[65rsr]

Check the driving shaft / driving wheel key!

I had a strange experience with a brand new defective 930 oil pump. Pump was a brand new (not rebuilt) factory original 930 oil pump that would work perfect on the engine dyno for a few quick pulls, but once it was run on a chassis dyno for a longer duration and at higher temperatures it would instantly lose oil pressure. After letting thing cool down, you could crank the engine and get pressure, again on the dyno everything would be fine and then suddenly, no oil pressure. Scavenging issue? Seals? Air? Plumbing? No. The culprit was a missing, never installed at the factory Woodruff key (is that the right term?) for the driving wheel on the driving shaft. It was never installed during assembly. There must have been enough of a compression fit for the wheel to stay on the shaft until things got hot at high rpms.