Originally Posted by
LS ROB
I see. The check valve thing makes total sense. I guess I have never really thought of how those things work. I change the oil every 3k. Still haven't bought into Mobil1's 10k miles guarantee. The engine has a little over 6k miles on it and i have changed the oil a handful of times thus far with new Mobil1 oil filter every time. I started out running 5w30 and experienced lower oil pressure than i thought it should have. It would get down to around 15psi at idle but always come back up with any sort of throttle. Cruise shows 28ish psi and over 3krpm shows 38ish. It tracks with what i have found online from GM Performance pdf on the ls7. So, I increased to 10w40 on the most recent change and it pulled the idle numbers up some but still under 20psi. Basically, What I have found is that I had a good bit of oil going into the catch can and through the engine (plumbed wrong as you have said) so i would be low on oil/pressure. Corrected that, and it is alot better, but I'm starting to think that my parts selection is playing into this somehow and that i need to use factory valve covers/pcv system. I did happen to come across some information that states GM now recommends 15w40 for the ls7 but i'm not sure if thats daily use or track use. **Note: I do have a pickup tube hold down to hold the tube and pump together.