My oil pressure warning light goes off even as the engine is cranking. The oil does not drain back into the pan, the oil system has an anti-drainback check valve that prevents it from happening. The bearing journals do not go dry, oil stays in the clearance space because of surface tension (capillary effect).
I have disassembled engines that have sat for months and it is difficult to pull the rod and main bearings off the crankshaft due to the suction created by the oil in the bearing.
1 Like