K & N

[Drivbiwire]

Had a fellow forum member come over with a car he recently purchased. The car needed all the servicing done (Timing belt, oil, complete filter service, Brake fluid, DG oil-bypass).

During the filter replacements I got to the airbox and was was reminded just how good the OEM "Cold Climate" filters really are...

Any guesses what filter was in this airbox...{hint: the writing is on the wall}

Friends don't let friends run a K&N!

This car may as well have not been running ANY filter at all as bad as the dirt, dust and contaminationwere. This goes without saying why people have MAF issues.

DB

 

[WB9K]

Dusty area?

I see you're in ID. Has the car been in a very dusty area? I've said myself that I would not use a K&N if I were driving a lot in dusty environments, like construction sites, etc..

Was the MAF failing? Oily? That dust looks pretty dry.

dh

 

[andreigbs]

Indeed, first thing I did when I purchased my 2nd VW/Audi turbocharged car was to throw out the "performance" K&N filter and replace it with a stock OEM paper filter. It'll stay in there at least 30k before I touch it again, you've done your preaching well, DB.

Whether the dust it oily or dry makes no difference. The MAF gets bombarded by the dust particles kinda like your front end gets all the rock chips in it. If they're oily particles they'll also stick to the MAF element, killing it that much sooner.

 

[Canadian_Grizzly]

Friends don't let friends run a K&N!
DB

Love that line! When I saw the thread I thought oh crap another newbie with an oily filter. Then I saw it was you and I knew some good advice would be inside.

 

[bhtooefr]

/me yanks the (some Japanese characters) Racing filter off of his Miata and puts the stock airbox back on (at least the PO gave me the stock airbox, otherwise I'd have to go to a junkyard for that...)

 

[n1das]

K&N filter = MAF eater + engine & turbo sander = BAD!

K&N filter media compared to OEM paper media:

ZERO performance benefits w/K&N compared to OEM: (K&N "lie detector" test)

Use only OEM filters!

Cold-Climate version of OEM paper air filter:

Cold Climate filter P/N: 1J0 129 620A This is only air filter I use in my TDIs.
non-CC filter P/N: 1J0 129 620 (no "A" on end of part number)

What DBW said!

 

[Matthew_S]

Of course it won't matter what type of filter you use if you don't install it properly. Always remove the whole box from the car when replacing the air filter. It is very difficult to install an air filter in an MK4 without screwing up the seal unless you have the box out of the car.

 

[Matthew_S]

Friends don't let friends let Quickie Lube install their air filters!

 

[dieseldorf]

It's absurd how dirty the "clean" side is. Thanks for reminding us, DB.

Shame on K&N

 

[dieseldorf]

More balls than brains:

7. Will a K&N filter cause my vehicle’s mass air sensor to fail?

No, it is both impossible and ridiculous. It is impossible because we know that the oil treatment on our cotton is very small (usually less than 2 ounces). Once the oil is properly and evenly absorbed through the cotton, no oil will come off, even under extreme engine conditions. It is ridiculous, because no dealership or service provider has ever been able to provide us with evidence to support this “myth,” and in fact, our investigations have revealed that even authorized dealerships are simply speculating and do not have the test equipment necessary to know whether the sensor has failed or why. It is even more ridiculous because some car manufacturers use and sell air filters treated with oil on a regular basis. There are also major brands of disposable air filters that are treated with oil. We all use oil for the same reason, it helps in the filtration efficiency of an air filter. For more information on this topic including videos, see our Mass Air Flow Sensor Statement page.
Out of the millions of air filters we sell, we only receive a handful of consumer complaints each month that a dealership or service provider has blamed a vehicle sensor repair on our product. We take each complaint very seriously and see it as an opportunity to stop a consumer from being taken advantage of. We investigate the situation thoroughly and take full responsibility for resolving the issue. For more information on how we educate and persuade the service provider to reconsider their position, see Mass Air Flow Sensor Information & Testing. We are so confident in our ability to resolve these situations and help a consumer fight back that we offer our Consumer Protection Pledge.

As a result of our standing up for consumer rights and providing assistance to resolve a disagreement, we have had 77 actual sensors sent to us by dealerships who claimed our product had caused them to fail. Microscopic, electronic and chemical testing revealed that none of the 77 sensors were contaminated by K&N oil (K&N Detailed MAF Sensor Test Results). What is perhaps the single biggest clue to what is going on is that over 50% of these sensors were not broken in the first place for any reason. Click here for more information on how this may happen.

 

[WB9K]

Same old bandwagon.

Some real data sure would be nice. So would criteria that sat still. Last week a bunch of guys chimed in to tell me it was the oil that ruined MAFs and this was the reason to stay away from K&N. Today, it doesn't matter if the debris is oily or not. Or if the MAF was ruined.

But here's the real kicker. If I understand the OP correctly (and it reads pretty clearly to me), this car was just purchased used. No info is given about the previous owner, mileage, or what kind of conditions this vehicle has been used in. Most of those things are probably unknown. Who knows where the hell this car has been or what's been done to it? For all we know the previous owner decided to experiment and ran it for months on dirt roads with no air filter at all. Or the previous filter wasn't seated properly--or maybe this one wasn't. Was it? The filter could have been maintained totally improperly. There are A LOT of plausible explanations for what we see here and no way to rule them out (none that have been given, anyway). Why does this not seem to matter to the K&N bashers? (rhetorical question)

In last week's K&N go-round (in which my original question had nothing to do with air filters), I posted several links which I thought would prove interesting to anyone debating the topic. They cite tests by independent people or groups of people which yielded results that would surprise many here. Nobody has commented on them at all. I doubt many even looked at them.

The hardest part about digging deeper when you are sure you know what is happening is finding out just how often you were wrong. I have learned this from firsthand experience, and I suspect several others here who are not prone to speaking in absolutes all the time have as well. The integrity of this forum (and every other technical web forum) depends on the willingness of its participants to dig deep and back up what they say with real evidence. If that evidence is not available, then opinions should be clearly presented as what they are--opinions, whether they are based on a certain amount of experience or not. If we can't at least rise to that standard, then we might as well be swapping naked pictures of each other--it would be about as useful.

dh

 

[dieseldorf]

The aftermarket loves the uninformed, those who believe in miracles.

dh, you're coming in so late and most already regard this "discussion" as

Few of us are still searching for that "miracle" of superior filtration and more horsepower. K&N is a noisy shill. It's a shame they have so much advertising money.

dh, what is your business/commercial relationship with K&N?

 

[WB9K]

I have no affiliation with K&N whatsoever except that I have been a satisfied customer for several years based on my experience with several gassers. I meant to mention that in the last post.

Another question I have about the dyno tests--how quickly will the ECU adapt to sudden changes in airflow? Will it adapt instantaneously, or would it take a while?

BTW, I haven't read all the related threads in the archives, but I've read several. I have yet to find anything that answers my many questions.

dh

 

[dieseldorf]

I have no affiliation with K&N whatsoever except that I have been a satisfied customer for several years based on my experience with several gassers. I meant to mention that in the last post.

Another question I have about the dyno tests--how quickly will the ECU adapt to sudden changes in airflow? Will it adapt instantaneously, or would it take a while?

BTW, I haven't read all the related threads in the archives, but I've read several. I have yet to find anything that answers my many questions.

dh

dh, thanks for your reply. How many HSDI diesel, computer-controlled autos have you owned?

 

[WB9K]

This is my first diesel of any kind. I don't pretend to be an expert, but I have enough sense to see that the info in these threads is not enough to justify a blanket vilification of K&N.

dh

 

[bhtooefr]

OK, so the fact that the TDI is an interference engine isn't enough info to justify a blanket vilification of NOT changing timing belts on time?

 

[dieseldorf]

What benefit have you found with your K&N filter installed in an early 90's GM N/A car? Apart from increase in ambient noise, what else can you document?

 

[WB9K]

What benefit have you found with your K&N filter installed in an early 90's GM N/A car? Apart from increase in ambient noise, what else can you document?

As I said in the other thread, about a 10% increase in fuel economy, most of which is realized during highway driving. Also, MUCH less pedal required when starting from a dead stop--I guess that would be more of a torque gain than HP? Lots of other people have documented similar results, and I'm not talking about K&N.

dh

 

[WB9K]

OK, so the fact that the TDI is an interference engine isn't enough info to justify a blanket vilification of NOT changing timing belts on time?

I'm sorry, I thought we were talking about air filters. Am I the only one who's noticed that NOBODY has stepped up to answer ANY of the questions I've asked?

dh

 

[dieseldorf]

As I said in the other thread, about a 10% increase in fuel economy, most of which is realized during highway driving. Also, MUCH less pedal required when starting from a dead stop--I guess that would be more of a torque gain than HP? Lots of other people have documented similar results, and I'm not talking about K&N.

dh

This is certainly noteworthy. A genuine gain of that magnitude would have many in Detroit (and the "green" coalitions) sitting up and taking notice.

What specifically can you attribute this gain to? How does it make the engine operate that much more efficiently? A 10% gain in fuel economy cannot be ignored.

 

[bhtooefr]

OK, then there's not enough evidence in this thread to justify a blanket vilification of not running an air filter at all!

 

[dieseldorf]

OK, then there's not enough evidence in this thread to justify a blanket vilification of not running an air filter at all!

E, that theory has been tested, too

The air box in the TDi is over-sized for the displacement. The air box and said restriction is not a limiting factor in the power output. Remember: the PD150 cars use the same air box. If the ECU thinks more air is needed, it dials up more boost. It's pretty simple.

E, somebody dyno tested a car last year with the air filter completely removed. While I am not going to search for that thread and documentation, maybe somebody else can quickly locate it.

 

[WB9K]

OK, then there's not enough evidence in this thread to justify a blanket vilification of not running an air filter at all!

Thanks, that's very useful, and totally consistent with my line of reasoning.

Get a grip.

dh

 

[Matthew_S]

As I said in the other thread, about a 10% increase in fuel economy, most of which is realized during highway driving. Also, MUCH less pedal required when starting from a dead stop--I guess that would be more of a torque gain than HP? Lots of other people have documented similar results, and I'm not talking about K&N.

dh

It will take some real evidence before I believe this. Dyno evidence shows this doesn't happen and the fuel economy of my car was not effected when I replaced the K&N that came with my car with a MANN.

One thing we do know to be a fact is that the K&N does not filter as well as OEM. Considering how delicate the MAF is, that can't do any good. I agree that some of the K&N hating that goes on here is overblown but that doesn't mean they are not a waste of time.

 

[WB9K]

This is certainly noteworthy. A genuine gain of that magnitude would have many in Detroit (and the "green" coalitions) sitting up and taking notice.

What specifically can you attribute this gain to? How does it make the engine operate that much more efficiently? A 10% gain in fuel economy cannot be ignored.

It is noteworthy, and I'm certainly not the first to notice. The concept is pretty simple--more efficient airflow = more efficiently burned fuel = better fuel economy if you don't drive like you're in a race OR worse economy if you do drive like that. I know where you're going with this, and I AM in Detroit, in case you haven't noticed. My father before me too, who worked in a prototype shop for 20-some years. He helped build--among other things--the first all-graphite car in the world (a 1976 Lincoln Town Car). I saw cars with airbags and passive restraints as a child in the 1970s. I'm no stranger to the goings-on in this town.

There are, I believe, two main reasons carmakers do not use K&N-type filters as stock parts. First is the up-front added cost. With the hoops the industry will jump through to save a penny per vehicle, any air filter that costs 3 or 4 times what they're using now is a non-starter, period. The industry has consistently proven that it would rather spend millions on lobbying the government about fuel economy than develop better efficiency and alternate fuels. They're only doing it now (reluctantly) because others already have, and the inevitability of peak oil is finally sinking in. They should have got it in the 70s, but they didn't.

The second problem is the liability they would incur with improperly maintained filters. I'm not denying that an improperly oiled or maintained K&N filter can damage a MAF or an engine and I never have. I believe it can. Can you imagine ANY company putting ANY part that requires such close attention in a stock car? They'd be begging for trouble and everybody here knows why. It just isn't going to happen.

dh

 

[tditom]

I can speak from personal experience that an oiled filter (Amsoil, in my case) had no perceptable change on performance.

I did need to replace my MAF within 50 K miles of beginning of use, tho. Needless to say, I have never gone back to an oiled filter.

WB9K- I see you are near Detroit. I can make you a good deal on my Amsoil oil-foam filter, if you want one for your Jetta. I think most folks would agree that it is the equal to the K&N. PM me if interested.

 

[Drivbiwire]

What is there to add, Considering how easy it is to just drop in the K&N, it comes straight from the package "Properly oiled" by K&N...Then when the filter is checked/replaced this is what you find...What is it that you want to know that isn't already "smack you in the face" obvious?

The filter integrity was like new, other than the coating of dust on the "Un-filtered side" and the dust that was puring thru the element.

K&N claims they outflow other filters...I tend to agree, the problem is that they tend to flow a lot more than just air.

DB

 

[andreigbs]

Maybe keeping things in perspective will help. Look at this way: the service manual says air filters should be changed at 40K miles. Just because the filter "looks" dirty doesn't mean it's time to change it at 5k. And those monkeys at Jiffy Lube shouldn't even touch it, but that's another story.

Anyways, at around 40K you pick up a brand-new OEM filter for a whopping $13, which is good for another 40K. So if your engine lasts you 250,000 miles and you don't crash the car or sell it in this time, you'll have spent $82 on just air filters.

Using the K&N filter, you have to figure in the cost of at LEAST one bad MAF caused by the oil. Sure, you could have the MAF go out using the stock paper one as well. But how much more at risk is the MAF with more dust and dirt particles slamming into it? More air flow means less resistance, i.e. filtration.

So you pay the $45 for the K&N, and you buy the $12 recharge kit which is good for about 2-3 uses, tops. Except that to keep the filtration at the best level it can be for the K&N, it needs to be cleaned and reoiled more often than 40K miles. Otherwise you're just letting in all kinds of debris into your engine and turbo, which is like sand in private parts, as DB wittily pointed out.

Not only does the K&N filter not seal perfectly well, unlike the OEM filters which are meant for one-time crush foam seal, but you also spend more on cleaning and recharging, not considering the down-time while you wash it, dry it, oil it and replace it. Add to that poorer filtration at the cost of more flow, which your turbo more than compensates for btw, and you've got an expensive oily mess that will only cause problems sooner or later.

Why chance it? For the 1hp it adds or 5 lbs/ft of torque you just swear you can feel? Turbos are anywhere from $500 and up, MAFs from $120 and up. Why spend $45+$12= $57 for an extra factor to worry about?

Run OEM, change every 40K unless you live in AZ, keep your money for other things. My 2 pennies' worth, anyway.

 

[dieseldorf]

dh, it seems like you're at the point where you've elected to run a K&N filter in your TDI. I'm certainly not going to try to talk you out of it or change your mind.

There are a couple of people here who share their positive experiences with such products. There are many here who will offer a counterpoint. This subject has been beaten senseless. I can see no reason to perpetuate the discussion and I believe there's a forum rule against it.

And with that, I'd like to say "welcome aboard" and may you get excellent service from your new TDI acquisition!

Take care.

 

[Drivbiwire]

It is noteworthy, and I'm certainly not the first to notice. The concept is pretty simple--more efficient airflow = more efficiently burned fuel = better fuel economy

Please explain how this appies to an engine that has every gram of air measured by the MAF sensor, then the air is pumped into the engine. The airflow into the motor is nearly perfectly controlled, OEM air filters have virtually NO RESTRICTION.

Regardless of what the filter is the ECU reads ACTUAL AIR FLOW, commands the turbo to increase or decrease air flow which is already corrected for pressure and temperature variations. The ECU then meters the proper amount of fuel for that corrected flow data...Translated whether you have NO filter or 10 filters the power output remains CONSTANT.

All you have done so far is vomited "Snake Oil explanations" of "Why" an aftermarket should work...sounds great if you have no idea how an engine actually works or is controlled to meet emissions and generate specified power output.

There are, I believe, two main reasons carmakers do not use K&N-type filters as stock parts. First is the up-front added cost. With the hoops the industry will jump through to save a penny per vehicle, any air filter that costs 3 or 4 times what they're using now is a non-starter, period. The industry has consistently proven that it would rather spend millions on lobbying the government about fuel economy than develop better efficiency and alternate fuels. They're only doing it now (reluctantly) because others already have, and the inevitability of peak oil is finally sinking in. They should have got it in the 70s, but they didn't.

That or the K&N type filters CANNOT MEET THE STRINGENT FILTRATION SPECIFICATIONS OF 10-15 MICRONS AT 98% EFFICIENCY while providing air restriction of no more than 15"WC new...AND have a 40,000 mile service life without exceeding 25"WC...Got news for you K&N on their best day can't meet ANY OF THE ABOVE REQUIREMENTS.

The second problem is the liability they would incur with improperly maintained filters. I'm not denying that an improperly oiled or maintained K&N filter can damage a MAF or an engine and I never have. I believe it can. Can you imagine ANY company putting ANY part that requires such close attention in a stock car? They'd be begging for trouble and everybody here knows why. It just isn't going to happen.

dh

So you drive down a dusty road, filter is trashed from dust...How do are you supposed to know? The filter will never be "Restricted" instead it just drops in filtering efficiency thus resulting in the amount of dirt passing thru it!

So you are My. Consiencious...How often are you going to check this POS? Every 100 miles, everytime you drive thru another cars dust cloud, every other day, every other week? Did you realize that in modern race cars (FI, Turbo charged etc) that they DO NOT run these type of filters? Yup, just like the OEM they run those to protect the delicate sensors and turbo compressor blades.

An example of where you will never find a K&N...

DB