High temp low oil pressure light comes on after driving for a few minutes, then off when engine at driving rpm. At stop light (idle or low rpm) light comes back on. Normal driving it goes out.

If engine is getting hot at a red light and returns to normal while driving replace the fan clutch. you cannot tell by just hand turning the fan.

You need to find out why you have low oil pressure. It is normal that as engine rpm's increase, the oil pressure will rise- the oil pump is moving oil faster. Even though your light goes out, you could still have critically low oil pressure. There should be sufficient pressure at idle to keep the light off. The light will come on when your oil pressure is almost nil- I believe for some it's as low as 8 psi. Normally, oil pressure at idle is specified anywhere from 15 to 40 psi. You would have to check specifications for your Expedition. To verify oil pressure, hook up a mechanical gauge at the oil pressure sending unit on the engine block. Check with a local shop.

The causes run from easy, simple to budget busting ruin. Low oil level, wrong grade oil, real old oil, oil leaks, internal oil leaks, worn oil pump, worn crankshaft bearings. It was pretty common on older very high mileage cars to have a fluttering oil light at stops and idle. It was time for a rebuild, or time to look for another car.