Hey everyone I have oil pressure concerns. My issues don't immediately reflect other issues I've found so that's why I'm creating a new thread. So here it goes.
I've owned this '07 Denali (6.2L Non DOD) since ~140k and the symptoms have always been the same. With that said, at 150k I did install factory style oil cooler plumbing that routes it to the cooler in the radiator because I'd planned to tow quite a bit. About 1k miles ago, oil pressure switch was changed. Along with timing cover gasket, valve cover gasket and valley cover gasket. Previous owner had the pickup o-ring replaced at about 130k. Currently have about 185k on the clock.
Symptoms:
Cold (~32F) start, oil is at 30-35psi at idle. Upon acceleration it will climb a little to 40-45.
As it warms up (~80F), pressure will surprisingly increase. It will make it to about 40psi at idle.
Hot (~200-230F oil temp) unloaded idle is at ~20psi
Hot loaded idle is around ~16psi.
Hot cruising (~1500rpm) speed it will stay at ~28psi to ~35psi.
It builds pressure rather quick to ~30psi after idle but the RATE at which it builds pressure falls off very quickly after 2k rpms. Even at redline, pressure never makes it to 55psi.
I've only recently learned there is a secondary relieve valve in the pan. Would these symptoms be indicative of a relief valve failure? Or do you think it's a pump issue? Or a combination of both?
To reiterate, I have had these symptoms from the beginning prior to oil cooler and the new pressure sending unit. I've used a variety of different oil filters as well. Mobile one Advanced Synthetic is always changed at around 50%-25% oil life on the clock. I use a filter cutter and inspect the filter element after each change. I always locate "some" glitter but never had chunks or a "huge" amount of glitter.
I've owned this '07 Denali (6.2L Non DOD) since ~140k and the symptoms have always been the same. With that said, at 150k I did install factory style oil cooler plumbing that routes it to the cooler in the radiator because I'd planned to tow quite a bit. About 1k miles ago, oil pressure switch was changed. Along with timing cover gasket, valve cover gasket and valley cover gasket. Previous owner had the pickup o-ring replaced at about 130k. Currently have about 185k on the clock.
Symptoms:
Cold (~32F) start, oil is at 30-35psi at idle. Upon acceleration it will climb a little to 40-45.
As it warms up (~80F), pressure will surprisingly increase. It will make it to about 40psi at idle.
Hot (~200-230F oil temp) unloaded idle is at ~20psi
Hot loaded idle is around ~16psi.
Hot cruising (~1500rpm) speed it will stay at ~28psi to ~35psi.
It builds pressure rather quick to ~30psi after idle but the RATE at which it builds pressure falls off very quickly after 2k rpms. Even at redline, pressure never makes it to 55psi.
I've only recently learned there is a secondary relieve valve in the pan. Would these symptoms be indicative of a relief valve failure? Or do you think it's a pump issue? Or a combination of both?
To reiterate, I have had these symptoms from the beginning prior to oil cooler and the new pressure sending unit. I've used a variety of different oil filters as well. Mobile one Advanced Synthetic is always changed at around 50%-25% oil life on the clock. I use a filter cutter and inspect the filter element after each change. I always locate "some" glitter but never had chunks or a "huge" amount of glitter.
