when ever my 280zx get to its running temp. my oil pressure drop low whenever i letof of gas. engine only has 56000 miles.

 

when you push on the gas pedal your oil pressure rises because the oil pump shaft is turning faster, so than when you let off and the rpms drop off the pump slows down and pressure lowers mine does it too its normal...

 

Okay... you say low??? Low=??? So I just looked at my book... 43psi@ 2000rpm... as long as you have at least 10-20psi at 600rpm you should be good... I know my 70 Charger only needed 3-5psi @750rpm and that was stock... LOL now that's low...

 

Oil pressure sensor... common prob. Searchy.

 

Where are people's manners? Welcome to Zdriver brother. And yes search is quite useful on here. Feel free to check it out. Otherwise we are here to help.

Oh and as for your oil pressure... How low is it? And maybe it is what NismoPick said... Could be your oil pressure gauge. Also it could be your connections. Check the little things, before getting into the costly ones. Just a friendly tip for you.

 

if you have no oil pressure the engine will turn off. my oil on idle is about 10 psi,when i open the oil cap the engine turns off.

 

That has nothing to do with oil pressure.

 

First of all... how low is low? Normal operating (driving highway speed and at idle) is 45-ish (needle right in the middle).

A little on either side is fine.

 

well when the engine warms up at idle the gauge reads the last line whitch i guess is about 10 psi. but as soon as i hit the gas the pressure goes to about 80-85psi.

 

wow thats a big spread, mine shows half way at idle at temp.

is the needle twitchy at all?

 

no not really, but it does move pretty fast from low to high pressure

 

My sensor only reads (half) when i let OFF the gas pedal (under load) but when i accelerate, then my gauge hits the red light. I'm assuming it's the sensor so i'll check it during Christmas break and tell you how it goes if you desire

 

what do you mean "hits the red light" you mean it makes it come on or its over the red light?

i belive half and a little above half are pretty much where its supposed to be, nothing wrong with a decent ammount of pressure as long as its not blowing and seals or gaskets under load because of extreme oil pressure.

mine start at half at temp but it goes to about 3/4 the guage face if i am flyin....and boy do i mean flyin

 

My oil pressure gauge went funky after removing the center cluster a few times for other things. I just replaced it with an aftermarket unit from autometer. Most people will tell you that you need to re tap the pipe threads for and aftermarket sender of get an adapter. I just jammed mine in and it doesn't leak. It's only one thread per inch difference between British Pipe and American Pipe.
2 1/16" gauges fit the holes in the cluster with very little modification.