Dunno if this would be the same or not, but over Christmas I drove from D.C. to
Iowa City, about 1,200 miles (VIA Detroit, to drop off a friend.) While in
Iowa, I had my oil changed at the Coralville Jiffy-Lube (no time to go anywhere
was fine for the rest of the time in Iowa, and back to Detroit. When I was
almost home (about 1,300 miles later) my oil light started coming on
intermittently. I checked the oil, level was fine. Kept on doing this for
about a week around town, so I got fed up and changed the oil again myself.
Used a NAPA filter (made by WIX), and NAPA oil (Valvoline repackaged) and I
haven't seen the light since (about 5,000 miles.) All I can figure is that the
a**h***s at Jiffy Lube use sh*t filters and garbage oil, that the pressure
wasn't what the car was used to. Try changing your oil & filter with a good
filter and oil, it' probably the cheapest test you can run. Of course, YMMV.
87 5000CS TQ