I just got my ls1 into my 94 and after about 300 miles I am not having problems with oil pressure. On the way home form vacation my gauge started flipping out. It was bouncing erratically between 20 and 40 psi when just crusing at 1500. Almost so much that I would have ruled it out as an electrical problem with the sensor. Before dropping the motor in, i put on GMPP ported ls6 oil pump. Also did a new cam, rockers, springs, lifters. Got it back to the shop, hooked up a mechanical gauge to it and it read the same rapidly changing oil pressure. Pulled it apart, put another new ported ls6 pump on it as well as a brand new pickup tube. Put it back together and it wasn't changing as rapidly but it wasn't really going past up too or past 40 at any rmp. Even before i took it apart and afterwards as well, on the way home as RPM increased, oil presser would decrease down to about 20 psi. Last night pulled the intake which had oil around gaskets at the intake ports (heavier on ports 1,3,6,8) and some oil colored walls in the intake ports. Also looked to be oil residue on the pistons and on the back of the throttle blade. So it seems as the oil is originating at the intake and flowing down. Only thing is the PCV system just has filters on the valve covers and its not hooked up to the intake manifold. So I have no clue where this oil is coming from. I also tried to clear out the tunnel from the output of the oil pump through the oil filter with some brake clean. That only resulted in some oil coming out, but no blockages. Also must say that I found some of the oil filter media on the screen of the pickup tube. Not much but some. Also saw some scaring on some of the cam lobes and on some vertical scaring marks on the bottom of the lifters near the roller.

At this point I have done everything but take the cam and rotating assemble apart because I didn't have my pulley puller with me last night. I would write it off possibly as a spun bearing, but after checking two oil filters that came off the car, there was not a trace of copper to be found. Also no knock that sometimes accompany that problem.

I really need some help on figuring this one out if you guys have some input.

 

I haven't seen good results from people playing with/disabling their PCV system. It would be a good idea to hook it back up and convert to the LS6 PCV system including the LS6 lifter tray.

 

Thicker Oil Pump Pick up O ring.. There actually is a TSB for it.

Seeing as you installed the new ported oil pump, the smaller O ring is causing Oil system aeration. That's what's happening. Or the O ring was pinched upon install. I know that pump can be a MPITA to deal with, but you should replace that O ring.

It happened on my buddy's car after a H/C, oil pump install. It was also causing a bad valvetrain ticking. After the new O ring, the oil pressure sits FIRM at 60psi now.

I'm 100% sure that's your problem.. Thicker oil pump o-ring GM# 12557752, That's the P/N we used.
vid... I was waiting for it to drop down to 25psi, like it had before..
http://www.youtube.com/watch?v=gJxTVOYiwOI

TSB INfo thread w/ links.
http://web.camaross.com/forums/showt...ump+pickup+TSB

Especially addressed in this thread.
http://www.ls2.com/forums/showthread...hreadid=510675

MS4 Cam swap valvetrain ticking info that we were notified about the O ring.
http://www.ls1tech.com/forums/showth...0&page=1&pp=20
http://www.ls1tech.com/forums/showth...0&page=6&pp=20
http://www.ls1tech.com/forums/showpo...&postcount=109
http://www.ls1tech.com/forums/showpo...8&postcount=59

Thicker oil pump o-ring GM# 12557752

 

I used one of the new larger o rings from the get go. It had no problems make 60 - 80 psi for 4 days and then just let go all the sudden. If it was a problem with the O ring, it would have shown from the start. Also after removing the ring, it showed that it was not pinched.

 

^ huh.. Maybe just a bad pump?... .. Stupid question, but was the pick up tube flush with the pump when installed?

Well I'm tapped out..