Looks like my 4.1 is up to it's tricks again. I have an oil light at idle again. I have a spare pan gasket, so I'll have it off again to see what the hell is wrong THIS time. It sure acts like that output pipe is broke again.
My friends and my partner can't believe I'm still keeping this old Caddy, with all it's problems:cookoo:
I'll tell all when I get the pan off (again/again):)

I installed an oil-pressure gauge and a coolant temp gauge to take the ambiguity of those telltales. The maximum stress reliever.:)

Are you sure it is in fact low oil pressure? Can you check it with an oil pressure gauge before going to the trouble of pulling the pan?

I had recently replaced the pressure switch for the oil light, but as it turned out, it didn't need it.
I'll have the pan off again soon, to find out what's going on.
It's on the back burner right now. My time is used on doing the Caddy 500 (508 now) engine conversion into my '75 El Camino. It's a body-off project.

That El Camino project sounds interesting, usually they are removing the Cad eng and putting in a small block chev! What kind of trans are you putting in this car?

I'm using a TH400 trans, which I'm going to overhaul before it's in permanently.

The other day, I didn't get a red oil light on the Caddy, when hot at idle. I'm beginning to think there was some foreign stuff in the pressure valve plunger in the pump. Had that happen on a "66 with the 429 engine once. Maybe it came loose and passed through.

If you do indeed get the light again, I'd look past the oil pump into other possible causes instead of attacking the same (possibly incorrect) spot every time. If you plan to drop the pan to look at the pump, I'd suggest you plastigauge the main bearings as long as you are under there.