The Stovebolt Site Forums The Shop Area Engine Shop Oil pump failure ? Say it isn't so.

Could be the dipstick is not the correct one for the engine.
Maybe the pickup screen inside is not adjusted correctly or has some where it is pulling air rather than oil.

I think at the next oil change I would put in the correct amount of oil and then see where the oil comes on the dipstick. If not close then mark the stick to show full.