My oil light on my 91 came on once last year and that was the end of that block. But my oil pump actually failed.....so they say. i have never had one fail before, but i guess that's the breaks. I have heard many differences of opinion as far as oil additives go, but most against. The only time I ever used anything like that, was about 20 years ago when I spun a main on my 81 Pontiac Grand Prix, and i had to keep it going so I used STP oil treatment until i could afford to ditch that Rag and buy something better. I don't suppose you have noticed any oil in your antifreeze or vice-versa? Outside of leaking gaskets or oil seals, the only other thing i can think of would be your oil sending unit. On my 5sfe, it is located on the upper side of the head-driver's side, with one wire leading to it. It's a long shot, but check your disty seal, also, they leak occasionally.
