"Following the sudden oil pres
"Following the sudden oil pressure drop at high rpms, I decided that it was possible that the pressure release valve on the oil pump could be faulty. My theory was that the pressure release valve spring was weak and that the pressure release was getting stuck.
So I swapped the oil pump by dropping the oil pan, etc. What a pain in the A$$!! The total job took about 8 hours in cramped quarters.
I tested by letting the engine idle for 5 minutes. Then I ran the engine to 2200 rpms for 10 minutes. Oil pressure looked fine at first staying steady between 40 and 60 psi. Then, it dropped and would not come back until I stopped the engine, let it sit and then fire it up again.
Suspecting a faulty sensor, I replaced it only to get the same reading. Already troubleshot the gauge by swapping it as well.
At this point, all I can think is that my oil has been pushed up into the engine, but is not coming back down to the oil pan quickly enough. This allows the oil pump to pump air, killing the pressure.
Are there any other thoughts out there. I've gotten surprisingly few responses from this thread. I can only guess it's because the problem is so difficult to diagnose and has so many variables.
To sum up, what else causes low oil pressure at moderate rpms besides a faulty oil pump?
FYI, for those of you following the thread, oil pressure has always been the issue. The alarm was never related to engine overhead, but rather low oil pressure."