Loss of Oil Pressure - A4 1.8T

[Vic Norman]

Patient: 1998 A4 1.8T
Symptoms: Sudden loss of oil pressure.
Oil warning light came on, owner drove a couple of miles to local Audi
dealer who told him he needed a new engine and turbo (at some exorbitant
cost). Owner decided to cut his losses and sell the car. Which is where I
enter the story, being a sucker for a car in distress. Started the car for a
few seconds - valves certainly rattled. Changed the oil and filter - no
improvement. Hooked up a pressure guage in place of the pressure sensor next
to the filter - NO pressure registered. Dropped the oil pan. No sign of any
debris in the pan to indicate bearing or other engine damage. Removed the
oil pump, pickup filter wasn't clogged, pump looked fine - what can go wrong
with a simple pair of gears? Pressure relief valve looked fine - certainly
wasn't stuck open. The pump is driven by a splined shaft - splines look
fine. Tried blowing compressed air through the oilway - no resistance...
Took off valve cover - found some chewed up pieces of plastic in the area of
the camshaft chain. No idea where they originated.
Sooo...I obviously have some sort of break in one of the oil paths,
preventing the pump building up any pressure. Anyone on the list have any
ideas on what went wrong? I would hate to tear down the engine and find out
it was something simple...
Thanks
Vic Norman 1998 1.8T