2003 Nissan 350Z Oil Pressure Question.

[xCOMBATx]

Well. I contacted Nissan dealership concerning this question but I've been told that my car is out of warranty. For some reason, my oil pressure gauge is pegged at over 120psi everytime the engine is running. When the engine is off but the key in the ON position my oil pressure is at 0 psi. I've rode my car for a bit (couple of days) but I haven't had any problem. I'm thinking that my oil pressure sending unit went bad(which is under my oil filter) went bad. I'm thinking it shorted out or the sensor membrane is stuck. Anyone had this similar or heard this problem before, on any VQ35 engine series? Thanks.

[Darius]

Your oil pump is a mechanical pump running off of your crank, therefore, pressure will be zero when the engine is not turning. According to the FSM, the oil pressure should be 14 psi at idle, 43 psi at 2000 rpm, and 57 psi at 6000 rpm. Sounds like your sending unit is toast or that you have a blockage downstream of your sending unit. I'd put a mechanical gauge on there to see if your sending unit is bad. If the result is the same, then I'd start to worry about big issues.

[xCOMBATx]

Well, I went ahead an placed an order on a new sending unit. I also have an OBD2 scanner. Do you think it will discharge a code even if the CHECK ENGINE LIGHT is off? Since it seems that you have a lot of tech data, does it mention anywhere where I can check for resistance on a multimeter and their nominal range? Thanks.

[xCOMBATx]

I changed the oil sending unit and it fixed the problem. My oil pressure gauge started to read normal again. It was a $60 fixed with $10 for delivery.

[xCOMBATx]

I read my original post and I made a mistake. The line where its says "When the engine is off but the key in the ON position my oil pressure is at 0 psi." I meant to say 120 PSI, not 0 PSI. The only time it went to 0 PSI was when the ignition was in OFF.