It's a 1995 not 96.

Okay, so about a year ago I was running 0W20 full synthetic and on hot days the oil pressure light would flicker a bit at idle. I changed the oil a bit early (2,000 miles left in the 7,500 mile interval) and started using 5W30 (or whatever the oil cap says) and the problem went away...until now. Yesterday I added about 3/4 of a quart (261,000 miles on the engine) but all I had was some more of the 0W20 synthetic. Now after about an hours of driving, my light is flickering at idle and comes on solid if if I apply the brakes while while coasting in neutral (manual trans).

I assume that low pressure does not necessarily mean low flow. I'm sure all of the tolerances are way off for an engine with this many miles and I could just have low pressure because there is less restriction to the flow of oil. Or my oil pump could be failing, pressure sensor could be going bad.

Idle is steady just a hair above 750 Rpms. I bumped it up a touch last year to keep the pressure up at idle.

Should I be concerned here or just switch to 10W40 in the summer?