LS2 with intermittently low oil pressure
It won't do it all the time, but I found that when getting off the freeway and stopping on the off ramp it was likely to happen. Every time it shows 19 psi oil pressure I can turn off, restart and it is back at 30 psi at the same rpm. I then might have to drive 5-10 miles before it would do it again.
I did verify the problem with a mechanical pressure gauge. The car has had a new oil pump, pickup tube, and o-ring within the last 7,000 miles or so. Mobil 1 oil and filter. After having my oil pump fail once and then later my pickup tube break, I probably watch the oil pressure gauge as much as the road. I am 10000% sure it has the right o-ring installed and it is in correctly.
This is in a 2006 CTS-V with 150k miles or so. Original LS2 with cam and springs. Has anyone experienced a similar issue? It's been such a headache to keep good oil pressure in this motor!
Knowing what I know now with thousands of LS builds completed I would recommend 2 things.
First of all get rid of the thin mobile 1. I understand that it is what GM recommends but in years of testing oils we have found that conventional motor oil that is a little heavier works MUCH better and will greatly increase the life of the motor.
Secondly don't get too far from home. Once you start to have oil pressure issues especially in the LS2 cars you are not far from stacking the rod bearings. We have seen more LS2 motors spin rod bearings than all other LS based motors combined.
If we can help you with the problem or finding a solution feel free to call us, best of luck with the motor.
I'm debating whether I keep driving it or tear it down for inspection. I'd hate to get it apart and not find anything obvious. If it needed a rebuild I'd probably just pick up a LS3 to put in.
Knowing what I know now with thousands of LS builds completed I would recommend 2 things.
First of all get rid of the thin mobile 1. I understand that it is what GM recommends but in years of testing oils we have found that conventional motor oil that is a little heavier works MUCH better and will greatly increase the life of the motor.
Secondly don't get too far from home. Once you start to have oil pressure issues especially in the LS2 cars you are not far from stacking the rod bearings. We have seen more LS2 motors spin rod bearings than all other LS based motors combined.
If we can help you with the problem or finding a solution feel free to call us, best of luck with the motor.
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The only other thing I found was some small metal specs in the oil pressure relief valve bore. The metal particles were small enough that it was very hard to get a photo. There were also some scratches on the relief piston. If I worked the relief piston back and forth in the bore, it wanted to bind if there was any side to side pressure put on it.
Not really sure where to go from here. The only thing left to pull are the pistons. After going in to this engine for a third time in a year, it seems like any further repairs would be another band-aid, even though it looks extremely clean inside. Seems like a run of bad luck here. Maybe it would be better to start over with a LS3. I'd really hate to have to take it apart again. Any ideas from the gurus out there?
What looks like it could be lint in the photo below is actually metal specs. This oil pump has probably 7k miles.
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