Originally Posted by Warlock III
A.) The "oil sending unit" and the pump are the same thing.
B.) The oil pressure switch can cause the symptoms you're describing.
I would personally just go ahead and change it and call it preventative maintenance.
Sounds like something my English language expert (AKA Father-in-law) would say.
I offer the following clarification -
Oil Pump - Oil sending unit - A device that pumps or 'sends' oil to a different place.
Oil pressure switch - Oil pressure
sending unit - A device (typically electronic) that is used to send information about the amount of pressure is in the oiling system to a gauge or other indicating device.
I agree that replacing the oil pressure switch (oil pressure sending unit) is a logical starting point. They do fail and your symptoms are typical of that failure.