My 92 explorer still runs great. Yesterday the oil gauge started acting up. While running it stays where it should be. When I come to a stop it drops all the way down past the red like there is zero oil pressure. Today I started it up, put it in gear, put on the emergency brake and let it idle. According to the gauge, there should have been Zero oil pressure. You would figure it would start to tick if it wasn't getting oil. It ran for 10 minutes without any noise at all. Should I be worried about the oil pump quitting??? Or is it more likely the sending unit or Gauge???