Re: The damage so far...

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <000101be966b$78003860$5b02883e@default> "Jim Haseltine" writes:

> Firstly - one wrecked turbocharger - worn bearings, blown seals - it could
> be reworked but "Quite honestly, some of the parts are one step away from
> scrap...". So its being rebuilt, only the air impeller and the front and
> rear housings can be reused. Cost? - I'll find out later in the week.

Check with Roger Galvin when you hear.  He just got an exchange (=new)
turbo from Reg Vardey's in Leicester at a price that made me choke on
my beer.

(Well, almost.  It was a pint of Judge's, a local Rugby beer that is
 _stupendous_.  I realised I was choking, and then on what, and
 successfully suppressed the reflex.)

> Curious thing though is that although the bearings have suffered from oil
> starvation, enough has been getting though to burn off in the exhaust.

Nah.  Quite normal.

> Secondly - one seized auxiliary water pump. The whole thing is locked solid,
> the impeller won't turn at all. I know that this was working last October
> when I changed the coolant - that was probably the last time that it did
> work. The VAG price is enough to make a lottery winner worried so I'm
> heading for the Bosch agent tomorrow.

I'm sure this is fresh in your mind, from my stripping of MB001293:

   I think I've found the problem.

   The engine is fine (all within tolerance) and can be rebuilt using
   only new gaskets, seals and studs.  Perhaps lifters.  The turbo
   oil seals are shot on the inlet side - no physical damage, but it
   needs rebuilding for new seals.

   The culprit?  The after-run cooling pump is seized - the motor
   runs but the impellor doesn't turn.  I suspect that the owner has
   not been observing the 40-second idle down recommendation, and
   this - combined with the absence of a cooling water flow - has
   cooked the seals.

   It adds perspective to the old argument about whether it's
   necessary to idle down a water-cooled turbo.  In theory, it
   probably isn't - but you can never tell from the outside whether
   the damn pump is working or not.

   I know others have commented on this feature of the pump - this
   incident is (IMO) proof positive that idling down is a Good Idea,
   no matter on what engine.

   Also IMO - it's worth adding a take-off-and-test check on the
   after-run pump to the cam belt procedure - the coolant has to be
   dropped to change the water pump, so why not pull the turbo
   cooling pump at the same time and see if the impellor turns when
   volts are applied?


--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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