HELP!! What is this noise?

Quattro180

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click on the picture below and listen to the strange noise coming from the air intake. I am sure that something is wrong with it? Any ideas????



cheers
 
chicken flu ?
 
mine does exactly the same, i havnt fully investigated it yet but suspect iether a split intercooler or the metal pipe that connects them at the bottom. sounds almost like intercooler pipework is pressurising and maybe a split is opening up and sucking in air when a ceertain pressure is reached.Anyone else ever heard this before?
 
Surge generally refers to a condition where airflow moves backwards in the compressor, whether in an axial flow compressor (blade tip stalling) or a centrifugal compressor. (ie: turbocharger).
Airflow moving in two directions during surging "crashes" inside the compressor and can stall the compressor, cause mechanical damage, or in a small surge disrupt the operation/speed of the compressor momentarily.

Turbocharger - Wikipedia, the free encyclopedia
 
Please do i would get mine into a garage to had someone not tried to park a rangerover on it last week. its in the body shop at the mo. I would be very keen to hear the results as compressor surge sounds like code for you need a new turbo.
 
has anyone had any look with finding out what this is as mine is doing the exact same thing and its raly annoying lol
 
I asked an Audi mechanic and he said that some of the cars make this noise and some don't!! I am still not convinced tho. I also got vag plugged in and cleared a mass air flow meter fault and the noise isn't so bad now. This fault was caused when I took the air flow pipes apart and started the engine. My mpg is around 33-35 mpg aswell which is about right.
 
i would have said its turbo related, it only happens when you come off the throttle so as has been suggested above i would suspect compressor surge.

Im not sure how TDIs work but the petrol 1.8T have a valve between the turbo and the intake manifold which when you come off the throttle relieves the back pressure and stops compressor surge/stall. If turbo diesels work the same then it may be just a case of getting this valve checked.
 
thats what i mean when i say i dont know how TDIs work, i dont know if they have a DV
 
so if there is no dump valve what is there to stop compressor surge because i dont think these engines do this as normal. Am i right in thinking that a diesel doesnt suffer from this as there is no throttle flap like a petrol engine. There is as said above a flap inside the egr valve. Any diesel experts about?
 
no d.v ud think there was with that noise lol its realy anoyin mine never did ths when i first got my b6 butafter taking intake parts apart for cleaning ive had the very same noise ive cleaned egr so dont think its to do with it being clogged would love tknow where to begin to eliminate this even if it was trial and error. will it not log on vag com?
 
leak in the intake????? as u just said started after you messed with that area?????
 
had car on vag com no fualt there to suggest anything also cheacked fo obious leaks but all looked ok after a good mess around though it can only be dcribed as when reved sems abit restrictive on thesuck of air in and once let off the peddel air seems to flw back to the air filter box and blow out there making that noise so def seems like restriction or blockage somewhere any more thoughts guys? or anyone elsewith this problem fixed it yet?
 
I believe i have stopped the noise now from happening it certainly doesnt do it now, i was having a hesitation when it came on boost and was trying to fix it, i fitted a blanking plate to the egr to remove it from the system to see if this was the cause of the boost issue and low and behold the noise has stopped as in the video and i no longer have the hesitation either, so my guess is that it is being caused by the egr valve possibly the flap inside it isnt closing fully so there is air getting through when it should be closed. I havnt taken it off all i have done is to fit a plate to the egr valve itself at the front of the car side of it, you will see when you look. A friend gave me a plate a while ago but you could make one out of a piece of flat steel or stainless, just remove the pipe that goes between the egr and the intake manifold and draw around it as a template, it wont cost anything to do really apart from an hour of your time.
 
Noticed your post on this,
could you post some pictures for all us 2.5 owners re a how to block EGR valve please.

Thanks.

I believe i have stopped the noise now from happening it certainly doesnt do it now, i was having a hesitation when it came on boost and was trying to fix it, i fitted a blanking plate to the egr to remove it from the system to see if this was the cause of the boost issue and low and behold the noise has stopped as in the video and i no longer have the hesitation either, so my guess is that it is being caused by the egr valve possibly the flap inside it isnt closing fully so there is air getting through when it should be closed. I havnt taken it off all i have done is to fit a plate to the egr valve itself at the front of the car side of it, you will see when you look. A friend gave me a plate a while ago but you could make one out of a piece of flat steel or stainless, just remove the pipe that goes between the egr and the intake manifold and draw around it as a template, it wont cost anything to do really apart from an hour of your time.
 
will do. here is a photo of the plate insitu, its the silver band you see inbetween the egr and the pipe. Im thinking i should remove the vacuum pipe from the top of it and block it as at the moment im sure it will still be operating but there will be no gasses passing through
feel free anyone to comment.
egrblank.jpg
 
Last edited:
Hi all... Would just like to share and confirm some info... The noise is defo something to do with the egr system... My 2004 v6 started making the same noise after blowing an intercooler... I had to drive the car home with it chucking serious amounts of black smoke:-( I removed the egr and gave it a real good clean, car felt better but still sneezing on gear change:-( this morning knocked up a quick blanking plate and BINGO!!! No noise at all, back to the fast, quiet! Car that I'm used to:)) no warning lights and much happier knowing I'm not chucking dirty exhaust fumes back through my engine!!
 

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