Hey everyone I'm new to the site. I like it so far it's helped me alot do far. I'm needing some help tho. I have a 89 l98 and I don't have good oil pressure it will run about 9psi when warm at an idle and goes up when rpm goes up so I'm wanting to change it to rule that out and I've looked at all kinds of pumps for it and it never gives me the same part number so does anyone have a part number for me or a picture of one I could see what it looks like thanks in advance

 

Prolly not the pump. They basically don't go bad. Forget that whole line of thinking.

The most common reason for the gauge reading low, especially if the motor itself doesn't seem to be in low-oil-pressure distress, is the gauge sending unit. You have NO CLUE how many cars have been junked for that. Go buy one and see if it's better (OBTW, don't forget to install it before you make your final decision )

If the oil pressure is ACTUALLY low, the problem is bearing clearances. You can change out your oil pump every day, and twice on Sundays even, and not make the slightest bit of improvement to the pressure, if the engine is smoked. It will need a crank kit at the very least in that case. Unless the motor is known to be in otherwise pristine condition, I wouldn't crank-kit it (or change the pump); if the bearings are toastied, the rest of it isn't far behind.

 

9 PSI (assuming the gauge is even reading correctly) at 750 RPM or so idle is fine. 10 PSI per 1000 RPM is more than enough pressure.

 

My motor is carb'd and it's got a autometer gauge on it and it's the third one I've tried so I know it's right and the motor runs good and is smooth and quite and, it's been like this going on 3years but I haven't put many miles on it so I never worried about it much, but now I drive it every day and now it worries me and I know the rule of thumb is 10psi for 1000rpm and it does that fine but barley and would like if it was better so I can drive it without fear or take it to the drags if I want and do some mods to it but don't want to waste my time on this motor if it's goin to burn up on me.

 

Agreed 9 lbs reading on the guage is low. But if the motor is running quietly
with no lifter clatter or bearing knock a incorrect guage or bad sending unit
is my guess. I would drive it with no worries. Racing it?.......NO!
My 305 HO bone stock and 150k miles runs 30 lbs at idle.

How many miles on it? If high miles then high bearing tolerances are causing
it also. A new oil pump wouldn't help.
Running a straight 40 or 50 weight oil may increase the oil pressure.

 

I don't know how many miles on it I got if from a buddy when I was in need of a motor. And it wasn't supose to have alot of miles on it but you never know. When I get on it the oil pressure will go from about 10psi to 40ish and when it's cold on start up it will have 55psi to 60psi. Pretty much my oil pressure stays with my tach hahah, i just would hate to get another motor because i love How this motor runs but When I got the motor it didn't have an oil pump so I just put a 350 pump on it but I'm pretty sure it was the old style oil pump. Does the l98 need a special pump, So after hearing all that does anyone think it could be the pump.

 

That's just what it's supposed to do.

The L98 uses the same oil pump as anything else.

 

Ok I didn't know if it used different pump or not. And if the motor would idle with at least 15psi it wouldn't bother me much. I think I'm goin to just get another motor and rebuild this one

 

What oil are you using?

 

I'm using castrol. I've had 10 30 in it and Worked my way to 20 50, I know it's thick but it's been real hot here