Just returned from my longest trip yet in my bus. Ohio to Orlando to visit Mickey, Beverly Beach Fl, Charleston S.C., Knoxville and back home. Everything went great. Added 1/2 gallon of oil in Charleston. About 150 miles from home I look down and oil pressure is reading 15 psi while cruising at 65 mph. It had been running 40 psi while cruising the whole trip. Thought that was strange and pulled off at next exit to check oil. As I was going down the hill to enter the truck stop and accelerating pulling in, the oil pressure returned to 40 psi. Shut down engine and checked the oil and it was pretty full. I was sure if I let it set for a while it would be full. Headed back to the highway and pressure read 40 psi for a few miles then returned to 15. Drove it the rest of the way home with no problems. Let it set for 2 days and oil was full. Engine carried 40 psi cold at idle. Mechanical gauge in rear seemed very close to front electrical gauge but I have no way short of mounting a camera back there to verify while going down the road. Any ideas? Does the engine have a pressure regulator or relief that could be acting up?
It's probably an electrical connection, sensor or gauge issue. The engine does have a pressure bypass but it's won't be close to operating at 40 psi, I think it's set closer to 65 psi.