01 XJ oil pressure

Can anyone tell me the proper oil Pressure when it warms up at idle mine use to be between 15-20 psi and now I've noticed it around 10 or a hair above is that too low? When its cold and just started its up around 40 and use to drop 15-20 when up to temp and driving at idle and then goes back up around 40 on acceleration and now Like i said I've noticed it a hair over 10psi at idle anyone know whats the normal range? Thanks.

Mine's a taste over 40 when it's cold or at speed and a hair over 20 when it's warm and/or ideling. But I'm not sure if that's accurate or not. I don't put too much stock in factory gauges

The minimum oil pressure should be not lower than 13psi at hot idle. Sounds like the bearing clearances of your engine have become excessive. You could try a thicker grade of oil as a bandaid.