Could be the actual oil pressure gauge it self, try replacing that.

 

If the dash light is coming on it's not the gauge. And when the sending unit fails it makes the gauge max out, not go low. Maybe an oil pump failure waiting to happen?

 

I have been reading around and am pretty sure it is the oil gallery gasket in the rear timing belt cover! The gasket is made out of a paper like material and it basically tears and leaks oil into your rear timing belt (internal leak). I have a 35DE engine and the gasket is not sold separately. I am thinking I need to create my own gasket for it (after taking a few days to remove the timing belt and everything...)

 

Gallery lol.

From what I read that issue only applies to rev-ups. The gasket is available at Nissan and was revised to not blow out. But you have a DE.

 

http://www.courtesyparts.com/13533m-gasket-oil-gallery-350z-z33-2003-2008-p-17118.html

That's the part! I have found a few forums saying that it also is a problem in the DE engine. I have replaced the pressure switch which wasn't the issue. What do you think the issue is? No external leaks, no compression lost, no temp fluctuations, no timing faults.... Just at idle I get low pressure.