b.lee

iTrader: (6)

I went to look at a 98 trans am ls1 auto 96k miles today
It was warm and when idling only had 20 psi oil pressure on the gauge. (stock of course)

It got a 40 psi pretty easily.
I didnt really get on it either.
He said he was running some synthetic oil in it also.

Do those sound like decent readings?
Would thin oil cause this?

b.lee

iTrader: (6)

If you get on the throttle a little, it will go over 40 psi.
It has 40 psi normal driving.
Let off the gas completely and it drops to 20 psi.

normal? common problem? thin oil?
oil is not low, and its nice and clean.

blue02formula

iTrader: (1)

Sounds low to me. My 02 has 130,000 miles on it, I use Castrol 0w30 Syntec and I never have been below 40 psi. Most of the time when it is warm it idles at 50 psi.

b.lee

iTrader: (6)

really..... thats not good in my case.
hrmmmm

Disturbed Bird

iTrader: (9)

mine at normal temps while driving is at 40psi and idialing is at the 1st mark what ever that is i think its 20psi

Blu99T/A

iTrader: (5)

When warm mine idles at 25-30lbs of pressure, Driving it averages 45lbs or so. I run 5-30 Castrol Syntec. Doesnt sound out of line.

Dan

iTrader: (1)

My 98 idles at 42 & running on the freeway it's 58. Switched from Mobil 1 5w30 to German Castrol 0w30 & didn't make a difference in oil pressure

JR HAWK 9

iTrader: (3)

I have rather high oil pressure, just like blue02formula. I have around 50psi idling warm and 60psi and over while cruising. At WOT it goes up to around 70psi or so. I also use GC 0w30.

TNTramair

iTrader: (15)

its not severly low but it has seen better days im sure. rule of thumb on oil pressure is 10psi per 1k rpms....if your within those parameters or higher...you should be ok.

blue02formula

iTrader: (1)

I am not sure but I think at some point the later LS1's had a LS6 oil pump.

LS1 Freak

iTrader: (7)

My 01 SS idles between 30-40 when hot and 50-60 when cruising,however, if I redline it, it goes anywhere between 65-75, I run Mobil1 5W-30 since brand new, I hope this helps, your car is fine, dont worry

toplessHO

iTrader: (25)

too high is almost as bad as too low
I wiped some bearings in a 327.
7 qts of oil in the pan x7500RPM
rod bearings were thin enough to snap like a potato chip.
I would say for most apps 60psi is fine in upper RPMS.
20 isnt terrible for idle.