I recently had my oil pressure drop to 0 the warning displayed "No Oil Pressure" and audible chime sounded . Pull over shut it off check the level all fine start it up back up to normal 40 lbs at idle . I'll make this short this problem was intermittent for the next couple weeks, there was never any valve tappet chatter or engine knock , I had replaced the oil sending unit two years prior because the gauge was pegging out at max 80+ lbs. that solved the problem then and what do you know I replaced it again and it solved the problem again. I went on the forums read everyone's do this and that's, oil pump siphon tube, cam bearings, servos, get your oil analyzed and in the end it's the simple things. The 40 dollar sending unit. My wife was freaking out thinking the motor was going to blow I told her if you really loose oil pressure your motor will let you know because it will start to chatter, then knock then it's over. I hope this helps and you don't go through hell trying to figure it out.