Hot idle should be above 20 PSI, higher is no problem. At hot cruise RPM, 30 to 40 is normal. If it's somewhat higher at hot idle, no problem, as long as it doesn't go off-scale. Any pressure at all indicates the bearings are getting more oil than they need for lubrication, but since the pressure port isn't at the end of the circuit a few pounds extra can't hurt. The idiot light switches turn the light on below 7 PSI, so a lot of engines are out there running really low oil pressure, and nobody knows about it.
In over 40 years of auto repair, I think I've only seen two or three oil pump failures. The rest of the low-pressure situations have been caused by loose bearings- - - -a worn-out engine in other words! High oil pressure is caused by a sticky pump relief valve, a very rare occurrence!
Jerry
