I have a 1993 240 wagon with 214k miles on it, and I?ve owned it since it had 167k miles and 6 years ago. I religiously change the oil every 3k miles and use only Volvo oil filters. Today just as I entered a grocery store parking lot the oil light illuminated. Never seen that before. Got my groceries and when I came back the light was on, but then turned off as I backed out of the parking space. About 4 miles later just as I got off the highway and was at a red light the light came back on. This is less than a mile from my house and the light flickered as I drove the rest of the way home. In my driveway I noticed if rev the motor to 2500 rpm the light goes away, and as the engine settles back into idle the oil light comes back on. In May I was planning on pulling the engine to reseal it because I have a leaky rear main, and I?m hoping I don?t have to drop the pan right now. I?m picking up an oil pressure tester right using my wife?s car to check the pressure. Any ideas of what would cause the light at hot idle only? I?m really hoping it?s the switch or the wiring to it..