ok have a few problems first got a knock cant hear it while standing in front but if you open the drivers door and stand there you can hear it and the oil pressure is acting up when starts got 60psi when warms up got 40 psi when crusing come to a stop got about 14 psi shut it off for about 2 min and restart it got 50 psi and the other day while driveing 70mph on the highway it went from 40psi to 70psi for about a mile the oil pump is only a year old and the motor was rebuilt a year ago and im useing a mecanical guage not the stock sender im at a point where im afraid this moter is going to go the last one thrue a piston so does anyone know what could be going on

 

I would check the flywheel first for loose bolt and cracks - change the oil to next heavy weight. cut open filter check for medal - I have found on my jeeps that if engine knock is #5 or 6 cyl

 

im useing 10w40 so what oil should i use then