I have a 1985 Olds Calias Supreme 3.0 V-6 ran great until it lost oil pressure I changed the oil pump and the whole front end and still no oil pressure. It starts up and runs but no oil to the valves and no pressure. anyone got any suggestions? Confused and dumbfouded

Worn internal parts?
Cam, rod, or main bearings have excessive clearance?
Breach in the oil circuit?
Oil filter adapter check valve issue?

Can any rod, or main bearing knocking be heard?

Is a mechanical pressure gauge being used for checking the oil pressure?

Oil pressure reading?

Did you check the oil bypass valve?

Pick up a mechanical oil pressure tester. Never trust the electrical ones. If you really have no oil pressure, the engine will make a lot of noise. The lifters will not fill and you should hear the valve tapping.

I replaced oil pump & check valve, re-installed and started up, It fires right up but sounds rough but no tapping oil light stays on, I turn it off and take off the filter still full to where i filled it. is there a way to prime the oil system? Its like it lost prime and won't suck oil up to pump...

No Knocking, where do I hook up an oil pressure gauge? Same port as pressure switch?

Yep, just remove the pressure switch and put the connection for the pressure tester there. A bad switch will give no pressure reading. If you had no oil pressure, you would hear valves tapping, and rods knocking.

If I had oil pressure wouldn't it go thru the filter ? Because its not getting picked up thru the pump...

You can try to pump oil back threw where the sensor is. That should prime the oil pump.

thanks i will try it.