[200q20v] Is it my turbo?

[Brett Dikeman]

The Bosch TBV was updated fairly long ago because in Saab applications,
the valve would "hoot."

To fix the problem, they added a metal piece that drastically lowers the
resonant frequency of the valve mechanism.  It's visible as a brass ring
if you look inside the valve.  

However, I'm not sure why it would happen on acceleration; unless it
failed in some new and exciting way, this fact rules out it being the
cause of the noise.

I remember reading somewhere that automotive turbos are(or were) designed
to be overhauled every 120,000 miles or so.  Some listers have strongly
recommended simply buying a reman'd unit, and returning the old one as a
core...rather than getting slammed by an unscrupulous overhaul shop...

Brett

On Fri, 17 Nov 2000 WARATAP at aol.com wrote:

> Lately (for the last month or so) under light acceleration as the car vacuum 
> boost gauge makes the transition from vacuum to boost, I can often hear a 
> sound similar to what one makes when blowing over the top of a soda or 
> (better yet) beer bottle.   I haven't checked the positive pressure hose yet, 
> but my IC does have a copious amount of oil at the bottom of the endcaps.
> 
> Anyone else experience this?  I'm still getting 20+ lbs of boost, but maybe 
> the bearing is going?
> 
> I'll be replacing the turbo afterrun pump next week (leaking).
> 
> -Ingo
> '91 200 with a few mods...130k
> http://hometown.aol.com/quattringo/index.html
>