam air cleaner with engine oil like we all use to.

This does NOT apply to the pleated cotton filters. ie. K&N and BMC.

how is the Foam filter oil resistant to being burned in the combustion process as opposed to the Cotton filter oil? As you should know, the combustion tempretures reach up to 1200 degrees C at peak burn. This is enough to burn off just about anything. Even if it dose make it past the burn process(Highly unlikely), why would it have an effect on the sensors as opposed to other conteminates like acids produced by the burn process, and unburned fuel and particulates.