K&N Air Filter

[antichrist]

You mean like the fact that they've been proven to not filter as well?
Or maybe you mean the fact that if you use a K&N off-road it voids the warranty?

 

[Team Jeff]

Schafari, I must respectfully disagree. The fact is that it WILL damage a maf sensor if the user applies too much oil to the filter after cleaning. K&N's come out of the box pretty greasy too. If you insist on using it, please clean it first & lightly oil. Which of course depletes some of it's dirt catching ability. It's a loooose ~ loooose.

K&N has done a fantastic job of marketing it's filters - It's not the product that's driving sales.

Sort of unrelated, but years ago I had a turbo V8 car with a big open air conical K&N on it - after a couple pulls under boost the filter was devoid of oil! The turbo had sucked it all out, it was almost totally white! That's never going to happen on the LR3, but interesting none the less.

 

[schafari]

So I agree with you Team Jeff, if you don't follow directions and saturate the filter in oil, sure, yes, bad things can happen. You know, same thing if I don't follow direcitons and use corn oil rather than motor oil. . . Or if I put RV anitfreeze in instead of LR anitfreeze;-) The simple thing is. . .follow the directions and don't saturate the filter. It is very easy to do it correctly.

Sorry AntiC. . .they actually have been provend by independent labs to filter mor than effectively while passing more air CFM. Where did you hear the rumor that "if you use a K&N off road it voids the warranty?" The K&N warranty or the LR warranty? It can't be the K&N, as it is covered for the million mile unless you customize/modify your LR3 for specialized use in an off road application. If you modify it and use it as a dedicated off road vehicle such as a dedicated dune buggy. Even then, it still has a warranty as stated below.

By the way, K&N even goes so far as to provide you with an engine protection warranty as well. That is below also. It even covers sensor replacement. . . No sense scarring people by all this. The K&N filter is a proven system when used correctly.

MILLION MILE LIMITED WARRANTY
K&N O/E Replacement Air Filters and Air Intake Systems purchased from Authorized Dealers are backed by a Million Mile Limited Warranty when used primarily on paved roads and on vehicles for which they were designed. If one of these products ever fails to provide complete satisfaction, K&N will replace it.

WHAT IS NOT COVERED BY OUR WARRANTY
Any K&N product used for 1: any type of racing or competition; 2: any off-road use, custom or modified applications; 3: any off-road or dual sport motorcycle/ ATV use; or 4: any illegal highway use, marine, or industrial applications. All K&N Air Filters not covered by our million mile warranty are warranted against defective materials or workmanship for one year from date of purchase with no mileage limitation. This includes K&N Air Filters sold for ATV's and off-highway or dual-purpose motorcycles.


ENGINE PROTECTION LIMITED WARRANTY
Unlike many companies, our warranty for O/E replacement air filters and intake systems does extend beyond the replacement of a defective K&N part. For the original purchaser of the product, our warranty covers any engine damage or related costs incurred as a direct result of the use of a properly installed and maintained K&N O/E replacement air filter or intake system on the specific vehicle for which the product was designed to be used by K&N. This includes reasonable vehicle repair costs, sensor replacements, car rental fees or other incidental expenses directly related to an engine problem caused by the failure of a K&N product. Furthermore, we warrant that using our product will not result in a vehicle warranty denial. K&N will not be responsible for any indirect, consequential, special, contingent, or other damages not listed above.

We will promptly reimburse the consumer for the cost of the repair if a service provider denies warranty coverage as a result of a K&N product or claims that a K&N product has caused harm to your engine or vehicle. In order to receive reimbursement, we require each of the following:



The consumer must provide a written statement or repair order from the dealership or service provider in which the dealership or service provider blames the problem or warranty denial on a K&N product;
The service provider or consumer must provide K&N with all allegedly damaged parts. Many states have laws that require a service provider to retain all parts replaced during a vehicle repair, unless given consent to dispose of the parts by the consumer. K&N will pay the shipping cost to recover these parts; and
The consumer must provide proof of purchase of the K&N product along with cooperation in helping us investigate the claim.
Once these steps have been completed, K&N will contact the service provider and collect evidence to support their claim. In the event we are not provided with sufficient evidence, we reserve the right to reject the claim and will use our best efforts to assist in establishing your rights toward the service provider under warranty or other provisions.

We strive to exceed consumer expectations. Customer service can be reached at 1-800-858-3333.

 

[schafari]

Ironically, in trying to find some stats on K&N problems. . .I came across these items which discuss the ah um, myths or facts depending on your religion that we were disucssing here. . .

Common Misdiagnosis in Warranty Repair

There are many reasons why a dealership or repair facility may deny warranty coverage on a repair. Sometimes, people make mistakes, and technicians are no different than anyone else. A less common reason is the few "bad apples" out there who try to charge a consumer for a legitimate warranty repair, so they can make a greater profit. You don't have to be a master mechanic to challenge a repair diagnosis, just an educated consumer. In all of these cases, you should contact K&N's Service Provider Support group at 800-858-3333. Here are some preliminary resources that might be helpful.

Problems related to the use of an "aftermarket oiled air filter"
Maybe you've seen this phrase on your repair order. The dealership or repair shop says that certain engine parts or sensors need to be replaced because you have been using a K&N air filter. The truth is that oil does not come off our air filters, even under extreme conditions. The amount of oil applied to our air filters is small (usually less than 2 ounces) and once that oil is applied and evenly absorbed it will not come off until the filter is cleaned. We conducted a test with an over-oiled K&N air filter in which we flowed 1,000 cubic feet of air per minute through the filter for over twelve hours. The use of an absolute filter downstream revealed that no oil came off the K&N air filter, even in these extreme conditions. Many companies, both aftermarket and OE, use oil in their air filters, both disposable (paper) and reusable (cotton). We all use oil for the same reason: it enhances the filtration efficiency of an air filter.

Mass Airflow Sensors
The dealership or repair shop says that your vehicle's mass airflow sensor needs to be replaced, and is blaming it on the K&N air filter you installed. What steps did the technician take to arrive at that conclusion? We have never encountered a dealership or repair facility that owned the equipment necessary to test whether or not a sensor was functioning properly or to measure its output. Certain vehicle manufacturers have issued bulletins on how to test a mass airflow sensor by installing it into a "similar vehicle", but in our experience those instructions are rarely followed. There are two common types of mass airflow sensor failure: failure from silicone contamination of the sensing element, and complete electronic failure. Both of these types of failures can only be verified through microscopic, forensic/chemical, and airflow/sensor output analysis. More on Mass Airflow Sensors here.

Dust Ingestion
The dealership or repair shop says that your K&N filter let too much dirt pass through, causing premature engine wear and "dusting" of your turbocharger or engine. Dust ingestion can be hard to verify without doing a complete teardown of the engine and performing a filtration efficiency test on the air filter. Performing an oil analysis on the engine oil used at the time of failure can uncover a dust ingestion problem. If a dust ingestion problem is found, it is most likely caused by an opening or defect in the air box or air inlet duct, a fuel filter that needs replacement, or engine oil beyond its service life. It is unlikely that an air filter is the cause.

 

[schafari]

Ok, last one I promise. . . Check out the testing and facts below. To me, this is a company I like. Willing to go to bat for the consumer against BS. I don't work for K&N nor have any interest in them what so ever; other than, it kind of is a bummer that some post "feelings" rather than actual facts on this topic.

K&N Mass Air Flow Sensor Statement

Every stock replacement air filter we sell comes with this sticker, which we advise consumers to place prominently on their air box. The sticker is to alert service technicians that they should not throw away your K&N air filter because it will last for the life of your vehicle. When service technicians see this sticker it means “STOP SELLING THIS CUSTOMER DISPOSABLE AIR FILTERS OVER AND OVER.” In our opinion, this is why some dealerships or service providers may attempt to discourage a consumer from using a K&N air filter or worse blame a vehicle repair on our lifetime air filter. Most dealerships provide excellent service and fulfill car warranty obligations without issue, argument or tardiness. The rest of this discussion is about a minority of dealerships who are either misguided or misinformed.

We are aware of the “urban myth” (K&N News Story) created by a few dealerships that a vehicle's MAF sensor can be contaminated by K&N filter oil. No evidence has ever been provided to support this “myth” and three years of diagnostic testing by K&N has shown that not only is this allegation not real, it is not even possible. In our opinion, it is an excuse for a dealership and/or the vehicle manufacturer to avoid a legitimate warranty repair. In the last 4 years, we have sold over 10,000,000 lifetime air filters and received only a few hundred calls from consumers who are having dealership or service provider challenges. We believe that Dealership's or service provider's real incentive may be to discourage the use of reusable products so they can sell disposable products over and over. In order to provide consumers with added comfort that they will not be placed in a bad position by an improper warranty denial, we offer our Consumer Protection Pledge.

K&N MAF Sensor Videos

Mass Air Flow Sensors
Intro & Test Results Summary

Can Oil Come Off Our Filters?
High Airflow Testing & Engine Air Filter Dynamics
What Does It Take to Foul a MAF Sensor?
Extreme Testing
What Can Contaminate a Mass Air Flow Sensor?

No dealership or service provider, when contacted, 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. In the last 4 years, we have had more than 100 actual sensors sent to us by dealerships that claimed our product had caused them to fail. Microscopic, electronic and chemical testing revealed that none of these 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 sent to us were not broken in the first place for any reason. Click here for more information on how this may happen.

The oil treatment on our cotton is very small (usually less than 2 ounces) and is a critical component of our filtration technology. There is nothing unusual about the use of oil as a tacking agent to improve air filter efficiency. In fact, certain Ford Motorcraft and Fram disposable air filters are treated with oil. This makes us wonder if it is only the oil treatment from reusable lifetime air filters that is alleged cause a vehicle problem? The idea that oil comes off our filter throughout its life is truly ridiculous. Just like oil treated disposable air filters, once our oil is properly and evenly absorbed through the cotton, no oil will come off, even under extreme engine conditions. We have even conducted a test with an over oiled K&N air filter in which we flowed 1,000 cubic feet of air per minute for over twelve hours (few cars or truck could generate even 500 cubic feet of air flow). The use of an absolute filter confirmed that no oil came off the K&N filter tested, even in these harsh conditions.

We have tested many MAF sensors claimed to be damaged. We can fully diagnose their condition and likely cause of failure. For a full discussion of our MAF sensor test protocol and findings, see K&N Mass Air Flow Testing Results and Findings.

Not one of these suspected MAF sensors sent in for laboratory evaluation was shown to have failed due to contamination from K&N filter oil.

We are the solution

We are so confident about our testing and the quality of our product that we offer a Consumer Protection Pledge. So if you ever get in a bind with a dealership, call us because we are the solution.

 

[schafari]

Ok, so I spoke to soon. This will be the last one. I post this because it is very interesting, factual, and done by an independent lab. . . What is also interesting, which I never knew, was that the MAF sensors that are contaiminated have been contaminated with silicone; yet, the K&N oil doesn't contain any silicone at all. But guess what, the MAF sensor itself uses a big glop of silicone inside the casing.

K&N MAF Sensor Test Results
January 2004 through June 2010

K&N has millions of satisfied customers, yet we do occasionally get instances where a dealership or service provider has blamed our product for a vehicle problem. We attempt to resolve these misunderstandings by speaking directly to the service technicians. In any event, we take care of the consumer through our Consumer Protection Pledge. In issues regarding MAF sensors, we have been able to recover many of the allegedly “bad” sensors and test them to diagnose the actual cause of the failure. In most of these cases the "bad" sensor was actually functioning properly and was misdiagnosed by the dealership or service provider. The diagram below is a summary of our findings.



Of the 106 sensors we received that were truly malfunctioning, 39 had a complete electronic failure in which the sensor's voltage output was a flat line, generally caused by a connection or circuitry problem within the sensor. When a sensor is responsive but it's voltage output is not within the normal limits we refer to this as "out of range". This condition can be caused by circuitry problems and it can also be caused by a sensor's thermistor becoming dirty or contaminated. We sent 29 out of range sensors to an independent laboratory for an elemental and chemical analysis and all of them were found to have silicone as the contaminant.

Silicone is used on the circuitry of these sensors because it acts as an excellent thermal and electrical insulator, inherently sticks to most surfaces, and is resistant to moisture and heat. Some MAF sensors use a high temperature burn-off cycle to eliminate normal engine contaminants from the sensor. Silicone is resistant to this process.

Thermistors are used in MAF sensors to measure the transfer of heat from the thermistor to the air passing by the sensor. A thermistor's resistance changes as its surrounding temperature changes. The greater the air mass and air flow the greater the transfer of heat. When a thermistor is "silicone contaminated" the thermistor becomes insulated and can result in an out of range condition.

In addition to out of range sensors, functioning and failed sensors have also been sent to an independent forensic laboratory for analysis. A few of these sensors were found to have trace amounts of oil on the thermistor. The amount of oil was so minimal that an accurate analysis of the oil's source could not be determined. The trace amount of oil can conceivably be found from two possible sources: fuel in the combustion chamber or motor oil used as an engine lubricant that gets suspended in crankcase vapor. Our experience in the lab is that trace amounts of oil don't change the sensitivity of the sensor enough to cause an "out of range" electronic signal. Furthermore our testing has shown that K&N air filter oil will not come off a K&N air filter even in extreme conditions. More on this topic here.

As of the date of our last test shown below, K&N air filter oil cannot be confirmed as the source of contamination on a sensor nor can any oil type be attributed to a sensor’s failure.


MORE DETAILS ON SILICONE & TESTING
Mass Air Flow Sensor Electronic Testing at K&N:

The MAF sensor is placed on a test bench designed and built by K&N Engineering. The test bench can flow air through the sensor at variable flow rates, ranging from idle to full throttle. The flow of a sensor is then compared to a new sensor.

Microscopic Examination:

When a service technician looks at a MAF sensor's thermistor what they see with their ***** eye is very little. It is nearly impossible to determine if a MAF sensor's thermistor is dirty or clean from looking at it without magnification and good lighting. When K&N views a MAF sensor, we look at it under a microscope.

A MAF sensor is located under the hood of your vehicle and is subject to a heat, cold, vibration, etc., in other words, a hostile environment. An engine performing as expected can contribute to contaminating a MAF sensor. The presence of gas fumes, a vehicle backfiring, combustion blow-by and even water condensation can contribute to contamination of a sensor. Ironically, the presence of contamination does not necessarily conclude the sensor is not functioning properly and requires replacement.

Independent Forensic Analysis:
An elemental and chemical analysis of the contamination has more often than not shown to be silicone. K&N filter oil does not contain silicone. The silicone can actually be traced to the sensor’s housing of the electronic circuitry. The silicone can seep out of the housing area onto the sensor.


MAF sensor thermistor probes connect to the circuit board. Silicone covers the circuit electronics and it can seep down contaminating the thermistor. This photo shows the silicone compound referenced, covering/protecting the electronics. The probes leading to the thermistor are connected to the underside of this circuit board.
This photo shows a probe demonstrating the stickiness of the silicone material.
This photo shows a sensor with silicone covering the electronics. Note the small gold processor in center.
This photo is a close up of the processor under the silicone.
This photo is an extreme magnification of the processor. As can be seen, this is a complex sensor with thousands of connections and components all of which must be intact for the sensor to function properly.

Below is a more detailed summary of our actual test results.

Quantity Initial Sensor Test Electronic Test Result Microscopic Examination Independent Laboratory Chemical Analysis Probable Cause
Electrical Conduction Failure within Sensors 17 Bad Failure Clean N/A Electrical Failure
9 Bad Failure Dirty N/A Electrical Failure
4 Bad Failure Dirty Silicone Electrical Failure
1 Bad Failure Dirty Trace Oil Electrical Failure
8 Bad Failure De-lamination N/A Manufacturing Defect
21 Bad Out of Range Clean N/A Electrical Failure
16 Bad Out of Range Dirty N/A Electrical Failure
29 Bad Out of Range Dirty Silicone Electrical Failure
1 Bad N/A Dirty Silicone Severe Silicone Leak
106 BAD
Normally Functioning Sensors * 111 Good Normal Clean N/A Sensor Never Failed
48 Good Normal Dirty N/A Sensor Never Failed
2 Good Normal Dirty Dirt Sensor Never Failed
28 Good Normal Dirty Silicone Sensor Never Failed
2 Good Normal Dirty Trace Oil Sensor Never Failed
2 Good Normal Dirty Trace Oil & Silicone Sensor Never Failed
193 GOOD

Electrical Failure: Electrical issue within sensor compared to a new sensor's specifications
Manufacturing Defect: A layer of the membrane sensor peels back causing electrical failure - known as de-lamination
Sensor Never Failed: Service provider error; sensor was not malfunctioning
Severe Silicone Leak: The silicone leak was too severe to run on the test stand

* Well over 50% of the "damaged" sensors sent to us were functioning properly meaning they were never damaged in the first place and cannot be attributed to any vehicle problem. Click here for more information on how this may happen.

Below is the list of MAF sensors that were sent to K&N for testing. The list includes dealerships that misdiagnosed the problem and blamed a K&N product for the failure. Test results are also shown.

K&N FILTER OIL HAS NEVER BEEN CONFIRMED AS A SOURCE OF CONTAMINATION ON A MAF SENSOR!

 

[Team Jeff]

The amount of oil applied to our air filters is small (usually less than 2 ounces) and once that oil is applied and evenly absorbed it will not come off until the filter is cleaned.

I can tell you from first hand experience (with my turbo car) this is statement is simply not true. Which leads me to believe other "facts" presented by K&N may be lacking some truthfulness as well.

 

[Team Jeff]

Dust Ingestion
The dealership or repair shop says that your K&N filter let too much dirt pass through, causing premature engine wear and "dusting" of your turbocharger or engine. Dust ingestion can be hard to verify without doing a complete teardown of the engine and performing a filtration efficiency test on the air filter. Performing an oil analysis on the engine oil used at the time of failure can uncover a dust ingestion problem. If a dust ingestion problem is found, it is most likely caused by an opening or defect in the air box or air inlet duct, a fuel filter that needs replacement, or engine oil beyond its service life. It is unlikely that an air filter is the cause.

I've got to call shena****ns on this one too.

I had a K&N on a Honda XR600R dirt bike and noticed when I'd clean the filter that there was dust on the carb side of the air filter housing, I was pretty surprised because at the time I really thought K&N filters were AWESOME (I still think they look cool). My first thought was that the dust must be getting in past the seals so I bought some K&N grease specifically for sealing around the mating surfaces. Guess what- after the next ride the dust was present again. I reluctantly decided go back to an oiled foam filter. For those that haven't used a foam unit, the oil is EXTREMELY sticky & thick. Nothing like the thin WD-40 like oil used in cotton gauze filters.

The foam filter's are a PITA to service but they sure do the job. I never had another dust issue post foam.

For an application like the LR3 a K&N makes absolutely no sense to me. If you use the car offroad & don't clean it at reasonable intervals it WILL shut the vehicle down. I know this first hand as well after seeing it happen to a friends F-150. Do you really need that extra 5hp? Thats being generous and assumptious. I guarantee any performance gain you feel has been manufactured by your (not yours specifically) noggin, possibly with a little help from you ear canals - I've experienced increased intake sounds using K&N's. Sounds cool.

Road race car? Sure, run K&N's if they sponsor you. The engine will need freshening long before the tiny dust particles do any damage. I guess a boat or jet ski would be a good application too.

 

[Team Jeff]

Interesting test detailed here -

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

"In 60 minutes the AC Filter accumulated 574gms of dirt and passed only 0.4gms. After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms.

Compared to the AC, the K&N“plugged up” nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. See the data tables for a complete summary of these comparisons. "

 

[schafari]

That is some interesting data. And I would agree, if you are going to use your LR3 as a dedicated off road vehicle, or if you use it in the dessert, etc., where max dirt filtration is key, I would not use a K&N. Also, you left out the key summary finding. The K&N does indeed flow more air in a normal environment. (See below)

However, that constittues likely a tiny statistically insignificant portion of LR3 owners. Sure we take our LR3 off road every so often, but most of us don't have a constant stream of dirt/dust blowing into the air intake.

Conversely, what we do have, is a constant stream of normal air blowing in. The results of the very study that you point out support the fact that the K&N had "less restriction to flow." As your study below states, it is a tradeoff between "dirt capturing ability" and maximizing air flow. (By the way, if you are worried about your engine because of the differential between the dust/dirt that the K&N may pass as compared to what the OEM paper filter will pass. . .I want your life, as that worry is really really easy to deal with.)

The text below is the summary findings from your article:

"The Flow Restriction response curves for each filter have the same basic shape. However, note how the AC Filter, which passed the smallest amount of dirt and had the highest dirt capacity and efficiency, also had the highest relative restriction to flow.The less efficient filters correspondingly had less restriction to flow.

This illustrates the apparent trade-offs between optimizing a filter for dirt capturing ability and maximum airflow."