K & N Filter Hell

[s2munckton]

Hi All,

Just thought I would share the issues that I have been having and the incredibly easy solution that seems to have fixed all my problems.

For the last few months the S2 has steadily been getting more temperamental; the fuel consumption has gone through the roof, it has been stalling when at idle, dumping the boost and I have been getting numerous fault codes including.

00544 – Maximum boost pressure exceeded
27-10 – Implausible signal
00537 – Lambda regulation
11-10 – Control limit not reached – intermittent
00561 – Mixture adaptation
13-00 –Adaptation limit (Mul) not reached
00513 – Engine Speed Sensor (g28)
03-00 – No signal

I had tried several things including replacing the various sensors and cleaning the MAF. When I cleaned the MAF, things seemed to get better for a short period and then it would go to hell again. I was chatting to a mate about it and he asked if I had a paper filter or an oil based filter. Since I have had the car I have been using a K&N filter which I was cleaning and oiling once every 8 months or so.

He suggested that the induction might be forcing the oil out of the K&N filter and onto the hot wire of the MAF and that I should try a paper filter. I changed the filter to a paper one (WESFIL) and it seems to have sorted out all of the problems (gave the MAF a clean as well). The car is now pulling cleanly in every gear, the idle is smooth and although I don’t have vagcom to check the fault codes, I have no reason to believe that there will be any.

Unfortunately, there is a slight trade off. I no longer have the fantastic induction noise when on boost and I have lost a couple of HP.

I am sure there must be performance dry filters out there for the S2, can anyone recommend one? Or perhaps a pod filter kit that can be bolted onto the MAF?

Anyway,

I hope that someone else finds this useful.

Signed,
One Happy Camper!

[sheppardnias]

This is a well known fault amongst those of us who have VAG diesels. It's also a fault that K&N denies the existence of.

I have run cars with and without K&N filters of both panel elements and induction kit types and I can't say I ever notice any benefits from them. They are noisier and that is usually a good thing but they can be more hassle than they are worth.

I think that the one of the main problems can actually be over cleaning and oiling of the elements. Its easy to say how much oil they should be sprayed with but another to ensure that you apply that amount.

After years of fiddling with them I have settled on the approach of removing any K&N style filter from a car running a MAF with a hot wire. This includes removing it from my URS6, my Passat and my Skoda. All of them have had problems with a dirty oily build up on the MAF at one time or another whilst fitted with non standard elements. The only thing I now have on an induction kit is my Cobra and that suffers no problems at all, largely because it never moves out of the garage......

[Fat Audi 80]

I totally agree. Touch wood, I have never experienced those sort of running problems in my S2, but have only ever put OEM Paper Air Filters in it, same for the previous owner.

I think Oiled K&N's are for Escort's and Nova's! (IVHO)

Glad to hear you have sorted it out.

Cheers,

Steve.

[Error404]

very similar problem to a mate of mine had with his S14, which uses the same type of AFM - we swapped it to an Apexi cone filter
becasue they flow very well indeed, and don't need oil and will not **** up your AFM. They are also the best filtration amongst all the major filter mftrs. Not sure about neck sizes on them, one will work for you.
FYI - the one we put on his S14 was smaller than the K&N and flowed enough for over 400bhp

Speak to Phil at Driftworks, tell him Alex from Kings Heath sent you, he'll sort you out -

HTH
Alex

[re2500]

It makes sense that actually. the oil being sucked out of the filter.
Ive always found pipercross foam filters to be quite good. you dont need to oil those. JUst clean them in soapy water dry and refit. I might discard the K&N and try a pipercross, see whether it is hassle free.
Anybody on here got a pipercross filter?

[Bram]

Will the MAF not burn off any dust or oil from the MAF wire at starting?

I have currently a K&N filter fitted in my airbox and I run a GT3071R turbo. I will give it a try with a paper filter and tell you if I noticed any difference. I have no fault codes BTW

[Error404]

Pipercross filters DO need oiling AFAIK - at least they did last tie i bought one a few years ago now

[Rusty]

Sounds like you've over-oiled the filter, it warns against this in the cleaning instructions. I use paper towel to remove excess oil from the filter once it's oiled. No probs in 4 years...

[Error404]

anyway, K&N are to filters what McDonalds are to food - cheap *****

[Rusty]

[HPmuirt]

If you want more noise, fit an RS2 airbox with an OEM paper element. Makes a good noise without being too Orificer Casey like (Chavvy )

Cheers n

Si

[Error404]

i like chavvy noise



EDIT: and i don't mean bassline house BTW

[Rusty]

i like chavvy noise

Cut the front off your airbox then, chavs up the induction noise a treat!

Cone filters are proper chavvy, my 'modified' airbox is... erm... Officer like

Si, you getting that sense of déjà vu here?!

[S2central.net]

This ain't new unfort - needs to better documented though...

As said already - an over oiled filter can give your MAF some grief. Yes the MAF does have a burn-off signal to clean any contaminants of the hotwire, but this is only done once for a brief pulse after shutdown... If you are driving continually with oil vapour munging up your MAF then its ability to clean by the burnoff signal will gradually reduce.

You can indeed try the Apexi of PiperX filters, but I am also of the new paper brigade every service. And yes the RS2 airbox makes a difference - or carve out larger openings in the ABY one.


Paul

[Rusty]

I'm going to drill the cold side of mine when I'm better... worked a treat on a few old Golfs, 20mm holes sounded pretty good, so should make the induction purr more of a roar