Chris NottEM Tuning
Results 1 to 17 of 17
  1. #1
    imported_alecblack
    Guest

    Fluttering noise when lifting off accelarator

    Can anyone tell me if this sound is meant to be there? I have a 1.8Turbo and when i am driving and lift my foot off the accelarator pedal i hear a light fluttering noise.

    Is this normal or does it sound broke?

    Its my first turbo car and im not sure if it is the turbo spinning or something worse.

  2. # ADS
    ADS
     
  3. #2
    imported_gek
    Guest

    Re: Fluttering noise when lifting off accelarator

    I think it means your DV is knackered.

  4. #3
    Grant's Avatar
    5th Gear

    Status
    Online
    Join Date
    Dec 2003
    Location
    Aberdeen
    Posts
    1,116

    Re: Fluttering noise when lifting off accelarator

    Sounds like your diverter valve is knackered - common problem with OEM valve... they don't last that long.

    A new one will cost about 25 from Audi.

  5. #4
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2003
    Location
    Surrey
    Posts
    469

    Re: Fluttering noise when lifting off accelarator

    Yeah, agree - I noticed mine when I could hear turbo fluttering between gear changes. A new one should mean you lose the fluttering sound and get smoother gear changes as turbo pressure will be maintained instead of being lost when lifting off/changing.

  6. #5
    imported_alecblack
    Guest

    Re: Fluttering noise when lifting off accelarator

    This has been happening since i bought my car 5 months ago, is this a serious problem, is it costly to fix, does it affect the performance.

    Sorry for the barage of questions but im a bit worried now.

  7. #6
    2nd Gear

    Status
    Offline
    Join Date
    Apr 2003
    Location
    s.wales
    Posts
    363

    Re: Fluttering noise when lifting off accelarator

    I thought the fluttering noise is the turbo stalling because the air being forced into the engine hasw knowhere to go ( up against a closed throttle ). Probably won't damage yours but on bigger turbo cars with high boost can shatter blades.

    Chris.

  8. #7
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2003
    Location
    Surrey
    Posts
    469

    Re: Fluttering noise when lifting off accelarator

    Hmm, not sure: are you saying that because the valve starts leaking, it fails to open and divert pressure, thus keeping turbo pressure too high in the engine?
    Could be - anyone else want to chip in as to whether this can cause damage?

  9. #8
    imported_alecblack
    Guest

    Re: Fluttering noise when lifting off accelarator

    Would it be worth my while getting an uprated one. I am probably not planning on chipping it in the future, at most a K&N and a back box

    Is there any bhp increase in an uprated one? Or any other benefit.

  10. #9
    2nd Gear

    Status
    Offline
    Join Date
    Apr 2003
    Location
    s.wales
    Posts
    363

    Re: Fluttering noise when lifting off accelarator

    Fluttering is def the turbo stalling. On low boost cars there probably won't be a problem though its not ideal. Fitted the forge valve myself and found it to be weaker than the standard one. Phoned forge and they sent me their 'yellow' spring. Def felt more responsive. But mine is a mapped S3. Not sure it would make a difference on regular boost.

    Chris.

  11. #10
    imported_Stewart
    Guest

    Re: Fluttering noise when lifting off accelarator

    s3bow, if yours is mapped and running at least 1.1bar ish (bout 15-16psi at least) then i would try the blue or even the red spring.

  12. #11
    HTC
    HTC's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Jan 2004
    Location
    Koh Samui, Thailand
    Posts
    3,402

    Re: Fluttering noise when lifting off accelarator

    s3bow, just to let you know, the fluttering sound is not the turbo stalling. Its the sound of the air through the faulty diverter.

  13. #12
    2nd Gear

    Status
    Offline
    Join Date
    Apr 2003
    Location
    s.wales
    Posts
    363

    Re: Fluttering noise when lifting off accelarator

    Which one do you have ?

    Chris.

  14. #13
    HTC
    HTC's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Jan 2004
    Location
    Koh Samui, Thailand
    Posts
    3,402

    Re: Fluttering noise when lifting off accelarator

    The valve is a plastic rubber diaphram. The diaphram can tear. It then leaks and flaps about as the air passes it.

    The throttle response issue is due to the valve inability to hold boost correctly when requested.

    Turbos stall when the pressure in the inlet track exceeds the force the rotors can supply. For example if the throttle flap is closed and the DV stays shut pressurising the area between the turbo and throttle body. This can happen, but if it is fluttering then it will be the torn DV.
    Turbo stalling is much louder.

  15. #14
    2nd Gear

    Status
    Offline
    Join Date
    Apr 2003
    Location
    s.wales
    Posts
    363

    Re: Fluttering noise when lifting off accelarator

    I stand corrected .

    Chris.

  16. #15
    imported_Gibbsy
    Guest

    Re: Fluttering noise when lifting off accelarator

    I must say i disagree with most of what is said as i had this problem a while ago, bought a new DV from VAG parts, fitted it and the sound is still there.

    Now correct me if i'm wrong but surely it wont break as soon as i start the car.

  17. #16
    Reverse Gear

    Status
    Offline
    Join Date
    Dec 2004
    Location
    S.WALES
    Posts
    12

    Re: Fluttering noise when lifting off accelarator

    I thought the chattering was just the noise of the waist gate, heard mine more when i fitted an ITG pannel filter...

    I thought they were suposed to make that sound...It is it's job

  18. #17
    HTC
    HTC's Avatar
    6th Gear

    Status
    Offline
    Join Date
    Jan 2004
    Location
    Koh Samui, Thailand
    Posts
    3,402

    Re: Fluttering noise when lifting off accelarator

    [ QUOTE ]
    I must say i disagree with most of what is said as i had this problem a while ago, bought a new DV from VAG parts, fitted it and the sound is still there.

    Now correct me if i'm wrong but surely it wont break as soon as i start the car.

    [/ QUOTE ]

    Its difficult to diagnose turbo noises on the net. You may have had anything from a boost leak to a faulty N75?
    Generally its the DV, but obviously there are exceptions.

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO