[200q20v] Low boost (1.7) and Hesitation under load (4000 rpm+)

Noelle Beaudin nobeau at tcnow.com
Mon Sep 3 15:39:26 EDT 2001

Hi Shawn and listers,

Shawn wrote:
>Problem number one: I recently replaced the Turbo Bypass Valve. I did not
>notice a boost drop right away, but after a few weeks I realized that I was
>no longer able to get the 1.9 & 1.8 bar now the maximum boost is 1.7 bar and
>it is as though that is getting harder and harder to get.
>Problem number two: I am also experiencing some hesitation under load while
>accelerating. There just is not as much happening under the hood as there
>should be. Acceleration above 4000 rpm is half of what it should be.
>I think my gas mileage has drooped, but cannot verify it. 85mph 18-18.5 mpg?

Then I wrote that I have the same problem. 

After a wondrerful Bank Holiday weekend of work on said Audi, here is 
what I found:

1. Went through SJM's checklist of "The ABC's of Running High Boost..."
2. Everything checked out except the turbo bypass valve which I 
removed.  Blew through it, sure enough, air was coming out.
3.  Replaced it with part ordered from Blau.
4. Cleaned all knock sensor wires and connectors.
5. Wha-la!  Both problems fixed.

Goose is running like a charm now.


More information about the 200q20v mailing list