Generation IV Internal Engine - LS2 Starving Oil Pressure Thread
12-27-2007, 06:49 AM
Hey guys, I'd like to have you take a look at my thread on LS1GTO. I didn't see the need to repost everything. It's a short thread with photos at the end, hoping I get some of your opinions.
Basically the oil pressure started to slowly diminish over a long period of time, a few PSI a week but would fluctuate back up--so it seemed like things were working. Until one day it began dropping very fast and never came back up, which is when I parked it and tore it apart.
Here's the thread:
12-27-2007, 08:47 AM
I looked at all the pictures of your engine. Did the cam bearings have the knotch ground into them from the factory, or is that something someone else did? To me, it looks like the bearings weren't installed correctly. It looks to me like they were driven in too far, or not far enough. In one picture, you can see where the bearing is sticking out of the block journal about 1/8". I have never seen that on a SBC or BBC, but I haven't installed any LS cam bearings. If the bearings aren't installed right, the oil pressure will never be what it should and engine damage is always the result. Your main bearings have way too much wear for a low mileage motor. Maybe someone will post pictures of a block with the factory cam bearings in it, so we can see what they should look like.
12-27-2007, 09:37 AM
Well, the oil pressure was fine (45-50 @ hot idle, 60 wot) for the longest time, then it just began dropping gradually until one day it went from like 30-4psi. When I got the block back from the machine shop, the cam bearings were installed 'proper'. They walked is all I can figure, but I'm like, why on earth would they walk?
So I'm still wondering if it was the cause or the effect. Everything else seems ok. I've got a new Melling HV pump on order to replace the stocker with.
12-28-2007, 11:22 AM
We have seen this happen with the cam bearings before. We have actually started using green locktite sleeve sealer on them to make sure they do not come out. It seems to be an isolated problem with the LS2 blocks only but we glue them all now.
That is the reason for the oil pressure drop. Have someone check the cam tunnel bore with a dial bore indicator to make sure it is still with-in spec and if it is, clean the block, lock in some new cam bearings and put it back together.
Best of luck,
01-11-2008, 02:11 AM
Yes, unfortunately we have seen those problems before.
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