Oil pump going bad?

[87TurboGirl]

My oil psi is at 10 when I am at a stop light and then at 45mph it is at 25. Is this about right or too low?

Concerned because the 91 z28 with a 350 has at least 30lb at idle.

If it is bad is there a certain brand to go with or rebuild kit to buy? Standard? High Volume?

For my specs please read my sig.

 

[87TurboGirl]

ttt

 

[Vendor Defendor]

eek that sounds pretty low, i dont know if its normal, because i dont even have a oil pressure gauge but as a genral rule of thumb its supossed to be 10psi per 1000 rpms.. is the oil pressure steady? or is it fluctuating? because if it is fluctuating then you have a problem...

-neil

 

[87TurboGirl]

It seems pretty steady. Of course it will go up with acceleration and vice versa.

 

[Zero Tolerance]

I've got 70 psi at cold start up, goes down to around 12-15 fully warmed up (pressures at idle). I too have heard the theory of 10 psi per 1000 rmp, so have figured that I'm ok. Pressure goes up with rpm too.

 

[JDEstill]

Is your setup all stock? The factory spec someone posted a week or two ago is only 37 psi @ 2400 rpm. Technically, if you meet that, then you are okay, although the pressures do seem low to most of us.

John

 

[87TurboGirl]

No not stock

forged TRW pistons, 210/205 Lunati cam, lunati lifters, rocker arms, double roller timing chain, o'ringed heads, balanced rotating assembly, Ported and polished iron heads, port matched intake,KB oil booster plate,42# injectors with Cotton performance matching chip, stock turbo.

 

[JDEstill]

oh yeah, sorry, I tend to ignore all the garbage people stick in their sigs. My bad.

I'd expect higher pressures with a setup like that. Plenty of reasons why it would be low, some easy to fix and some not. The idle pressure doesn't sound outragouesly low, lots of people have an idle pressure like that, but your cruising pressure does sound a bit low. What rpm is that 45 mph at? Oil pressure is a function of engine rpm, not mph. How high does the pressure get when you get on it, at say 3000+ rpm?

John

 

[87TurboGirl]

on the highway which is about 70mph the pressure is about 60psi. I am not sure what the rpm's are I will pay attention when I go out later today and will post them.

 

[Brian Mc]

I have about 22-25 at idle hot, 50 at 45 mph, and about 60 at hwy speeds. This is on a newly rebuilt engine.