Thread: First K&N filter clean, I wish I had millions of dollars

Originally Posted by joel0407

Someone on here recon the only test for an air filter was an oil test. So here is my Skoda Yeti after 15,000km with a K&N including a reasonable amount of dirt for a Yeti, Gunlom Falls and a few other NT roads in the dry season.

There oil analyst guy mentioned the high Aluminum but he didn't know this was only second oil change for this motor and it's still wearing in. Also plenty others have noted high aluminum on the 2.0TDI VW motor. Even though he mentioned it as high, it's only 18ppm and 10 - 30ppm is acceptable and it's more of a problem if it's seen with high silicon which it isn't.

Happy Days

Why would you put a k$n on a yeti?

There is zero performance potential as they are not limited by airflow. There is no gain in fuel economy as the stock filter is decently oversized and tour maintenence increases. Stock filters don't need touched on 15,000km and are also cheaper.

This is even ignoring the better filtration of the stock filter.

The issue with the D2 TD5 which has been documented many,many times is the air bypasses the filter.This causes fine dust downstream of the air box.The airbox is a shocking design.

Difficult to fix permanently,although i found grease around the seal helped,as did a snorkle as less dust was sucked in to start with.

A K&N filter may fit in the air box better than a paper element,and allow less bypass,also some oil on the airbox seal may also help.

I found sealing of the airbox an issue in all three D2s i had,another issue LR were not interested in solving.
It is also amazing that it does not seem to effect engine wear,although it does shorten the life of the MAF.

Originally Posted by scarry

The issue with the D2 TD5 which has been documented many,many times is the air bypasses the filter.This causes fine dust downstream of the air box.The airbox is a shocking design.

Difficult to fix permanently,although i found grease around the seal helped,as did a snorkle as less dust was sucked in to start with.

A K&N filter may fit in the air box better than a paper element,and allow less bypass,also some oil on the airbox seal may also help.

I found sealing of the airbox an issue in all three D2s i had,another issue LR were not interested in solving.
It is also amazing that it does not seem to effect engine wear,although it does shorten the life of the MAF.

It's been suggested that the oily intercooler helps catch the dust. I'd be interested to see how two Td5s wear over time, one with a provent from new and one without. But it's true, you rarely hear of Td5s dusting, and even if you do it's normally due to a catastrophic failure of the air filter, mainly due to poor fitting or neglect. I think I know of maybe 4.....5 tops

Originally Posted by rick130

Bingo.

High Si in particular will show with a K&N in dusty conditions, as well as elevated Pb, Al and Fe.

Silicon is used in some/most oils as an anti-foaming agent, but it's noticeable on a UOA when it's dust ingestion.

One of the South Africans posted some really good pics probably a decade ago on one of the now defunct UK boards of a 300Tdi with 80,000km of K&N use in predominantly dirt road conditions.

Every bore was totally stuffed, required a maximum re-bore. (and it wasn't a case of soft bores)

isuzurover also recounted the story of an F1 engine manufacturer that used K&N's until the first race in the middle east where they dusted multiple engines from the constant sand blowing across the circuit.
IIRC air flow and face velocities were pretty high, (naturally) but it's a pretty good illustration of what can happen.

My oil sample was done in response to one of these posts. There were 3 or 4, I think.

I have relied on K&N air filters for years and never had one fail but I have seen more than one paper filter fail.

I started this thread just because I had a paper filter fail and then replaced it with a K&N which works so well. I had many who don't believe and they only real test of the filter they could come up with was an oil test. This is not my Disco, it's still coming but the proof is in the pudding.

Show me an oil test with a paper filter that's better.

Yes. I do suspect that it was the air box not sealing on my TD5 but the K&N is well made and a better fit than the paper filters I had used. The K&N filters well, flows well and is made with enough quality that it seals the air box.

Most of the posts since I posted the oil test are just repeating what has already been said.

Happy Days

How many do you want ?
Although you can't compare engines, you are looking for trends with the same engine family and with the same lab.
Unfortunately only on the phone ATM as the computer has pooped itself.

FWIW, and just my opinion, Iron is too high, (although IIRC VW's tend to read pretty high)

Copper is crazy high, copper comes from bearings or bushings.

Silicon and particularly sodium could be better.

Many just use sodium to indicate coolant, but it'll also show up with dirt.

BTW, you need a number of tests to indicate trends.

I really think you'd see a big difference if you ran three/four tests with the K&N and then an OE filter.

K&N's just don't filter as well as a decent cellulose filter Joel.
My old oil analyst told me this, he's read teens of thousand of oil tests and isuzurover is a filtration engineer/designer/consultant

How do you explain the difference between your claims and the results of these tests, some of which are on-the-road tests and some are lab tests?


Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata

K&N Air Filter Review - Debunking the Myths (and why OEM is better)

K&N Air Filters--Snake-Oil Soaked Cotton Gauze

I know that at least one of those tests has been posted previously.

As others have suggested, a simple explanation may be that a properly fitted paper filter will outperform a K&N but a K&N may outperform a badly fitted paper filter.

Is there any other realistic possibility?

FWIW I just dug up a couple of old Patrol TD42T tests and silicon read 1 and 2, copper 2 and 1, Fe 5 and 7 after 7,000km on an ordinary Fuchs mineral oil.

As an aside, I'll make an observation about Unifilter (the Company, not the product.)


When the foam on the Unifilters fitted to my RRC disintegrated, the company refused to honour their lifetime replacement warranty. After much to-ing and fro-ing they finally sold me a new pair at cost price.


They were sure able to filter my wallet.


The warranty period now is just 3 years. This seems to show a low level of faith in the longevity of the product.

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