K&n Filter Noise

[T2Andy]

After fitting the RS2 Airbox with supplied K&N filter the noise from the wastegate \turbo
has dramaticly increased .It makes a dump valve type noice even on slight throttle and no boost is this the norm ,it sounds like DARTH VADER has moved in to the air box.It has made the car sound like your typicle scooby.The cars running ***** at the mo
so i think the maf could be oiled up.

[terrybullwon]

Sounds right, i have a cone on and makes same sort of noises.
Must say nothing like a scooby, they just sound like a beatle with a turbo straped on

[T2Andy]

[A80Avant]

Κ/Ν as it allows more air and it is less restriction of the incoming air,you do seem to hear the turbo build up.I dont think it has anything to do with the dump valve though.

If the car is running shitte,then yes probably the maf.It may also develop unstable idle as well

[Rusty]

My airbox with no front on it sounds fairly loud and gives a much louder dump valve sound than a standard one. I have noticed a dump valve hiss noise when letting off at any boost over atmospheric (obviously). Off boost, mine sounds like a golf with a drilled airbox. Wicked! Cone filter sounded great on full boost but was crap at cruise, giving a horid farting noise when boost was approximately atmosphere. Got rid of that quite quickly although I might use it for a track day.

My arguement would be that as there's less restiction going in, there's less restriction to nise getting out! All part of the fun I suppose.

If you're genuinely worried something's wrong then maybe a new diverter valve or an overhaul if you have a Forge etc. might help? Or put the box on someone else's car and see what it sounds like / listen to someone who's got one.

[T2Andy]

Im not to worried that something may be amiss but it just seemed very loud compared to normal .my idle has been all over the place until warm but it still jumps and drops when
pulling up.cleaned out the isv last night so i will see what happens.will clean the MAF today.There has also been some hesitation when giving it some through the gears
esspecialy at 4\5k .

[Rusty]

My Lambda sensor made a real difference to the smoothness of the engine. Not a bad bet if you've never replaced it, about £65 from VAG Parts. Simple job too, just take off the airbox and it's there in front of you! Car was showing an active mapping error on Mihnea's laptop and that convinced me that the lambda was knackered. Checking for codes or errors would be a good plan, if you haven'yt already done so. Might highlight something.

Is the boost gauge fluctuating at all? Could be a leaking DV, might make some funny noises?

S3 DV and a Lambda probe might be a good plan, sorted a few niggles out on mine very nicely.

I'm suprised that Jamo, Hpmuirt and Newsh haven't commeneted as they were all running RS2 airboxes.

[Ski]

when i had a box and fitted a KnN filter I had the same noise.

[s2dude]

My Lambda sensor made a real difference to the smoothness of the engine. Not a bad bet if you've never replaced it, about £65 from VAG Parts. Simple job too, just take off the airbox and it's there in front of you! Car was showing an active mapping error on Mihnea's laptop and that convinced me that the lambda was knackered. Checking for codes or errors would be a good plan, if you haven'yt already done so. Might highlight something.

Is the boost gauge fluctuating at all? Could be a leaking DV, might make some funny noises?

S3 DV and a Lambda probe might be a good plan, sorted a few niggles out on mine very nicely.

I'm suprised that Jamo, Hpmuirt and Newsh haven't commeneted as they were all running RS2 airboxes.

By far the best pace to buy a lambda is ebay or
justlambda http://www.lambdasensor.com/main/muniversal.htm

A lambda is a lambda. and these are all bosch also.

edit// i got a new Bosch one off fleabay for £35 delivered

[Jamo]

Yeah you can hear the noise on dump, it's the back draft of air as i'm lead to believe the DV is a restriction in this respect.

On S2dudes site post the part numbers are

Model Year Bosch Tomco Universal
80 2.2 S2 Quattro ABY 02/93-01/96 0258003957 11363 11983
80 2.2 RS2 Quattro Avant Estate ADU 03/94-05/95 0258003957 11363 11983

listed @ £62.28

But this is interesting for diagnositcs only

http://www.lambdasensor.com/main/mwide.htm

BTW GSF sell the lambda @ around £35 plus vat

[alg]

Was the car running OK pre RS2 airbox/K&N ?

If so think oil contamination from K&N filter and clean as planned.

If doing this before switch then the usual culprits come to mind as listed above with boost leak top of list to check ( with attention to MAF/airbox connection if problems after fitting)
Lambda does not always fault code and would be worth doing if not done before. IIRC should not cause problems with WOT @5k.
Finally DV have a finite life but usually tell you if they are dead with telltale noise.

Must admit that having played around with K&N on my S2 I would always recommend sticking with OEM and change 1-2/year depending on how much city driving you do.

[newsh]

I like the Darth Vader sighing noise, its not too extreme

[T2Andy]

well ive just cleaned the maf and grilles and were quite sutty and the car ticks over
perfectly but that could be the ISV i cleaned last night ,took her for a run up the bypass
and it didnt miss a beat up to red line in 3rd and 4th so all seems well at the mo.
Had new lambder a few months ago .cheers,

[Jas11n]

Does it sound like this? >>> Strange noise

Sorry Andy, just had to post it
(not my find either, Karlos (bibby) found it and posted on fans)

[topsparky]

Does it sound like this? >>> Strange noise

Sorry Andy, just had to post it
(not my find either, Karlos (bibby) found it and posted on fans)

that's so funny jase
wonder it they'll do a group buy