Ok so my oil pressure has been reading ridiculous numbers. When I turn the key to turn on the essentials it will shoot up to 70-90 psi, it's not even suppose to be reading until the engine is running, well I turn the key and start her up and it jumps to 120 psi. So I read around and figured out it was the oil pressure sending unit. I confirmed this with a mechanics diagnosis. So I switched it out today, and it's still running the exact same. So I disconnected the battery in hope to reset it, and it didn't do anything. Every now and then it acts like it's reading right, but majority of the time it still reads the 120psi. I haven't drove it today with the new switch on I figure maybe it just needs to adjust itself. I also thought maybe its a bad gauge. Any ideas on what to do? I'm running out of ideas.

Thanks guys.

It's an 03 Touring AT, with 87,100 miles.

 

I bet it's the gauge or the connection. When it's at 120, smack the gauge and it'll come down.

Mine does the same thing. Refunded the sending unit that sucker was expensive

 

Its not stuck it just stays there while the engine is on

 

Ok, the gauge reads 120 when there is no signal. So you either have a faulty gauge or the wiring is loose behind the console. Pull the shifter plastic off and remove the center console and you'll see the wire that's held down with a screw. Tighten it down.

You say it reads normal and then go to 120. That suggests bad wiring or connection. When that happens, smack the top of the gauge hard a few times and it will come down.
I have this same problem.

 

Bad Guage or too much oil

 

I would guess that you have a wiring problem somewhere and its just a case of checking all wires relevant to the pressure gauge, unless it happens to be the gauge itself. Do you have a mate close by who is a 350Z owner and would be prepared for you to try his gauge just to rule this out?

 

Very possible the gauge is bad if you changed the switch. Or the wiring going from the switch to the harness somewhere.