bear with me, I'm new to hondas. I just got this 93 civic, 1.6 engine, auto. drove it for 250 miles and now I have no oil pressure. goes to 60 when first started, then drops to 0 when it reaches operating temp. it has 121000 miles and has been well maintained, the records came with it. my ? is where should I look for the problem? and yes, I'm a mechanic, just new to honda engines, thanks

oil pump, sending unit, lines

replaced the sending unit, no change. put a pressure gauge on it, 60psi cold. when it hits operating temp, I hear a sound like the pump is cavitating, and the pressure drops within 20 seconds, leaning towards a bad pump, maybe a plugged pickup?

replaced the sending unit, no change. put a pressure gauge on it, 60psi cold. when it hits operating temp, I hear a sound like the pump is cavitating, and the pressure drops within 20 seconds, leaning towards a bad pump, maybe a plugged pickup?

sounds related to clogged pickup. drop the pan and have a look.