An oil pressure of 0 at idle would be very dangerous. The manual indicates
that between 8 and 10 is normal. The oil light comes on at or around 5-8
psi ( I have tried to convert from the metric figures provided in Haynes).
A general rule of thumb is 10 psi per 1000 revs. Haynes's says that
pressure should be 40 psi at 4200 rpms and an oil temp of 80 degrees C.  -- 
Meaning that they expect oil pressure to be lower when the oil is hotter.
It would be interesting to hear what other manuals call for.

The real concern is what the oil pressure should be at high speeds when
the engine is working the hardest. There appears to be little consensus on
this judging from discussion on other newsgroups covering various engines.
My guess though is that oil pressure in VW's is generally lower than
water-cooled engines perhaps because the distance between bearing surfaces
are bigger and
drill holes are larger. 

A secondary concern is if you are getting lousy oil
pressure at startup when the engine is cold. This could signal lousy big
end bearings, or a bad oil pump. Gauges are useful to the extent that they
forewarn immanent disaster. If you note a precipitous decline in oil
pressure this could save your engine.

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David Carment
School of International Affairs
Carleton University
Ottawa, Ontario
K1S 5B6
voice - (613) 788-2600-6662
fax - (613) 788-2889
Email address: dcarment@ccs.carleton.ca
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