I just replaced my injectors and while I had it torn down I replaced the oil pressure sending unit because I'd been having erratic reading since I bought the car. Since I don't have anything to compare it to, I wondering where my cars pressure readings falls in the average for 3rd gen L98's. Right now I'm running 5W30 conventional oil, 118,600 on the odometer.
Last night, I took it out for a shake down cruse after the injector install. After it warmed up to normal operating temp, it was reading around 40~45Lbs cursing 2200~2400RPM. Showing about 15Lbs idling at 600RPM. I know the in dash gauges aren't particularly accurate, but I'm wondering what readings owners with similar stock setups are seeing on average.

 

The factory gauge in mine shows (reading between the lines) ~48 @ 2000 RPM and about ~28 - 31 PSI at idle, depending if in gear or in neutral.

 

Yeah, that's about where my reading were with the original sender unit, when it was stable. Half the time it was jumping all over the place, would drop to 0 and then peg past 60Lbs. With the new sender, readings are stable but noticeably lower than with the old sender.

 

That's a little low"ish", but not by much, and not by enough to be even remtotely a concern...

"Average" is probably something around 20 @ idle and 50 @ cruise.

Just having the pointer not stuck on the moving element of the "gauge" ( I use the word loosely when I apply it to that trim package) in quite the same place as most, can create that much variation.

 

Ive been through 3 sending units on different engines... dont trust them. Just consider it an on-off oil pressure switch because they are not accurate and none agree with each other.

 

That was what I was thinking. I got the new sending unit at Autozone, the usual cheap crap, about 10~15Lbs lower that the original average readings. I wonder if a real AC Delco unit wold be any better? I'm thinking about putting a "T" in at the sender and putting a real mechanical gauge in, at least temporarily, to "calabrate" the dash gauge.

 

Mine gauge reads almost 60 psi at idle when its cold. After the engine gets to operating temp, my gauge will read 15 psi at idle and as soon as I give is some gas to take off or rev the engine, the gauge will read 30 psi and stay there until it reaches idle again. In gear at hot idle, my gauge will still show about 15 psi.