85 URq developing an oil addiction.

[Andrew Asher <andrew.asher@pnz.co.nz>]

I've got an 85 URq that has developed an impressive appetite for Mobil
1.

Seems it gets hungrier the warmer it gets.  It originally had a cooling
problem that a new radiator and water pump have sorted out but still
when it gets to the "N" on the temp gauge, it sees that as time to fill
the street with blue smoke - kind of nice of it to draw such definite
attention to itself like that.

The dealers are pretty keen to rebore it, figuring that this will cure
all known ailments one way or the other - but I don't share their
confidence.  I'm figuring a problem in the valve guides or in the
crankcase ventilation system, as the problem is HUGE under high vacuum.
It also has an annoying habit of occasionally declaring the brake system
as defective ( normally when a girl is in the car - is there a perfume
sensor in the passengers seat ?) when it gets to normal on the temp
gauge ( possibly unrelated but...).  The brakes have NEVER failed and it
has never used any brake fluid.

The engine checks out on all leak down tests.  The compressions are all
even and as expected.  The inlet manifold is as clean as a whistle.
Only #5 spark plug is oiling. It has as much horse power as they ever
did.  Once warm, accelerating after coasting down a hill or sitting at
the lights idling causes a smoke screen bigger than Texas. When warm it
pumps smoke out at idle as if oil was being carefully poured through the
air intake. When cold it shows almost none of the above symptoms ( only
the slightest hint of blue smoke under hard acceleration )

Does any one know of any component failure that would produce these
symptoms ?
Is their some unusual link between the brake vacuum system and the
engine crankcase system that might explain both the brake failure
warning and also a smoke screen to appear out of the car ?
Do they have a habit of cracking the cylinder head and letting in oil to
the combustion chamber ?

Any ideas greatly appreciated.

Andrew Asher
Auckland, New Zealand
Andrew.Asher@mail.com