HELP..Possible Air Filter problem

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
Hi Guys

ive quite recently changed my air filter for a pipercross panel filter and unless its just coincidedence of some other failing part, it seems the car just is not liking it at times.

Every now and then it really holds back when you let the car boost at all ..
(but a smooth hold back if you get what i mean, like the the pressure from the turbo is being blocked or something:confused:)

The gauge will read 1.2 bar but nothing happens and there is no external leak sound either whilst its on boost,
but it does make a strange loudish pisstt when you come off the accerator

ohh and i should add it was re-mapped with the standard filter in originally, and the weather has turned fairly cold since so maybe thats it..

hope this makes some kinda sence :D

Any suggestions please would be great guys

cheers
 
Last edited:

Gooner_Mike

Teaching the kids
Jan 20, 2008
4,363
2
Hampshire
www.facebook.com
The loud noise when you come off the accelerator will be the diverter valve dumping air back into the intake (doing what it is supossed to do). You are just hearing it more with the new filter probably. As for the boost problem it is probably an issue with the remap!
 

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
As quoted by Gooner Mike: The loud noise when you come off the accelerator will be the diverter valve dumping air back into the intake (doing what it is supossed to do). You are just hearing it more with the new filter probably. As for the boost problem it is probably an issue with the remap!

yeah i muchly appreciate the reply matey, but i dont think its what youve suggested and the remap worked fine before the new filter :(

I know these engines fairly well and how they function, because when its running ok it makes a very faint dumping sound from the dv (still louder than before the std filter) but its not that type of noise if you get what i mean... to be honest i think it could be worth me putting the std filter back on and see if it cures it.


Could be the maf as suggested because of the increased metered air flow into the engine but this was only replaced early last year.

Any more suggestions would be greatfully received.

Thanks
 
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traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
as said the map hasnt changed by itself, cant see it being that.

id try unplugging the maf and see if it runs better, they can fail at any time.
you could try disconnecting the battery as this will reset the ecu. clean slate so to speak.

other than that its tracking down someone with vagcom to check for faults or logging various parametres hoping the fault shows up.
 

Willie

LCR Track car
Aug 6, 2004
8,939
1
Sunny Scotland
Change back the filter and if that solves it then you have your problem.
Would doubt it is but you don't know till you try.
Are you sure everything is tightened up with no boost leaks
 

sambryant

RoadRunner meep meep
Mar 26, 2009
4,848
2
Bristol
what dumpvalve have you got?
if you have the split r one by forge you will have to reset it. it sound to me like boost leak. i had this with mine when i added a cone filter.
 

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
what dumpvalve have you got?
if you have the split r one by forge you will have to reset it. it sound to me like boost leak. i had this with mine when i added a cone filter.

My car has always ran a std dv, before and after the re-map but that has been off and checked for leaks and thats fine..

i wish their was a audiable leak so i could solve the problem but their isnt:(
 

sambryant

RoadRunner meep meep
Mar 26, 2009
4,848
2
Bristol
forgot to say, changing the airfilter effects the dumpvalve. i really would say you spring in your dumpvalve needs to be stiffer. (holds the boost more) other wise air pressure is going through the dv back into the air intake when using throttle. you wouldnt always hear this.
 

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
forgot to say, changing the airfilter effects the dumpvalve. i really would say you spring in your dumpvalve needs to be stiffer. (holds the boost more) other wise air pressure is going through the dv back into the air intake when using throttle. you wouldnt always hear this.

That could well be my answer good man, had not thought of that,

but today i have reset throttle body (also cleaned it) and replaced the last coil pack that was getting old and it seems to be ok again (touch wood) but it still seems as though its quite not going as well as before so it could well be dv leaking slightly under high boost.

just need to find a kind man to sell me one cheap as funds are not great at the moment, we'll see later after ive been to birmingham this weekend hopefully with no probs along the way..

cheers
 

traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
forgot to say, changing the airfilter effects the dumpvalve. i really would say you spring in your dumpvalve needs to be stiffer. (holds the boost more) other wise air pressure is going through the dv back into the air intake when using throttle. you wouldnt always hear this.

how does the air filter affect the dv?

Stock dv if in good condition should be fine.
 

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
as said the map hasnt changed by itself, cant see it being that.

id try unplugging the maf and see if it runs better, they can fail at any time.
you could try disconnecting the battery as this will reset the ecu. clean slate so to speak.

other than that its tracking down someone with vagcom to check for faults or logging various parametres hoping the fault shows up.

Cheers for your advice,

i have a friend with vag-com and he should be doing some checks with my car soon hopefully when he gets a moment, so there could also be fault elsewhere possibly

I might also disconnect battery/reset ecu in the meantime to see if that irons out any probs..

cheers again.
 

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
how does the air filter affect the dv?

Stock dv if in good condition should be fine.

i did wonder that, the guy who did the remap said as long as the dv is in good health it should be fine but im starting to wonder who to beleve without stepping on anybodys toes lol
 
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traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
The stock dvs rubber diaphram will eventually perish as it ages. But it should be strong enough if in good nick.

The reason many change to forge or similar is they have no rubber to fail over time. it uses an alloy piston that cant tear... but they do need a quick yearly service otherwise can stick.:)
 

shauncupra

Active Member
Jun 19, 2007
59
0
Norwich,Norfolk
The stock dvs rubber diaphram will eventually perish as it ages. But it should be strong enough if in good nick.

The reason many change to forge or similar is they have no rubber to fail over time. it uses an alloy piston that cant tear... but they do need a quick yearly service otherwise can stick.:)

cheers for that,

i will get a forge one soon hopefully just to rule out possible probs:)
 

sambryant

RoadRunner meep meep
Mar 26, 2009
4,848
2
Bristol
how does the air filter affect the dv?

Stock dv if in good condition should be fine.

with cone filer for example. it allows the turbo to spool up much quicker. this puts the dv under more strain,
the standard dv are known for failing, also what u have to remember this guy is using a standard dv on a mapped car (not good) forgive me if im wrong but im sure he needs to run a yellow spring.
 
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