Mayday! 2011 MP7 Granite- oil pressure shut down

[RR1]

Anyone run into this? 2011 MP7 Granite dump is going into “limp mode” and shutting down only when loaded down. Oil pressure sensor sounds, let’s me limp to a stop. Oil pressure gauge reading fine. Have replaced everything related to oil and pressure. All sensors, valves, O rings, etc. Did find zip ties from under the cover had worked their way into oil pan when it was cleaned out and bolts checked/filters changed, etc. All new 15W40 and all new filters. Nothing happens if dump bed is empty, which is how the guy was able to sell it to me this way, I guess. Main mechanic has tried everything he knows. Local Mack dealer service guy has no idea. Called two other mechanics to see if they’d heard of it before, no luck. Any other ideas? Mack center is booked out three weeks. Can’t fall that far being a small business with no extra truck. 

[joes mack]

wiring harness issue or faulty sensor could also be bad cables from batt i drove a 2012 that had a bad cable on the ground side it would make the truck do all different crap.

[Mackpro]

There were lots of service bulletins on low oil pressure issues on the MP7 engine.  We sold very few MP7 trucks when I was at the dealership and the place I work for now only runs MP8 so I never got to personally dive into the issue but it was mostly in hot conditions and under a hard pull or  in hills  from what I remember 

[Mackpro]

See if you can find Mack service bulletin FSB 221-010  

[Mackpro]

Also , all MP engines starting 2010 (DEF fluid ) have two oil pressure sensors, one for the actual oil pressure and one for the piston cooling Oil pressure.  On the MP7 they are both on the oil filter stand . On the MP8 the oil pressure sensor is on the driver side of the engine block beside the engine ECM and  the piston cooling oil pressure sensor is on the oil filter stand .  This leads to lots of confusion on both engines due to the location of which is which. The same sensor part number fits both engines and either location . Plus I believe this same part numbered sensor also is used on the fuel filter stand and the AHI for fuel pressure readings. And years ago we liked to keep no less than 10-15 sensors in the parts room due to high failure rate . A updated sensor came out and has been good for the past couple years.