Chasing Vacuum Leaks

Larry C. Leung l.leung@juno.com
Tue, 20 May 2003 20:36:03 -0700


Nick,

Well, you were right on the money. I had decided to replace my IC with a
spare
good one I had and I ended up with a perfect birds-eye  view. Crack on
the
belows. It doesn't feel like it's all the way through (although there is
an oil
weep) but nonetheless, it's time for a new one. That plus the "Tee"
breather
hose and hopefully this will all be tied up. Also found the clamp to the
hose
from the Turbo to the intake was a little loose. A whole lot of little
things....

Thanks, list,  for all of your help


LL - NY


On Mon, 19 May 2003 10:07:37 -0400 "Nick Lawrence" <nick@beol.net>
writes:
> Here is an idea that I have experienced.
> Some cars have a two piece hose from the the turbo to the
> intercooler, some
> have one. If one it's a "J" shape. My '90tqa has a two piece, the
> upper
> section is a rubber bellows about 3" tall.  It leaked under
> pressure, not
> vacuum.  Laying on the ground under the front end, reach up to feel
> this
> hose on the top side of the bellows, push on the creases with some
> vigor and
> you might find a crack. I've bought two recently for about $30 ea. I
>  think
> I got them from  Audi dealer, Thoroughbred Motorcars in Tenn. Don't
> have the
> number here but I think you can find them on the web, or one of the
> other
> cooperating dealers.
> Nick
> On another car we tried pressurizing the intake to chase leaks and
> could
> hear but never was able to pinpoint or determine if it was real, (on
> a 20v).
> ----- Original Message -----
> From: <l.leung@juno.com>
> To: <quattro@audifans.com>
> Sent: Monday, May 19, 2003 9:05 AM
> Subject: Re: Chasing Vacuum Leaks
>
>
>
> Patient (as I'm not...anymore) '89 200Q - Chipped 1.8 Bar
>
> Symptoms - hissing under boost, max boost about 1.3 bar definitely
> leaking
> boost SOMEWHERE. Car cuts off power if boost demands get higher
> than moderate (not gentle) acceleration. RPM not dependent. Didn't
> have time
> to recheck using the dipstick test, but it did fail prior to my
> temporary
> patch.
>
> Probable cause - leak. In the time availible, I've checked all of
> the vacuum
> hoses, MM hose, ISV hoses manually. Rechecked valve cover gasket.
> Did find
> one hole in the "T" breather hose on top of the valve cover, fixed
> a
> temporary patch with rubber tubing and a hose clamp. (part will be
> ordered
> today). SO, it's down to the lower IC to Turbo hose (yeeesh, $$$) or
> the IC
> itself. Or it COULD be the boot over the airflow plate, but that is
> new as
> of last year.
>
> Question 1 - how do you check the IC for leaks?
>
> Question 2 - where are good sources for lower IC hoses?
>
> Question 3 - could a torn WG diaphram cause any of these symptoms (I
> don't
> believe it could, as it's not in the intake stream, right?)
>
> Question 4 - HOW or more precisely, WHERE does one hook up a MityVac
> to
> hopefully cause enough vacuum to cause enought noise so that I can
> find this
> stinking leak?
>
> TIA!
>
> LL - NY
>
>
>
>
>