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Turbo Knocking??

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  #1  
Old 09-03-2008, 09:29 PM
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Default Turbo Knocking??

This was brought up a couple days ago but no one said much. My problem is that the first couple times cycling through the gears, when the turbo is spooling, there is a knocking noise coming only when the turbo is going, not at lower rpms or when idling... And it only does it the first couple of shifts... Any Help!???
 
  #2  
Old 09-04-2008, 10:56 AM
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turbos don't really knock.... bad motor mount and something is hitting the frame maybe? if it was a valve i woudl think that you woudl have it at low RPMs also but i may be wrong about that.
 
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Old 09-04-2008, 03:33 PM
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I have a similar issue. Though I'd say my noise is more like rattling/whinning/whizzing (sorry, hard to describe). It does it for the first couple minutes of driving, and then when it's warmed up, it doesn't do it any more.

Any other thoughts?
 
  #4  
Old 09-04-2008, 05:10 PM
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Yah I know turbos don't really knock and its just like you said it rccks96... It is just really bazaar why its only at the start... Another reason why it couldn't really be a valve or even motor mount... Really weird... Kinda worries if something is going bad... I guess I'll just have to get a new turbo!... Maybe KO4 upgrade while we're at it!... Just gotta explain that to the wife... Haha
 
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Old 09-04-2008, 07:13 PM
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I think you guys both have bad secondary air pumps, its a pump that injects air into the exhaust to heat up the cats upon cold start. Usually lasts about a minute or two then shuts off. If the bearings in the pump are bad it can sound like anything from a siren to a vacuum cleaner.
Take the belly pan off and dis-connect the electrical connector from the SAP pump and see if the noise goes away. This will create a check engine light though, it won't affect performance in any way.
 
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Old 09-04-2008, 10:14 PM
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But does that only come on when the turbo kicks in?

For me, the sound only comes on around 2,500 rpms, when the turbo starts to kick in.
 
  #7  
Old 09-05-2008, 01:04 AM
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You may have a bad turbo in that case, a blown turbo will commonly sound like a dentists drill or a police siren depending on whats wrong with the turbo. Are you still creating around 18 psi of boost with your APR chip?
 
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Old 09-05-2008, 01:48 PM
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Mine is the same situation... Just around 2500 when the turbo kicks in... And its only the first several running through the gears.. You an audi tech? Like at a dealership? I trust your judgement i just hope its nothing expensive... Oh yah and my engine is all stock...
 
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Old 09-05-2008, 02:00 PM
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I was an audi tech at the dealership. I would still try and disconnect the secondary air pump first and make sure thats not it.
 
  #10  
Old 09-14-2008, 11:07 AM
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Default knocking noise form turbo

my 04 makes the same knocking, clicking noise from the turbo. it only happens when i first start car and drive away right away. i thought it was a oil suppliy problem to turbo. i replaced turbo with new and also replace dv valve while it was removed. started car and same nosie. dont replace turbo for this noise!! expensive mistake. i am going to try to unplug the secondary air pump to see if noise is gone. although my pump works and sounds normal at idle does the boost over whelm pump? i will try removing fuse or unplugging pump. is there any other faulty valve responsible? thanks for your time!
 


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