What’s Up in the Forums: New LS3 Crate Motor Blows: GM’s Fault, or User Error?

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This three-month old LS3 crate motor failed after one ill fated track session. But is this just a warranty case or simply one big mistake on the owner’s part?

When you buy a brand spankin’ new engine, you generally expect it to last a while. That’s kind of the point of buying something new, after all. But that wasn’t exactly the case with LS1 Tech member pt2285‘s recent LS3 crate motor purchase. Not by a long shot. In fact, it took mere months to not only give him fits, but experience major failure!

“Blew my LS3 525 crate motor from Chevy. I’m never gonna buy another GM crate motor knowing what I know now. But check out these pictures because I thought I spun a bearing and that lead to oil starvation. But when I took it apart I saw this. How does this happen on a motor that’s 3 months old and ran at normal operating temp?”

Regular follows of the forums immediately recognized this particular motor and user from previous threads, however. And LLLosingit kicks off the investigation.

“Isn’t this the same engine where you had low oil pressure issues and 280+ oil temps? If that’s the case I would guess that would play a large part in the failure. Looking again at the gouges in the first picture, it definitely was the wrist pin that did the damage to the cylinder wall. As far as why the piston broke in the first place I have no idea. Probably not much of it left to do a good analysis.”


Some, including A.R. Shale Targa, believe this was more of a case of user error than GM’s fault.

“Saw this coming from your last thread. Your engine was damaged before from the high oil temps. Then you wrongly put a high volume pump in without having any more volume of oil. Your low idle pressure was a sign. The engine was begging you to tear it down and fix it. Now you have an expensive coffee table and are mad at GM. Your next engine will expire in a similar fashion unless you run a dry sump system. There’s even a pan mod for that to help scavenging for autocross type applications.”

To his credit, the OP admits that he made some errors in judgement here. Kinda.

“I’m not mad, I’m disappointed I guess. I didn’t everything the book says and even GM sells this motor as a competition motor. Looking back and knowing what I know (which is not a lot), I would never buy another GM crate motor again. For the price there are way better options. But I followed their guidelines and the **** blew.

I’m gonna try and warranty but odds are they will deny it. But at least I tried. As far the dry sump, I thought about it and I went wet instead. After talking to the racing guys there is no reason why you can’t use a wet sump for my application. I had a quality pan, the internal baffle, windage tray, etc. I was even running a little extra oil to help prevent sucking the pan dry.”

ColeGTO doesn’t bash the OP, however, taking more of an informative approach.

“I’d start by removing the rods and bearings, keeping them numbered. Look for damage, pitting, etc. Check the big end of the rods to see if they’re still round. Then I’d take a look at the main bearings and see if they tell any of the story. After that, I’d pull the pistons and rings to see what they look like and measure them. My guess is you’ll see some scored skirts and possibly some butted rings if it really got that hot.


The reason I asked about calibration was I’ve personally witnessed a brand new STOCK LS3 put a window through the block on the dyno after 50 pulls. All it took was one too many pulls with the slightest detonation down low (26 degrees of timing at 2,500 and WOT). 23 degrees is the max that it would really tolerate without pulling timing. No warning signs, noises, oil pressure, etc. Broke a piston and the rod made a window. Looked quite similar to your engine. Why one piston broke is because that’s all it takes to stop the engine. Had it been able to continue to run, I’m sure you would have seen more broken pistons.”

And yet, the debate rages on. Everyone has their theories as to what caused this LS3 to blow, and they also point fingers in a variety of directions. But we want to know what you think! Head over here to see the latest on this fascinating discussion, and be sure and add your educated thoughts to the conversation while you’re there!

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Brett Foote has been covering the automotive industry for over five years and is a longtime contributor to Internet Brands’ Auto Group sites, including Chevrolet Forum, Rennlist, and Ford Truck Enthusiasts, among other popular sites.

He has been an automotive enthusiast since the day he came into this world and rode home from the hospital in a first-gen Mustang, and he's been wrenching on them nearly as long.

In addition to his expertise writing about cars, trucks, motorcycles, and every other type of automobile, Brett had spent several years running parts for local auto dealerships.

You can follow along with his builds and various automotive shenanigans on Instagram: @bfoote.

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