[s-cars] stuck in neverboost - help!

[Igor Kessel]

steve powers wrote:
> We were going down the freeway tonight when <bang>, followed by a large
> falump! vibration due to sudden deceleration. We had been doing about 75
> or so passing another car. Our car is still running okay from idle,
> though there's a large hisssss when the boost tries to come on followed
> by immediate loss of power.
>
> This tells me that it probably isn't the turbo. The hiss though is
> deceptive. You can hear it in the car at any speed which makes me think
> it may be as simple as the line to the computer. Another likely culprit
> may be the recent reassembly after the new head install - perhaps the
> dealer didn't tighten one of the boost hoses properly. Final possibility
> would be a burst hose.

Steve, in the descending probability order, you most likely have:
1. the little vacuum hose under the black plastic cover int he centre of
the firewall blown off the connector
2. a burst turbo hose (crossover pipe to intercooler), a.k.a The
Michelin Man Hose.
3. a blown diafragme in the turbo bypass valve

> I looked under the hood, but nothing was obvious. I'll tackle it
> tomorrow. I've got a compressor and probably will just seal the main
> hose at the air filter and throttle body. Put about 20 psi in it and
> listen for the big hiss.

make sure you disconnect and plug the crankcase ventilation hose
beforehand. You don't want to pressurise the oil seals from the inside
outwards :)

--
Igor Kessel
two turbo quattros