[Vwdiesel] 01 Golf TDi TURBO issues

[James Hansen]

> but not if the turbo's not functioning, correct?

Define not functioning first. No boost, or no turning.  Take away the
backpressure of the manifold, and the turbo even in limp will move an
ENORMOUS amount of air. It's a pump, and it does so rather well.

> (for the record, though, theoretically the majority of the energy of
> the expanding combustion gasses goes into pushing the piston down,
> right?
> and the better/more efficient the engine, the more completely that
> energy is spent
> so the upstroke to exhaust, while expelling hot gasses, shouldn't be
> fighting any real pressure from sill-expanding fumes, should it?)

Less than ~20% goes to the piston, the rest is wasted to friction (small)
and waste heat (big).  The turbo catches some of that.

> 
> anyway, all that said, I am thinking the best place to start is simply
> replacing lines
> several people have said it's hard to see/find leaks, and the turbo
> simply not working since the repair seems fishy
> who's to say they only left one thing disconnected?
> 
> any advice on what tubing to buy and where?

You need to check what holds vacuum, and what doesn't.  A hand-held vac pump
is a godsend.
I had an increasingly annoying loss of warp power that was intermittent.
One day I smelled engine.  Turned out mice had chewed through the vac hose
that takes boost pressure to the ECU, causing the "manifold actual pressure
is less than specified" code.  Boost pressure was bleeding off into the area
of the cabin air intake. Nice.  Even nicer mouse nest.  Now I have cats.
I buy my black braided stuff at the stealer.  Buy enough, it gets cheaper.
:-)

Don't let go of the wheel, just in case.
-james