I posted this in the repair section but I dont think the repair section is up anymore and I still need help:

https://my350z.com/forum/maintenance-and-repair/250075-damn-over-filled-oil.html

So here's an update, because I'm still experiencing the same problem:

I didnt take the car to the shop but instead, I change the oil and filter again, tried to reset the ecu by pulling the negative connection on the battery, and test drove the car. The oil pressure is a bit more consistant but at times it bumps to 90psi at cruising speed and at idle and bumps to 120psi when I accelerate.

Whats going on?? My next theory is to check the oil pressure switch and see if thats malfunctioning and giving bad readings to the gauge.

HELP! Frustration is hitting!!!

Thanks

 

I'm leaning towards it bening your oil pressure sending unit. Located above your oil filter. I don't know how much nissan wants for one, but i have replaced them on other cars before, and i don't think i have ever paid more then $30 for one from advance auto parts. I think you need a super deep well socket to get it off, not sure though on the Z though. Good luck!

 

The sending units IIRC are somewhere between $70 and $90. I had to replace the one on my '03. It wasn't reading anything at all, just pegged to the max at all times when the ignition was on.

 

IIRC? Does it look like or similar to the pix below (The guy at AutoZone showed this and it cost about $70-$90). Where is it located and is there a way to test it if it works?

 

It looks similar to the one on the lower left side. I'd just get one from your dealer.