Ok so first off please don’t think I’m trying to argue or make excuses for GM because I’m not. I hope you don’t have an issue with your pump that’s for sure.
But I wanna bring this to light as maybe I’m not seeing what you guys are. Also I’ve been a licensed tech for about 25 years and have worked on a very large array of cars and heavy equipment and very specialized equipment so I’m confident I have some knowledge on the subject.
Anyhow, from what i read in the other post it says GM says anything below 22psi at 1000rpm is a low limit. Ok, so at idle you are at 21psi. Idle to myself would be about 650rpm roughly say give or take 50 rpm. So if you look at your oil psi at 1000rpm I bet it bumps up probably well over 22psi. You might wanna check and see. Your pump may very well be fine. And again I could be wrong and maybe it doesn’t bump up at which point I’d be definitely concerned.
Again, please don’t think I’m against you in any way. Trust me I’m on your side. Just thought I’d bring to light what has been written in the other thread and that maybe your pump is actually healthy.
