200 TQ Hissssssssss....

[Ryan Gemmill]

Kurt,

I had a problem similiar to yours on my '91 200 recently. You'll want to
check the "Michelin Man" hose between the IC and the throttle body. Take it
off and examine it carefully. You are looking for a small hole or crack. If
you don't find anything check the rubber hoses between the IC and the turbo.
My car had a crack in the hose directly below the IC. That part was around
$30 from the dealer.

Good luck, HTH!

Ryan Gemmill
91 200 1.8 bar, boge, K&N, 212k miles

----- Original Message -----
From: Kurt Wesseling
To: quattro at audifans.com
Sent: Sunday, July 01, 2001 11:13 PM
Subject: 200 TQ Hissssssssss....


Guys:

Remember me?  8-]  Been lurking for the past 8 months or so.

Patient is my 89 200 TQ with 193,000 miles on the clock, 1.8 bar WG spring,
no chip.

Last week I noticed a loud hiss from under the hood at 1.0 bar and above.
The higher the boost, the louder the hissing. Thinking it was something in
the turbo circuit, I took it in to my mech for a look.  We found several
broken EM studs and that the EM was cracked.  Not really any surprises
there.  Seemed reasonable to think that would cause the hissing.  I had him
replace the studs and weld up the cracks since a new manifold is around
$900.00 USD. Picked the car up yesterday and it is still hissing.  The
$720.00 EM repair changed nothing--made the car a bit quieter, I suppose.

Symptoms are similar to those many of us have seen with a split IC
hose--except the hose is ok.  If I keep pushing beyond 1.1 bar, I get black
smoke from the exhaust and the engine begins to stumble.  Sparks plugs,
W7DTC's, show no significant oily deposits and are light gray at the
electrodes. When I let off the accelerator the hiss continues for about two
seconds and slowly dies off, leading me to believe that some component is
being pressurized and the air is escaping from a small hole somewhere.

So what do you think--small hole in the intercooler?  The ends don't appear
to be loose.  Perforated WG diaphragm? Some gasket I don't know about?

Opinions very welcome!

Thanks,

--Kurt

1989 Audio 200 TQ, 1.8 bar ...usually!