RustyGunz

So you changed the oil pump and the pressure never went above 78psi? I’d say mine hit 80psi once out of the last 5 times over 3500rpm. Usually stops at work the second last increment I. The gauge. Going to take it to the dealership to get a second opinion on this oil pressure

Thanks for the reply, so now your oil doesn’t go right off the gauge? I’m having mental trouble pushing it to that level lol I’m pretty sure my failure was from the cylinder 7 going into 4 cyl mode under load. Starting to think the best solution is a for sale sign

Ok thanks for the help, I think I’ve done all I can to avoid another lifter failure. I believe my mechanic has checked all the screens.

Ahhhhh, Ok so there is no PRV to release any excess pressure when in the high stage from the looks of it (maybe that's why I can't find any info on it haha). I'll have to get my old VLOM back and check to see what's wrong with the solenoid for that cylinder. maybe the solenoid is flakey or leaks. Would sure be nice to have some confidence that it was just the VLOM that ****ed up. There is a GM bulletin somewhere that says change the VLOM with the lifters. Since you seem knowledgeable on the subject, is it common that the oil pressure sensor is flakey? everyone I know with this truck the oil gauge (which doesn't seem very accurate or fast acting) doesn't go full scale when in high rev's. Is it common for the VLOM to be the issue?

If oil pressure was too high is it possible that it caused the solenoid in the VLOM to leak or pass oil pressure to the lifter when it wasn't supposed to which in turn causes the pins in the lifter to collapse when under load? Is the updated VLOM supposed to be more reliable? I can't seem to find any info on the oil pump PRV so maybe I am going down a rabbit hole I don't need to? sure don't want to have to go down this road again, especially trying to find a new VLOM lol. Might try e-mailing GM themselves.

Kevin, Thanks for the feedback. By plug in AFM bypass you mean bypassing the 4cyl mode right? curious how that would affect oil pressure? I needed my truck back for work so I have been staying away from high RPM until I get this dealt with. It really seems intermittent at the higher pressure. I have added oil treatment to see if maybe the PRV is gummed up.

Oh boy, My VLOM failed recently and took out my lifters, cylinder 7. I replaced it with the latest version VLOM. I am concerned that what took it out was high oil pressure. When above 3500RPM and the high pressure oil is activated my pressure appears to climb passed 550KPA. My mechanic said he saw over 100PSI on his snap-on diagnostic tool? Is it possible that the pressure relief valve is sticking? this is only intermittent, sometimes the pressure stops at the 7/8 mark, sometimes the needle is buried. Has anyone else seen this?

Hey, Had the exact same problem. 2015 Denali 5.3L. Lifters in cylinder 7 failed, mechanic did not replace VLOM and lifters failed again very soon. Lifters and VLOM replaced and seems fine. Figured that the VLOM solenoid for cylinder 7 was leaking allowing oil pressure to the lifters. This causing the pins to be pushed in far enough to let the pushrod collapse when the camshaft is pushing on them in V8 mode. which makes sense as I noticed both times they failed was when the oil pump was on high pressure mode (+3500RPM). My mechanic is thinking the VLOM possibly failed as the pressure relief valve in the pump seems failed as my oil pressure climbs above 550KPA when under high engine RPMS. I can not seem to find any info on high oil pressure. So even with the 4 cyclinder mode deactivated there is still the possibility oil can get to the lifters causing them to fail.