Low oil psi at idle after warm up

[UrN2nd]

I got a 96 gst auto. After a long wait I finally got the junkyard gst on the road. I rebuilt the engine and when I did I opened up the oil pump and inspected everything and it looked good. I just did another oil change, I think 10w-40 bc when this started I figured I had thin oil from the break in. When I start it up I don't really have oil pressure but it slowly rises. When I drive it's at the middle line. But after I idle for a few secs it drops to the lowest line. The wire from the sender looks good, the sender I guess could be questionable, yes I know the stock gauge sucks. I need a good oil psi gauge. But just wanna make sure other people have had this problem. I don't wanna mess up my motor.

 

[2gjlc]

You can't use the stock gauge. Get an aftermarket oil psi gauge so you have real oil pressure numbers to go off of.

 

[dugan33]

The stock gauge will read below the lower middle notch at warm idle that's normal for both 1g and 2gs. The stock gauge notches are for only good for reference during highway operation I've been told. Since it's a new motor try doing a mechanical pressure test at warm idle. And yes it's a good idea to get an aftermarket oil pressure gauge

 

[UrN2nd]

How do I do a mechanical pressure test?

 

[Kapok6]

Get aftermarket gauge.