Chrysler Repair: jeep oil pressure issues, pressure relief valve, valve piston

Question
QUESTION: 02 jeep liberty roughly 80,000. Had a leaking sending unit, replaced that. Now light comes on above 2krmps. pulled sensor and checked pressure at idle i have nearly 100psi. I change oil to 5w30. check oil to warm idle now at 80psi. removed gauge and installed another new sensor. Light still comes on when I am driving and gets over 2krmps(but not every time). The man helping me said something about a spring/screws valve deal that is on the pump and controls pressure.... any idea on anything would be greatly appreciated. I hate knowing that something is wrong

ANSWER: Hi Matt,
I am not claiming expertise in the Jeep engine line but I believe you have a situation where the oil pressure relief valve associated with the oil pump is not releasing as it is designed to do. I haven't been aware that over-pressurization is also detected by the gauge sensor but it may very well be the case with your engine. The minimum pressures at idle are around 5, and at 3,000 rpm are supposed to be 25-70 psi in typical engines. The relief valve piston should be checked for scoring and the free length of the spring checked for length. It usually can be accessed by removing the oil pan, but again I don't have any manuals for Jeep engines.
Roland
PS:I found your question in the 'pool'. I would appreciate your consideation of giving a 'yes' where you see in rating section "nomination to be expert of the month". Thank you

---------- FOLLOW-UP ----------

QUESTION: This is exactly what the helper thought. Due to intense man hours to remove oil pan I was told that I may as well just replace the pump while I'm at it. Removal requires lifting the engine a bit in addition to removing a bunch of stuff. Would you agree?

Answer
Hi Matt,
I am not so expert as to know what the ramifications are of excess oil pressure (probably it is gasket failure). And I don't know of any specific limits that when reached suggest that it is necessary to replace the pump. I doubt that the pump itself is the problem. What about trying 5w-20 oil? Is that within the recommended 'weights'. I hate to see you spend so much to fix something which may be acceptable without having a clear basis. I assume that your oil pressure gauge is accurate, otherwise the sensor is usually focussed on too low a pressure.
Roland
Thanks for the follow-up, and thanks for any 'rating'/nomination you might offer.