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Went out for some freeway pulls in my ECS supercharged Grandsport M6. I missed the 2-3 shift HARD a few times and the rest of the runs were fine. I checked my gauges and saw I was only @ 15 PSI at cruising on the freeway. I'm usually 40 psi hot with this dry sumped engine. I came to a stop and watched my oil pressure drop to 10! Somthing is way wrong. I started the car up the next day. 40 psi at idle cold (usually 80). Zero weird noises, ticking, or clunking. I let it get up to temp and went for a ride. I watched the oil pressure over 15 min slowly drop rack down to 12 psi at idle. When I accelerate, jumps back up to 35 psi. Again, zero weird noises. Today, I drained the oil through a paint strainer to catch any foreign material. Nothing shows up. So I yank the oil tank and open it up. On the internal oil tank filter I find aluminum colored flakes. Not copper colored. Now I'm into something. I pull the oil filter and cut it open. Same colored chips. So here's my question for the guys who have first hand experience, what do you think it is? I doubt its bearing material. Looks like the oil pump possibly broke? Let's hear it fellas.
FWIW, the OEM bearings don’t have copper in them. They're an aluminum silicon alloy. If that’s not bearing material in the filer, some of the smaller bits could have gotten through and hurt the bearings anyways.
I got a grand sport ls3 vette at the shop tht dropped a valve and damaged a piston. Its a manual dry sump setup. Finding a good used replacement engine has been a big pain. Cant find one anywhere. If u do find one they are extremely over priced like 10k range. Hopefully yours is something simple or easy to fix. Good luck!
I'd say it's bearing material. If an oil pump broke, you have bigger issues and noises. Not many sources of moving/rotating/loaded aluminum parts in your engine.
Does the material stick to a magnet?
Do you have a tuning/logging software that you use?
Is there any knock retard?
Detonation knocking the bearings out of it?
What's the rev limiter set to?
Over-rev causing crank flex and taking the bearings with it?
Factory LS cam bearings are kind of poo-poo also.
I have a wet sump ls3 currently at the shop tht was supposed to go in a customers grand sport. Will tht wet sump ls3 drop right in place? I understand i would need to remove all the dry sump stuff. But im more worried about oil pan clearance and belt alignment.
Last edited by brandon6.0; 06-05-2018 at 08:35 PM.
I have a wet sump ls3 currently at the shop tht was supposed to go in a customers grand sport. Will tht wet sump ls3 drop right in place? I understand i would need to remove all the dry sump stuff. But im more worried about oil pan clearance and belt alignment.
I was told that the engine sits lower in the stick GS because of the dry sump. Lowers the center of gravity to promote high speed cornering
I was told that the engine sits lower in the stick GS because of the dry sump. Lowers the center of gravity to promote high speed cornering
I doubt that to be true. It would alter the "trans tube" and rear diff angle if the engine were lowered. Besides, the "dry sump" pan isn't that much lower than a standard pan anyhow.
Aren't factory bearings bi-metal (aluminum alloy & Steel backing)? You won't see copper. How soft are the aluminum pieces? Can you scratch them with a finger nail? I'm guessing you're see bearing material. Although, I'm very surprised it would fail from the conditions you describe. For curiosity, what oil were you running?
So do u think its possible this ls3 could work? He doesnt care about the dry sump to much. Its a weekend cruiser anyways. Besides the dry sump engines are hard to find.
Is belt/pulley alignment the same, between the 2?? If its possible this engine could work i might start swapping it out monday!
So do u think its possible this ls3 could work? He doesnt care about the dry sump to much. Its a weekend cruiser anyways. Besides the dry sump engines are hard to find.
Is belt/pulley alignment the same, between the 2?? If its possible this engine could work i might start swapping it out monday!
ANYTHING will work, if you put the effort into it. Hell, put a 2JZ in the damn thing if you want.
The question becomes why? Just nut up and do a proper rebuild using the factory crank and new bearings and whatever else is necessary. If it's a "weekend cruiser" anyhow, then time shouldn't be a factor. Not that a GS is anything incredibly rare, but it does deserve to have the proper equipment installed.
If you're looking to make a buck on the sale of the used GS shortblock, whatever I guess. If you're using the proceeds from the GS shortblock sale to finance the LS3 replacement, then affording a Corvette probably isn't something appropriate.
I'm just failing to understand the "why put a wet sump in a GS" situation you have proposed. There has to be more to the story.
The story is, repairs will be covered under warranty. They are the ones tht ordered and shipped us the wet sump engine. We cant find a replacement dry sump engine. Ill try and talk to them and see if rebuilding the dry sump engine is a possibilitie. Warranty people normally try and just replace the engine.
when the original engine dropped a valve it messed up 2 lifters on the passenger side. They are stuck in the block and looks like one could have broken the block. We still havnt pulled the driver side head, and theres no tellin whats wrong with tht side.
Just seems easier to get/use a good low milage replacement.
Aren't factory bearings bi-metal (aluminum alloy & Steel backing)? You won't see copper. How soft are the aluminum pieces? Can you scratch them with a finger nail? I'm guessing you're see bearing material. Although, I'm very surprised it would fail from the conditions you describe. For curiosity, what oil were you running?
This is the only bad bearing I found. Main cap #4. Did not spin or cause any crank damage. I dont think this is where all of the oil pressure could have gone. I'm leaning towards a stuck bypass valve in the oil pump. Of course when I pulled the pulled the pump apart, It looked fine.
06-02-2018, 08:21 PM
Very low oil pressure Grand Sport LS3 
