My dummy gauge on my 6.7 went to zero when driving. The truck has a 6psi oil pressure switch, and doesn't show anywhere near what the actual reading is if a real mechanical gauge was used. Typically with a real gauge the pressure is 20psi hot idle and 75psi plus on a cold start. What do you guys think happened? I restarted the truck and it went back to normal and has been working for a couple weeks now. There was no oil on the ground or any weird noises, so I don't think it actually lost pressure as I wouldn't have made it home. I would have thought the check gauges light would have come on also, but it didn't.