[Alpines] Oil pressure regulator valve

[JACranwell at aol.com]

Lauri,

Assuming you have the correct tolerance between the bearings, and the crank, 
then it is most probably the oil pump, unfortunately.

Personally, I always replace the oil pump, or at least check the tolerances, 
as per the manual, when I rebuild.

However the good news is at least you can get to it with the engine in place, 
sump off, which is more than you can do on most modern cars.

Other likely causes would be loose or cracked oil feeder to the rocker shaft, 
or the bypass valve, as previously noted.

It may be worth trying another gauge, but they rarely fail.

Good luck,

Julian.