my car was idling (warm about 15-25 psi of OP) normal a few days ago
yesterday i realized the needle (underload) around 2500rpms pegged 120 as i was cruising at that engine speed.... so i immediately stopped.. drove slow back home and did an oil change... now @ first i thought it was a stuck releif valve in the oil filter.. so i changed it and the oil as well ( i was using 5w20) before..now im using 10w30... nothing changed.. oil pressure is still too high.. what could be going on?.. its not a blown head gasket, its not the releif valve... what could it be? PLEASE HELP!

 

Maybe the gauge is bad. I would try a mechanical one in place of the sender to get an accurate reading.

 

this might be a bad question but was the engine cold when you did that? I know every morning when i head out, even after the motor is warm, it still takes a good 15-20 minutes before the PSI settles in the middle of the gauge at 2000RPM.

 

I have seen this posted from time to time and the problem seems to be a bad oil pressure sender.

 

i replaced my oil sending unit (right next to the Z's oil filter) when it was reading high not too long ago. Nissan dealer sells it for 70 bucks or something i forgot.

 

I had the exact same problem and replaced the oil pressure sending unit, it worked like a charm. A little expensive for the unit, but worth it when compared to angst associated with seeing your oil pressure maxed out.