GM spec is 6 psi min at idle, 24 psi at 2000 rpm. While your pressure is lower than typical, it is not too low.

Oil pressure is governed primarily by the cam bearings. You can spin a bearing and have OK oil pressure. Lots of noise, but OK pressure.

leaving out the check ball in the upper oil gallery will have oil flowing everywhere...it will drip out between the head and the block.

My guess is that you do not have a problem. I know that's in conflict with what all the other guys have said.

Do a search on low oil pressure..you'll see lot's of posts on the subject.

 

If I were to have left the check ball out what would be my best way of checking it ? Where between the block and head would it most likely be leaking? Thanks

 

The ball does not come out by itself. It has to be purposely forced out of the block. If no one did that, then it is almost certain that it is still in there. It is in the vertical passage at the back of the block where the oil pressure sensor goes. If the rear main cap was off and you were looking into the sensor hole at the top, you could obviously see straight through if there were no ball present. With the rear main cap on, it would be hard to tell.

 

Why would a good running rebuild motor have the bare minimum oil pressure? From the factory these motors hae 60 at startup and 40 at warm idle, why would it be normal for his to be just above the line?

i know that's what GM says in their book, but I was running it that low and when I pulled the pan because I suspected the pickup fell out, I had a spun rod bearing.

I would be very leary as to why my pressure were that low if I were him.

 

All the posters were talking about how low that pressure was, I simply stated it was well within specification. Oil pressure wthin that specification will not have a negative impact on the life of that engine.

We don't even know if the pressure stated is correct, all we know is that's what the gauge reads.

The pickup failling out of the pump does NOT lead to low oil pressure at idle in a stationary car....unless the oil level is more than a quart low. A spun rod bearing brings a lot of noise and rough running...the OP listed neither symptom.

The cam bearing clearance is what determines the oil pressure. It doesn't take a lot of extra clearance to yield a lower pressure.

This isn't about what you or I might do, it's to provide correct information so the OP can make a decision....

 

I have read that the pickup coming loose can cause a loss in oil pressure, although I have no experience with this.

As to the bold up there, my car was not making noise and I couldn't tell the difference in how it ran. I dropped the pan to inspect the tube and #6 was spun.

 

If he's worried about that he could always drain the oil and have it analyzed for bearing & metal contamination. Better than tearing everything apart.