At idle its like 12-13psi, when I drive like in 4th 1500 rpm its like 30-35, but some times its like 20-25 at a same gear and rpm I am using 5w30 mobil one and the needle fluctuates a lot too. I was going to change to oil sending unit to see if would help but I am affraid the its time for a rebuilt the car has 70k on it. What do you guys think?

 

That sounds ok. I have about 15psi at idle, about 30 psi at least with anything over 1300rpm. It comes up with revs nicely, usually gets to around 45 psi, and usually at redline mine just touches the 60 psi mark. I also get some jumpy readings at low oil pressure. 131k miles here.

John

 

What oil filter are you using alex-z28? I have seen in my car if I use a "high capcity" oil filter it drops my oil presure dam low. The purelator filters seem to hold my oil presure good. Those fram filters suck for our cars from what i have seen. Then agian, i have 104k on the clock.

 

Yeah as long as you dont have blue smoke out the exhaust, and its above say 10psi you are fine. 5w30 is pretty thin oil, put 10 in it and youll jump up like 10psi possibly. you might want to run 10w anywah, doesnt hurt anything, only cold starts.

 

I am using ac delco oil filter, also I have blue some coming out on start up, I heard its because of worn out valve seals. Next oil change I will switch to the 10w30.

 

Could be that you have a bad pressure sensor. If you can get to it unplug the sensor and turn the ignition to on not the start position

Check to see if the oil pressure guage goes all he way up. if it does replace it it is bad. this happened to mine. you would be surprised how much pressure these motors really put out with a new sensor.

good luck