K&N

Went by the dealer to complain a bit about the quality of the work they do and mentioned to the service manager that they had just installed a K&N air filter for me. He said that Porsche knows about a problem where the oils are getting sucked out of the filter into the mass air sensor and failing the unit. Since the K&N is an aftermarket filter, Porsche is not covering the repair. Anyone have the problem with the filter? Anyone not have it fixed by Porsche?

I asked my dealer about installing a after market filter and they told my of your problem. They made it very clear that it would not be covered under warranty, this is a well known problem.

I concur that id that is the cause they shoudl not cover it. I also know that my Boxster lost its Mass Air sensor with the factory air filter... could they be missing a problem with the mass airs and just blaming aftermarket filters?

My dealer technician has seen a number of them fail the MAF. They also run too rich. $150 for the diagnosis (at a dealer anyway), $380 for the part plus labor. Cannot be repaired by cleaning. If you have one, for sure take it out and thoroughly blot up any excess filter oil. Pretty iffy risk to take considering the trivial performance potential.

K&N performance potential... NONE You can do better (or just as BADLY!) by simply removing the factory filter.

Hi.. do you have more information about the MAF unit? what is this unit really and what does it do? and if ever it fails how will one know about it? Is it accessible by removing the air filter to clean it? Wael 996 C2 1999

My experience with Porsche is if you have an aftermarket part of any kind on the engine and they can even loosely tie it to the failure of one of their parts, they won't cover it under warranty. It seems that when you install an aftermarket part on the engine, you are releasing Porsche from their warranty obligations not just for that part but for everything that is associated with it. This includes aftermarket chips, piggybacks, sport cats, air filters, etc. About the only thing I know of that is safe, is an aftermarket exhaust. Since it is at the tail end of the combustion process, there is nothing they can blame on the muffler. BTW, Porsche will also void your warranty if they find out you have driven the car on the track. I know, I lost my warranty on drive train and emissions for this very reason. They didn't even ask me if I tracked the car, they just assumed it from the "configuration" of my car (roll bar, 5 point belts, fire extinguisher, etc). I have learned my lesson the hard way. There is very little to be gained and a lot to be lost by trying to bolt on performance improvements to the 996 engine. Karl

The mass air sensor measures the mass of air (density and volume) enternig the engine. It typically uses a wire that runs through the air channel the wire changes reistance based on air flow (heat loss I believe) and feeds the info to the DME unit to determine air/fuel mixture with additional input from O2 and other sensors

I have a BMC air filter (similar to K&N) on my 986S. The performance difference is negligible. The only reason for the change was to alter the intake sound... I guess it did make the egine sound a little different, maybe better. But is it worth risking warranty coverage? Of course not...

Thanks for the comments. Going to go down and put the Porsche filter in.

Just an FYI from the K&N website: Contrary to what you may have heard or read, in the USA, a K&N Filtercharger will not void your vehicle warranty. The Magnuson-Moss Warranty Act, passed in 1975, prohibits a manufacturer from conditioning its warranty of a consumer product upon the consumer using any article or service (other than one provided without charge under the warranty) which is identified by brand, trade or corporate name, unless expressly authorized by the Federal Trade Commission. If the manufacturer does not provide air filters free of charge, they cannot void the vehicle's warranty simply because you have installed an aftermarket air filter.

Jason. Your statement is HORRIBLY misleading. The ACT you reference only applies to aftermarket products deemed compatible with or "like/kind" from the original manufacturer, or manufacturer's designated supplier. K&N "WET" filters in NO WAY fit that criteria.

If the filter (either BMC or K&N) is over-oiled it will foul the mass air flow sensor regardless of whether it is a Porsche, Mercedes or BMW. These filters will not void your warranty but... "misuse" will (i.e. over-oiling). I have yet to see a dealer prove that an air filter (of any type) was cause of a MAF failure. There are quite a few MAF sensor failures (on all these cars) regardless of the type of air filter. (I just had one on my Mercedes last month). IMHO of course!

Guys, When you talk about "oil", I hope you're not talking about regular motor oil. I race motocross bikes which use similar foam filter elements. Any motorcycle shop sells special foam filter "oil" which goes on like oil but has an alcohol base which evaporates away leaving a viscous, sticky coating which will NOT be sucked into the intake. The trick is to do your filter at night and let it sit overnight to insure that it "sets". Regular oil will not "set" and in fact will pool at the bottom of the element and from there can get sucked in. No Toil is a great brand. It also washes off the filter very easily. Bel-Ray and Uni also are good.

K&N and (and BMC, I think) air filters use lightly oiled cotton inside a wire mesh as a filter element instead of typical dry paper. Particles are trapped in the oil. They may be cleaned, oiled and reinstalled and therefore have a very long service life. Not the same oil as the foam elements you often see on two-strokes, more like parafin. The performance attributes are rather like premium audio/video wiring--no doubt different than stock, but at most incrementally and dependent on the application. I think the message here is that hot- and cold-wire MAF sensors are inherently fragile, and MIGHT get fouled by excessive filter oil,if present. If you have to pay to fix it, well you could have had any of the smaller aluminum or carbon upgrades instead. So if you run one, it is probably a worthwhile exercise to take some paper towels and blot up any excess oil on the exterior of the thing.

You guys are a wealth of knowledge. The interesting thing about this is I provided the K&N to the local dealer in its box, oiled as it comes from the manufacturer. Clearly the dealer knew what they were installeing and no one told me about the issue. Have checked my bill and there is no note on it telling me I am on my own. I must admit to feeling a bit faster at Summit Point last weekend, until I over cooked turn 1 (Karl where were you? It was my last DE with Potomac), but I agree the incremental gain is not worth the risk. So the long intro to this question. If the dealership installs a part, does not tell the customer of a potential problem and the system fails, where does the fault lie?

If Summit Point is a track, I would not boast about your lap times while you are in for warranty fixes! If Porsche is really not honoring the warranty for MAF repairs due to this (I do not know), there is no question your dealer should have warned you about it. Slow economy, put filter in, diagnosis, repair (warranty or not they get paid), another new filter--connect the dots.

If you watch a K&N comercial you will see them floting a little ball up a tube. This is supposed to measure "air flow." Of course the K&N filter lifts the ball higher. All sorts of claims follow... Just give me a set of before/after dyno's and let me see any supposed hp gain. As I recall, those that have dynoed their cars found little if any hp gain. Some even saw a drop in hp. Bottom line: If it was that easy to get any extra hp, wouldn't the factory have done it? Cheers, Chris

WWest, I'm sorry if you feel the statement is misleading, but unless Porsche offers free filters or specifically prohibits oiled filters (in writing), they cannot void the cars warranty. Here's a link with more information on Magnuson-Moss: <a href="http://www.mlmlaw.com/library/guides/ftc/warranties/undermag.htm" target="_blank">http://www.mlmlaw.com/library/guides/ftc/warranties/undermag.htm</a>

Chris, I agree... but they DO put low restriction filters on some cars. I have nothing agaist K&N but the factory DOES put the BMC filters on GT3 Cup cars as well as GT3R's.

Here's a bit more. Basically, unless Porsche has requested and received a waiver from Porsche, they cannot void your warranty for using a K&N. _______________________________ Under the Magnuson-Moss Warranty Improvement Act and general principles of the Federal Trade Commission, a manufacturer may not make its vehicle warranty conditional on the use of any specific brand of motor oil, oil filter or any other component, unless the manufacturer provides it to the customer free of charge. An equipment manufacturer can obtain a waiver if it proves to the FTC that its equipment will function properly only if specific brands of motor oil, oil filters or other components are used. The FTC must be satisfied that this is in the public interest, and this waiver must be published in the Federal Register. This is considered a "waiver" of the prohibitions on conditions of written warranty. __________________________________________

Oops, meant to say requested and received a waiver from the FTC.

Do any of us, were we sitting on a jury, truly believe the K&N filter is a like/kind replacement for the factory supplied/recommended filter? K&N doesn't even believe so, otherwise they would sell it in the same manner as Fram does, P/N CA3462(??) is a direct replacement/substitute for the factory filter. If a Porsche dealer, of all people, knowingly sold and installed a component that negated my factory warranty, I would fully expect that same dealer to provide his own warranty as a substitute. If he didn't I would then hire a damn good attorney.

Aftermarket cotton filters almost certainly are capable of more air flow than paper filters. They even sound more open in my experience, I have had them. This does not mean a street car application will have a meaningful gain, especially running stock cams, valves and exhaust. That is to say, is the OE paper filter actually overtaxed? Apart from the nature of racing demanding even trivial performance gains at high cost, real race engines only have to last a few hundred miles. So you see them there, right application. A racer also maybe gets compensated to run a particular product. You would think from racing that every sports car ought to ship OE with Goodyears.

The air filter should be an easy case, try like and kind on headers, camshafts, different intake manifolds, computers, etc. It can get dicey.

Yes, Will, I would, if sitting on a jury, truly believe that the K&N filter is a like/kind replacement for the factory supplied/recommended filter. I would, knowing as I do, that many manufacurers offer house-branded K&N filters as their own. Even Harley offers them for their bikes, even the VROD which has a Porsche designed engine. [quote]Originally posted by willwest: <strong>Do any of us, were we sitting on a jury, truly believe the K&N filter is a like/kind replacement for the factory supplied/recommended filter? K&N doesn't even believe so, otherwise they would sell it in the same manner as Fram does, P/N CA3462(??) is a direct replacement/substitute for the factory filter. If a Porsche dealer, of all people, knowingly sold and installed a component that negated my factory warranty, I would fully expect that same dealer to provide his own warranty as a substitute. If he didn't I would then hire a damn good attorney.</strong><hr></blockquote>

As a lurker who hangs out mostly on the BMW boards (but an ex P-car owner x 2), I'd like to clarify the Magnuson-Moss Act. The intent of this act was to prevent manufacturers from having a monopoly on aftermarket parts. They can not require a certain brand name be used in order for the warranty to be valid. They CAN however, require that a certain spec. be met(or require that the aftermarket product is the functional equivalent of the OEM product). I have seen some pretty convincing research from the BMW side that shows virtually no air-flow benefit to K & N filters over the OEM. Furthermore, the dirt trap studies found that the K & N filters were LESS effective than the OEM in trapping dirt. I would assume that Porsche's OEM filters are of comparable quality. Does anyone really think that Porsche would not supply K & N as stock if they felt they could get more hp without sacrificing filter efficiency? The cost would be truly minimal to them. I think it's very likely that Porsche could prove a K & N filter to be inferior in engine protection to the OEM in the event of a warranty dispute.