Re: Blown turbo? - not a pun...

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

In message <000901be95a5$ff0961e0$a54f883e@default> "Jim Haseltine" writes:

> Pulled the turbo today, the impellor isn't touching the housing but isn't
> far off it - the axle has play in all dimensions and rattles when I shake
> the unit. There was something like 2-3 tablespoons of oil pooled in the
> intercooler inlet hose but none at all in the turbo - by this I actually
> mean in the oilways, I removed the oil feed and return lines and didn't get
> a single drop of the stuff out of the turbo - its now been sitting on my
> bench for 6 hours and theres still no sign of any.

Apart from the axle play (which sounds nasty) that's all normal.  The
turbo doesn't retain oil internally and rarely drips from the proper
channels when removed.

Take care with the word 'axle' - play is described as 'axial', or along
the axis of rotation, and 'radial' - at 90 degrees to it.  It sounds
like you have severe radial play.  Would you like me to dig out the
specifications?  It's a clamped dial gauge job.

It's normal to find frighteningly large amounts of oil in the inlet
system - some of the gas volume comes in via the breathers containing
vapourised oil, and suddenly hits a subsystem designed specifically
to _cool_ the airstream.  So the oil vapour condenses out.  A
tablespoon is about the minimum you ever find.  Everyone who takes the
post-turbo inlet system apart is shocked by the amount of oil in there.

Just as long as there's nothing gritty.

> One of the intercooler mountings was split in two and the other was within a
> gnat's of the same thing. The block breather hose is in pretty good
> condition, I'm starting to think that the breather hose that fixes to the
> air dome may not be as air-tight as it should be, it has two or three places
> that are rather worn. Tried fiddling around with my long 3mm allen key in
> the mixture ajustment hole again - still no luck, so tried another 3mm,
> didn't work so tried a 2.5mm key - fits fine and turns the mixture screw.

The L-shaped hose that goes around from the cam cover to the air mass
sensor plenum has a nasty habit of fraying through on a tie-wrap
behind the head.  Feel the underside of the hose as it passes underneath
the idle stabiliser valve.  Also - the multi-way breather junction on
top of the cam cover spilts underneath at the rear.

Someone's been turning your mixture screw with a long flat-blade
screwdriver.  This is a characteristic habit of John Coughtrie's - has
he ever been near your car?

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