Stock oil pressure is definitely not 11psi. Mine sits around 2bar (30psi) when fully warm.The standard gauges are full of shit anyway mate! If you're concerned fit an aftermarket gauge and have a looksee. Stock oil pressure on the GTiR is just 11psi when warm (yeah I know, but it's true). With my Defi gauge oil pressure when warm is 1.3bar with ACL bearings (RB26).
as he said, could also be a dodgy conection to the pressure sender or a dodgy earth somewhere.Dented sump?
got tip, think i'll do the same.The OE oil pressure warning light is too low (around 5psi) and if it goes ON it would be already too late for the engine. I changed mine for a 1bar sensor.