Z06_N_SD

Hey guys...yes I know, it's not a vette but my other vehicle has had low oil pressure at idle since I bought it. Long story short...it idles around 600 with under 5psi. It has roughly 80k miles on it. When I put my foot on the gas and bring it up to 800-1000 the warning/ding sound stops. I have always used mobil1 5w-30 and now I'm realizing I should probably kick it up to 15w-50 or just go with petroleum(no more synthetic). I put half a quart of that thick Lucas oil additive in it with no luck. Otherwise, it runs fine and no engine noise. Can I even adjust the idle screw? I didn't see one, or is it computer controlled only.
Do you think thicker oil will raise the psi enough to get rid of the annoying beep?
Any input would be appreciated. Thanks guys!

C5Natie

Thicker oil will just mask the issue and that Lucas stuff is crap. Do a search on low oil pressure in the forum and just diagnose the truck the same way. Use a mechanical gauge to confirm the dash reading. Is the valvetrain making a lot of noise? I would assume it would at just 5psi. At that pressure im not sure if its enough to float the crank. You may be looking at a serious bearing or oil pump issues so I would try not to drive it until I did a full diagnostic check.

SteveDoten

never seen an LS that low, I've replaced dozens of bad OPS's though.

Pull the motor, put LS3 heads on it and a nice cam, then swap it into the C5

Z06_N_SD

Thanks guys. Well what I've been doing is unplugging the sensor so I don't get the beep. Engine noise-nope, none. My wife drove it cross country From CA to VA. I've never had a problem with it. I also did do the manual reading and it is in fact low. Once it's given gas, it is fine. Not as high as the Z06, but it'll get up to about 30psi WOT.
Oil pump? Oil pressure bypass valve? Use thicker oil? I really don't think there is any internal engine problem. Although, you could say, with pressure that low-there must be a problem. I'm going to be selling it soon and I'd like to
Square away the issue before I pass it to someone else.

Z06_N_SD

Haha....nice

C5Natie

Maybe youre not too sure what noise to listen for because if it is indeed at 5psi then the lifters aint pumping up. These valvetrains are already noisy enough so most unexperienced owners might miss it. Imo, it sounds like a bearing issue. Usually when the pump bypase is stuck open you get 0 pressure unless maaaybe it gets stuck on n off but I doubt that. Most pump o ring issues ive seen are after install and the o ring is pinched. Rarely, in fact never, have i personally seen them fail on a seasoned motor. Looks like youll have to tear into it for sure. Just do the corvette community a favor and dont just put 20w50 in it and sell it without disclosure of the issue. Not saying you'd do that but it definitely happens.