Our '88 did that once too. It was a sucking noise that varied with throttle
position.  Finally discovered that it was the mounting of the throttle body
to the intake manifold.  The screws had backed off some, and the rubber
gasket had flattened.  New gasket and careful reinstallation solved it.

Gary
----- Original Message -----
From: "Scott Terry" <sgt000@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, March 10, 2001 3:52 PM
Subject: induction noise or vacuum leak?

> Hi!
>
> I'm a new owner of an '85 Westy, my first VW.
>
> Listening to the engine with the engine cover off, I think I hear a vacuum
> leak in the area of the intake manifold on top of the engine.
> However, being unfamliar with these engines, I wonder if I'm just hearing
> air induction noise.
>
> Through examination, I have ruled out vacuum leaks in all the vacuum
hoses,
> the air cleaner/AFM, and the rubber elbow between the AFM and throttle
body
> valve.
>
> I have sprayed the engine (during idle) with starter fluid, especially
> around the vacuum connections and intake manifold, and observed no surging
> in engine speed. (I wouldn't recommend anyone try this; you could cause
> dammage to the cat. converter, an engine fire, etc.)
>
> QUESTION: When listening to YOUR (hopefully leak-free) engine, do you hear
a
> noticeable amount of induction noise coming from the intake manifold at
> idle?  Or do you think I need to keep hunting for a leak?
>
> Please send an e-mail directly to my home address (sgt000@hotmail.com)
> since I am at home and unable to check the address to which the list
> messages are delivered.  I'll post a summary of responses/solution to the
> list at a later date.
>
> Thanks,
> Scott
> '85 Westy "Pearl"
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