On my People S 250 I replaced the mechanical seal in my water pump and my oil seal just behind it. Changed the oil, gave it a test run around the block for 15 minutes which overheated it so I immediately turned it off and burped the coolant.
But now as I idle it for 10 minutes, the oil pressure light comes on, flickering. I know there's enough oil in there and I even put in a bit more, likely too much, just to test it and I get the same result the second time. I see no smoke coming from the exhaust or evidence of mixing of coolant/oil which was my first thought having just replaced the seals.
Update: 7 hours later the issue isn't repeating. I ran it for 15 minutes. It must have been caused by coolant shortening wiring during burping of the system. I don't see why that would trigger the oil pressure warning after ten minutes of idling, but the only thing different from before is the coolant should have dried up by now.