If it just happened recently, the sending unit on the engine may have gone out. Check that out first. It's really just an idiot-type sender, not a true gauge. On high-mileage motors, the main bearings will get worn enough to cause low pressure, too. If it was the oil pump, you wouldn't go very far before hearing some serious knockin'! This is what happened to my Bronco before I bought it, as well as another Ford I used to own. At 170-180K miles, the oil pump just quit, and then there was zero oil pressure. Installing a new one doesn't help much, since the metal filings from the bearings will **** a new pump just a fast. At that point, it's time for an overhaul. Just keep a close watch on the oil level and keep listening for any knocking sounds coming from the motor.
