Rear engine needed maybe:

[Pete Somers]

Maybe you should have posted this on the Message Forum page.
You need to connect a gauge directly to the oil pressure line out of the engine and start it a see what pressure you get compared to the gauge in the cockpit. A compression check would also be advisable as it would let you know the state of the engine.

1 What is the oil pressure when cold.
2 Does it go down rapidly when the engine warms up.
3. How much does it vary with RPM.

Regards
Pete