Volvo D16 - Engine oil pressure value too low

I have a Volvo 780 D16 2013 with oil pressure problems every time the l go up or down hill l being dealing with this night mare for over a year and spending money like crazy looks like the l work for truck repair last time in Volvo dealer in Kansas City MO l wast told that the wiring engine harnesses was the problem after spending over 5000 Dollars and going up hill again found out they was wrong please can any one up there can help me thank you in advance

 

Did you install another gauge on the engine to see if it really is low, or are you going off the gauge in the dash?

I had this same issue many years ago, only to find out the culprit was a loose wire in the dash circuit board where the oil pressure gauge was located.

 

I have 2009 Volvo D16 every 4000 miles my oil pressure light in the dash will come on and the truck will derate. According to the gauge the oil pressure will slide to about 40 psi. If I just change the filters, and not the oil, I will gain up to 15 psi on the oil pressure gauge for another 4000 miles. We've had wiring harnesses changed and the sensors that go with it. Could it all be in the dash? Or am I missing something else? Any thoughts on this?

 

Sounds like fuel dilution. Sample it next time.