GMC Repair: oil pressure, engine oil pressure, oil pressure sender

Question
i have a 97 chevy silverado extended cab with a vortec 350 and a automatic tranmission.  the oil pressure has started to bounce up and down between 45 psi and 60 psi.  the engine is full of oil.  what could cause this problem, the truck has 163000 miles on it

Answer
Hi
The gage itself MAY be the problem.
The Engine oil pressure sender MAY also be the problem.
I would first have the pressure observed with a "live" gage
attached to the system to make sure the oil pressure is not actually jumping around like that.
I hope this helps.
Good Luck
Pawl