[urq] exhaust turbine hitting housing???

[Ingo Rautenberg]

Had similar experience a few weeks ago and thanks to list recommendations,
found that the ~1.5" hose from the rear part of valve cover was cracked.
Almost impossible to catch without knowing what one is looking for.
Replaced it with transmission hose and the sound is gone and boost is up to
normal.  Remember, anytime you have boost leak, you can potentially overspin
the turbo, as it's working harder to deliver boost pressure that is
escaping.  Now that I think about it, higher/shriller air escaping noises
would naturally come from narrower/smaller hoses, as the velocity of the
escaping gas would be higher for the smaller area and hence would make a
more high-pitched sound.  Cheapest part I've had to replace yet :-)

HTH

Ingo

----- Original Message ----- 
From: "boomer" <cbaird1358 at charter.net>
To: <urq at audifans.com>
Sent: Tuesday, December 28, 2004 8:31 PM
Subject: [urq] exhaust turbine hitting housing???


hey guys, Just got the gold goat (83 urq) out of storage since the 4
runner's slave cylinder went out and it ain't the best. The car runs and
drives fine until boost, at about 5 - 7 psi of boost I have a sound like a
heat shield on a driveshaft dragging or a samurai sword being removed from
its sheath. It really sounds like the cartridge bearings are wobbling and
the vanes are hitting the housing. Is this possible? the car ran great and
made no noise previously pulling through all the boost range strong, no oil
smoke before or now...I have not had time to inspect further. thanks boomer
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