Just what the title says, I lost all my oil pressure yesterday while the car was idling, I gonna upgrade the pumps to a ls6 but if thats not it someone on ls1tech said it could be a spun main bearing??? how would that cause oil pressure loss. Cars was running fine just no oil pressure,its not the sending unit, valves started chattering and all that stuff.

 

The oil pump itself does not create pressure. It produces flow and the resistance to that flow produces pressure. Resistance is created by the orifices in the engine block through which the oil flows, and the amount of clearance between the bearings and crankshaft journals. As the bearings wear, clearances increase allowing increased flow which reduces pressure.

 

that scares me! my oil pressure droped to nothing and my idle went up like 300 rpm more than normal. does that sound like a spun bearing or a bad oil pump? I know you cant really diagnose something like that over the inernet but what do you think, the higher smoother idle with the drop of all my oil pressure really freaks me out.

 

Sometimes a sudden drop in oil pressure can be due to the oil pump pick-up
falling out of the oil pump. If this happens it can starve the pump of it's oil supply and quickly cause engine damage. Incidently it takes HP to turn the oil
pump especially when pumping oil,your gain in rpm could be due to the pump
"running dry" no load = more rpm.
It is possible to add some extra oil to the system in order to raise the oil level so the pumps inlet is submerged
in oil. Be care full not to add to much.
Note: this is not a fix however it may find the problem.

 

If you weren't ragging on the car when this happened I would say your oil pump has failed. The 1998 thru mid 2000 oil pumps have issues with gradually dropping pressure until there is none. My car is a 1999 as well, and I notice as the car gets up to temperature and if I get on it pretty good, my oil pressures drops below 30 lbs at idle and stays there for a while . A friend of mine is a mechanic at the local Chevrolet dealer and he told me this is a common problem on the earlier years of the LS1 engine. I already bought a ported ls6 pump to put in when I change my cam, so for now I am taking it real easy on it. Sounds like you need to install a new oil pump and don't run your engine any more until you get this fixed or you will ruin all the bearings in the engine ! Keep us posted and good luck !

 

yea it was idling when it failed, my ported LS6 comes in this week from Texas Speed, so we will se what happens!

 

Some 98-99 LS1s had an oil pump problem that caused many engine rebuilds. The pump has a spring operated pressure relief vavle in it (like all oil pumps do) and in some the valve bore had some smoothness issues. When the oil pressure spikes as in cold starts or high rpm blasts the valve opens to bleed off the excess pressure and with the the rough bore it sticks open dumping all of the oil pressure. No oil pressure = shot bearings. Now if this happened while idling then you might have a slim chance of minimal damage.

 

Quality control is quite a b!tch.

 

That's a lot of oil. The pump pickup on the pump itself is well above windage level. THe crank will be 1/8 (or so) submerged in oil. I suppose it would be cheaper than replacing the engine.. THis is the oil pump problem I have been waiting to hear about.

Get the pick up O ring too. It solved a lot of problems on a cam swap oil pressure concerns on a buddy's car.
Thicker oil pump o-ring GM# 12557752

and yes.. 100% on the nose right there..

 

Well I must have been doing something right Cause the Big Man up-stairs answered my prayers!( hey that Rymed) Put in LS6 pump yesterday from TexasSpeed and i got my oil pressure back! idles a little bit above 40psi.
Motor seems to have been undamaged from the Failure.

Thanks for all the Help!

 

That's great news, I 'm glad everything worked out for you!

 

You're one lucky man. Most who have the oil pump fail loose the bottom end bearings. Great to hear that you didn't.

Now do not gamble in any way shape or form as all of your good luck has been used up for a while.