toyota surf oil pressure problems

[aussie]

hi guys just thought ill throw some questions on a toyota surf 2.4l turbo diesel i bought for my son .I tryed on some toyota forums with no luck.OK the problem with it is the oil pressure is way too high at idle like 100psi.SO far i have taken out the 2 pressure relief valves from the side cover and the pressure is the same i alsor checked the oil cooler in the block and blew in it with my mouth and did seemed blocked. I will try another one on it but dout thats the problem.THe engine needs to be freshen up but i want the problem sorted out before i do a rebuild .im also goint to try fitting a hose to the oil pressure swich hole and attach a ball valve to it and return the hose it the valve cover and see if pressure drops down hoping some one out there has come across the same problem any help would be good