I've got an oil leak in my 260z (L28 engine). Not having a lift, I asked a mechanic at NTB to see if they could find the source using their lift. I suspected either a rear seal (I replaced it a few months ago) or the oil pan gasket. Instead I was told that the upper oil pan was leaking. What is an UPPER oil pan? From what little I could find on the net I know I need to remove a cross member to replace it and it uses RTV to form a gasket, but that's about it.

Spread out some newspaper where you park it at night. Drive it then park it and look the next morning for oil spots on the paper. Look straight up from there and hopefully you'll see where it's coming from. Probably leaking from the oil pump at the front of the motor???

Never heard of an upper oil pan.

I'll give that a try after I wash off the underside.  Thanks

 You might want to slip jack stands under it and check the torque on the pan bolts first. "Upper pan" was just a lame, vague description of the source of the leak. That guy missed his calling. He could have been a politician.