if it was mine i would pull tha pan and take a look around check you pick up tube and pull a couple of bearing caps to see whats up. i have changed bearings in place before if you can't change out the engine right away you can sort of freshen up the bottom end if the crank is not grooved up and if you pull the pump youy may find it is grooved as well all this stuff will drop the pressure and is easy to replace which could keep it running for a long time yet. good luck