Hi guys i need to know who can help me.

I got a used engine with this problem. When cranking oil pressure reaches 80psi, after that it lowers to 20-25 psi. When accelerating oil pressure reaches a maximum of 35 psi. We inspected and found particles, so unhappily we decided to rebuild

New Bearings, new pistons, new rods, new oil pump, new oil cooler, etc.

Im having the same issue, no visible oil leaks, good compression, etc.

Im losing my patience with this engine

 

What year is the block from?

The 08, 09 (RA) and some 10’s had an extra oil squirter on the outside of the block in the timing chain area lubricating the timing chain.
Ive heard of people having issues like yours because the machine shop or engine builder removes this squirter and don’t plug the hole afterwards causing a massive oil leak.
Other things to check would be all the oil galley’s plugs (always should be removed and replaced for engine machining) and the few ball plugs on the head.

Another oil pressure issue I’ve seen is people delete the oil cooler by just plugging the oil ports on top of the oil filter housing and either use the wrong (too long) plugs or don’t delete the thermostat.

Are you 100% that your oil pressure sensor is good? Have you checked with an alternate sensor or whole different setup?
Where are you measuring the oil pressure?