interesting boost issue on my 200TQA

[Kurt Deschler]

First, do not continue to drive under boost as you can overspin the turbo. 
I would pull off and inspect the Michelin Man hose the goes from the 
intercooler to the throttle body and the upper part of the J-Hose the goes 
from the turbo to the intercooler. (the silencer and hump hose parts) The 
MM hose is a Worldpac item. The hump hose can be replaced with a 2.25" 
silicone hump hose. As for the coolant, start with a coolant system 
pressure test, then try pressure testing the cylinders to check for a 
blown head gasket.

 	-Kurt

> Message: 2
> Date: Tue, 15 Aug 2006 19:00:09 -0700 (PDT)
> From: tmb <the_questionist at yahoo.com>
> Subject: interesting boost issue on my 200TQA
> To: quattro at audifans.com
> Message-ID: <20060816020009.48122.qmail at web60314.mail.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> hello again, all.   before i forget, the car in
> question is my dual-knock-sensor, MC-equipped
> 1989 audi 200TQA.
>
> last week i had the spring/ECU mod done, and what
> a difference in power!  i'd been building myself
> up for it for ages, and i was not disappointed.
>
> however, i seem to have developed a boost leak
> somewhere.  what's happening is as soon as i'm
> showing 1psi of boost or greater, there's a
> non-mistakable sound of air rushing out from
> somewhere.  it's the exact same sound as when the
> intake manifold boot gives out.   the one on the
> car is a new aftermarket item that has been on
> the car for only about a month - but it's fine.
>
> i thought maybe the intercooler?  but the strap
> is holding tight, and i can see no signs of
> leakage.
>
> the other boost hoses have been inspected, but
> not off the car, as they are a bit difficult to
> get to.
>
> when the mods were first done, my boost guage
> showed a steady 16psi of boost.  the next day, it
> showed 11psi.  now it maxes out at about 9.  to
> say it's driving me nuts is an understatement.
>
> oh, and the car now consumes a whole lot of
> coolant.  keep in mind, it seems to start and
> drive just fine, and all of the plugs are what
> can only be described as a normal colour.
>
> compression test to follow, but sicnce the car
> runs so smoothly, i'm going to assume on the side
> of hope that the 4000km old head gasket is fine.
>
> anyways, if anyone has any input, i'd love to
> hear it.
>
> thanks again!
>
> jason
> tmb