mystery whoosh noise

[Brett Dikeman]

At 4:00 PM -0400 7/31/02, Djdawson2 at aol.com wrote:


>  If you're not building much boost, and the noise only occurs during
>acceleration, I'd take a good look at the bypass valve

I disagree(well, I have the benefit of hindsight, see below.)  Failed
bypass valves exhibit themselves by causing stalling at stop signs,
traffic lights, coming off off-ramps, etc...particularly after hard
boost.


>You can also try clamping off the line to the wastegate, and then
>check your power/boost.
>  If you get normal power and boost with that line clamped, you'll
>need to check the sensors that regulate the WGFV... check the codes
>if you can.

If you want to see if the wastegate frequency valve is being
activated, hook up a test light to the WGFV and then take the car for
a test drive.  Never disable the wastegate system.

Also, none of the above would cause the noise I heard.

What -would- cause that noise is the 1/3rd inch long crack in the
hose that joins the metal pipe to the throttle body.  Even lightly
pressurized, it made a hell of a racket...must have torn in the last
two days since I did a pressure test; I'm guessing the fixed o-ring
and michellin man hose caused boost levels to climb, and the hose was
sort of on the line...one shift, and RIP!

Yes, ladies and gents, that would be vacuum leak number FOUR.

In order of discovery:

-ECU line(this one is temporarily repaired; got a vacuum line running
out the window, which is fun on rainy days.  It'll be a fun repair;
hell, it'll be fun trying to find that green hose)

-michellin man hose crack(up top, near the clamp)

-wrong o-ring

-throttle body hose

Lets see, do I replace the turbo outlet->metal crosspipe hose ahead
of schedule?  After all, its the only hose left that hasn't blown :-)

Even though Zygmunt is now on my $h!t list for shipping my IC hose to
the wrong address, the superglue repair on the old IC hose is holding
up with gusto; if I can get this hose clean enough, I'll give the
glue a shot on it too, at least until I can find a replacement.

Just for future reference if anyone has a hose whose part number is
worn off(mine's getting there)...part number for this throttle body
hose is 034 133 6 49C.

Brett
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