What Are People's Views On K&n Air Filters?

[James.jerrum]

Not sure wether to get one are they even worth it

[iantt]

nope

[jeebowhite]

for the cost and the performance you get (a few horses, maybe up to 5) it gives you a bit more grunt, and as far as cost per horse is concerned, its cheap!

[Phil 87]

Also they save you money in the long run. Could be only 2x the cost of a normal filter and they only need to be cleaned every 3 years or so depending on mileage (you'll never need to replace it). I've got one that came with the Mountune upgrade, had a look at it before taking the car for a service and it still looked like new after 8 months of use.

[WES180]

Are you looking at replacement panel filter or an open cone induction kit?

[James.jerrum]

Panel filter. I have read reviews and it says they don't filter the air aswell as paper filters , and some. People have said that it lets crap into the engine

[jeebowhite]

the pores in the filter are slightly larger, but they are still very small.

The air filter is not there to remove all particles, its meant to stop debris getting in, throwing a leaf into the engine for example!

[James.jerrum]

Might try one then but do you have to use there cleaner or could you just use soapy water etc

[Phil 87]

Might try one then but do you have to use there cleaner or could you just use soapy water etc

I'm not sure if you can use soapy water, but there's some info here: http://www.knfilters.com/cleaning.htm

You won't have to worry about cleaning it for a long time though.

[TomsFocus]

My experience... Not worth the money, none of the aftermarket panels are even in cars I've had with 180bhp. You won't get anymore noticeable power and, as you're sticking with the original intake, no more noise either. The only advantage is that they can be cleaned...price will dictate whether it's worth it for that or not.

Also I'm not sure if your engine has a MAF sensor? If it does, there is evidence to show the K&N oil damages the MAF. K&N dispute this though, just wanted to make you aware.

[Phil 87]

My experience... Not worth the money, none of the aftermarket panels are even in cars I've had with 180bhp. You won't get anymore noticeable power and, as you're sticking with the original intake, no more noise either. The only advantage is that they can be cleaned...price will dictate whether it's worth it for that or not.

Also I'm not sure if your engine has a MAF sensor? If it does, there is evidence to show the K&N oil damages the MAF. K&N dispute this though, just wanted to make you aware.

Good point Tom, and I found some more info with a quick google. The 2nd post of the following thread has some good information, whether it's correct or not I don't know: http://www.benzworld.org/forums/w211-e-class/1267558-do-k-n-filters-really-damage.html

The thing I don't get is, why would Mountune include these filters in all of their upgrade packages and why would Ford support this with the warranty, if they are known to cause damage to the MAF sensor? Could it just be down to money i.e. Mountune have a contract with K&N, or could it be that Mountune and Ford both agree with K&N that it's just a rumour?

I wouldn't be surprised if it's true though, it reminds me of the tobacco companies doing everything they can to persuade people that smoking doesn't cause cancer, until the evidence was just to clear for them to deny it.

[iantt]

some diesels have maf sensors with oil on them without any issues,

£4ish for a normal filter, replaced every 3 years/37.5 k, how much is k&n ?and oil?

[Phil 87]

^ I thought the standard filters were more expensive, but if they're that cheap then I take back what I said about K&N filters saving money.

[TomsFocus]

I honestly couldn't say, I've personally never risked it on anything with a MAF after seeing many posts on various forums with MAF failures shortly after adding a K&N filter. Have only used dry foam filters with MAFs.

I have used K&N on cars without a MAF though so I'm not against them. There needs to be some independent study done to test the 'rumours' and prove either way I guess. It seems it's only K&N themselves who actively defend their brand...which isn't really helpful.

[iantt]

^ I thought the standard filters were more expensive, but if they're that cheap then I take back what I said about K&N filters saving money.

yes, thats from a motor factor, most people only keep there car 3years or so, used or new, so only need to buy one in there ownership. obviously pay more from ford.

only time to upgrade a filter for better air flow is when modififying engine fueling/turbo/ign characteristics that enable higher maf g/s

[jeebowhite]

some swear by the idea of just replacing the paper filter every 3 - 6 months to get the maximum benefit

[James.jerrum]

What's that sensor thing for the filters

[Phil 87]

Isn't the MAF sensor easy to remove? I'd be interested to have a look at mine to see if there is any residue building up on it, but I certainly haven't noticed any problems. Would there be any fault codes / warning lights if the sensor was reading incorrectly?

[jeebowhite]

Yeah it's pretty easy. Disconnect the mass air flow hose, remove them out the way, unscrew and done.

[TomsFocus]

MAFs usually don't bring up fault codes due to the way they work. The best test for an old MAF is to unplug it - if the engine performs better or no different then the MAF is failing, it's either reading too low or not reading at all so the ECU uses 'safe' settings. If the engine loses power the MAF is good.

I don't know if that's still the case on new cars though!

As James says it's an easy part to remove and look at.

[Phil 87]

Here's some more info I found: http://www.nicoclub.com/archives/kn-vs-oem-filter.html

You can see why the K&N filter is known as a "performance" part when you look at how little it restricts the air flow. I just hope all these particles it lets through won't cause any problems.

[MattDRX]

Most of the debris will get clogged in the inlet before it gets into the chambers anyway, take any inlet off a car and wipe the inside with your finger, they get covered in crap that gets past the airfilters over time.

Fords price was £7 for the standard filter when I asked a while back.

The K&N Typhoon kit is meant to be quite good, bit pricey but still less than some of the other cheap looking crap the likes of Mountune and Pumaspeed "recommend" or have been Bribed to use as I put it.

Just make sure you put the sticker on the airbox, come service time they have a habit of whipping it out and sticking a standard one in there. they must also be oiled at all times, otherwise it's degrade and the car will eat it and give you molten plastic stuck to the inside of the engine, same as some ITB filter issues when they aren't oiled.

[troy45]

With the Focus ST Ford gave the K&N panel their seal of approval by it being part of the Mountune MT260 upgrade package, which maintains Ford's warranty on the car. Or did while they were new enough to be in warranty.