RE: S4 Wastgate noise

[Peter Henriksen <peterhe@microsoft.com>]

I'm the one who did the bypass valve (not for $45, though. More like
$100...). Could be related to why I'm hearing it now. The hose Mike
mentions is already rerouted along the firewall, the passenger's side
wheel and then the front down to the bypass valve.
- peter
  peterhe@microsoft.com - http://www.geocities.com/MotorCity/1001
  91 200qw
  94 acura legend gs
  issaquah, wa, usa


>-----Original Message-----
>From:	Mike  [SMTP:JoMi@msn.com]
>Sent:	Wednesday, November 20, 1996 12:59 PM
>To:	quattro@coimbra.ans.net; Tim Miller
>Subject:	RE: S4 Wastgate noise
>
>Sounds to me like the turbo bypass valve is opening, dumping boost as it 
>should. If the noise is new/getting louder, perhaps the bypass valve is 
>opening sooner. I think the 92 S4 has enuf similarity to the 91 3B engine for
>the following. Check the hose that runs from the back of the Intake Manifold 
>to the turbo bypass valve for leaks or being crimped where it comes out of
>the 
>IM - there is a bracket there that the hose runs overs that is not the best 
>design in the world allowing the hose to pinch. The cost of a new wastegate 
>from the Dealer is ~$900. There are places that rebuild them for ~$300. 
>Swapping a WG takes well under 1/2 hour - dealer labor is around 2 hrs as I 
>recall. The WG is really very simple inside and not at all difficult to take 
>apart.  The bottom seat should be floating. Mine with 75k miles had a worn 
>valve guide and crudded up valve stem. I cleaned the crud off the stem and 
>touched it up with some 400 grit and it moves much more freely. Could be the 
>bypass valve is bad - Peter just replaced one for ~$45 as I recall. Are you 
>still seeing full boost? Send me private Email if you want detailed 
>instructions for pulling the WG - it's only 7 nuts to remove.
>
>mike miller
>91 200q
>
>----------
>From: 	owner-quattro@coimbra.ans.net on behalf of Tim Miller
>Sent: 	Tuesday, November 19, 1996 8:51 PM
>To: 	quattro@coimbra.ans.net
>Subject: 	S4 Wastgate noise
>
>
>I have a 92 S4 with 52k miles on it.  Lately there has been a noise coming
>from the engine when I let off the gas pedal after hard acceleration.  Over
>the past few thousand miles this noise has been getting louder and occuring
>more often.  The dealer told me that it was coming from the wastgate and this
>is normal.   I do not like the sound and I don't feel that it is normal. 
>After the turbo winds up and I decrease power is when the noise occurs.  The
>noise can best be described as a wheezing, discuss type sound.    Does anyone
>have a similiar problem?  Is replacing the wastgate an expensive job?  Any
>help is greatly appreciated.
>
>Tim Miller
>92 S4 TAP Chip
>
>
>