[s-cars] Boost leak - update, what am I missing here?

chris chambers fastscirocco_2000 at yahoo.com
Sat Apr 21 17:40:27 EDT 2007


I second the suggestion that you may have a bad WGFV (or failing)

What type of boost gauge do you have, is it possible the gauge is
failing and you've convinced yourself you have lost power? You might
want to consider borrowing a gauge from someone to test.

Where does your gauge hook up to read boost? Perhaps the problem
lies there??

Where are you located? With my S4 down for now I'll be glad to
loan you any parts you need that might help you diagnose this.
My car has a new WGFV on it (and other parts), and I'm in Kalamazoo
MI and get to the Toledo/Sylvania OH area every week.


--- Mike Claire <mike.claire at gmail.com> wrote:

> A bunch of you guys replied to me last week with ideas, and I
> appreciate the
> help.  I've gone through everything suggested, and have read
> everything
> about these issues I could find on Scott Mockrey's site,and STFA with
> abandon.  I'm pretty much tapped - nothing to show for it.  I was
> distracted
> this week by new symptoms - and ultimately #3 coil just failed
> entirely.
> Dead short.  That's fixed now and the car runs great again - except
> it's
> still low on boost.
> (subject is a '93 S4, MTM 1+ (Pastore) chip.  Used to indicate 22 lbs
> on
> A-pillar gauge.  Now it peaks at 16 or 17, and backs down from
> there.)
> I'm either losing boost - or not making enough of it.  I don't know
> where
> else to look - what am I missing here?
> 1.  Pressure tested main intake plenum to 15 lbs with a compressor
> and PVC
> cleanout plugged into the intake boost.  Closed off Samco where it
> enters
> the intake, and the ISV - PASSED
> 2.  Pressure tested all the small hoses in the PCV circuit, water
> trap, ECU
> connection, boost gauge connection, etc. etc.  PASSED
> 3.  Removed BPV, plugged the Samco, plugged vacuum line (eliminate
> possibility of BPV leaking pressure).   PASSED
> 4.  Removed silicone line from wastegate, plugged it shut (to test
> for
> possibility of wastegate opening prematurely)  PASSED
> I can only think of two possibilities - either the turbo is no longer
> capable of building normal boost, or the intake plenum is leaking at
> pressures higher than 15 lbs.
> Could the turbo be failing?  It sounds the same and drives the same
> as ever
> I can take the Samco off the turbo outlet and pressure test from
> there, but
> I don't have compressor plug handy for that.
> Before I do that - any ideas?
> Mike
> _______________________________________________
> S-CAR-List mailing list
> S-CAR-List at audifans.com
> http://www.audifans.com/mailman/listinfo/s-car-list

Make April 15th just another day http://www.fairtax.org

Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 

More information about the S-CAR-List mailing list