maddss99

Did you ever figure out what the cause of the low oil pressure? Pump, O-Ring or Relief valve ?

07 Suburban, 215k, AFM delete kit installed with new Oil Pump (Mellon M365), new Oil Pressure Switch, oil screen removed, new O-ring and a L92 Valley Cover. So when the truck is cold the oil pressure is about 55psi, once the truck reached normal operating temp, the oil pressure drops to just below 20psi. It stays about 20psi when the truck it at idle or just above when at 2000 RPM. I do not hear any ticking sound when the truck is cold. It throws a code of P0251. Possible problems 1. O-ring may have been installed incorrectly, 2. Oil sending unit might be bad 3. Oil relief valve in the pan might be stuck. Any help would be great.