For the record, this isn't the worst damage we've seen from an I Do Cars engine teardown video. It's not even the worst 3.0-liter Duramax we've seen, lest we forget the destroyed diesel that literally had valve shapes stamped into the pistons. But we've never seen a hole in the cylinder caused purely by heat. How hot does it have to get to actually burn through a cylinder bore?
We can tell you it's hotter than the melting point of aluminum. Three of the six aluminum pistons in this engine were hot enough to melt at least a little bit, but one was so much worse than the rest. You don't get a proper sense of the destruction until it's freed from the block, which wasn't easy because the engine was completely locked up. Pistons were stuck in the cylinders, and a main bearing was essentially fused to the crankshaft.
So what happened? Something caused the inner cylinders to get insanely hot. On the worst of the bunch, things got hot enough to torch a hole in the cylinder bore. Bits of solid and molten aluminum reached the bottom end, partially blocking an oil passage which caused the aforementioned main bearing to fuse to the crankshaft. And it happened to an engine from a 2020 Chevrolet Silverado 1500 with just 45,000 miles on it.
That's what happened, but how did it all begin? A fuel problem is the likely source, but it's not quite as simple as that. Apparently, the engine wasn't replaced under Chevrolet's five-year/60,000-mile powertrain warranty. This isn't confirmed, but evidence presented in the video strongly points in that direction. If true, that would suggest some kind of user error led to the Duramax's destruction.
Was it running an aftermarket tune? Possibly, but the video hedges towards gasoline being accidentally filled into the truck's tank. Such an error could cause intense heat, and it explains why it wouldn't be covered under warranty. But without any confirmation from the engine's former owner, it remains just a theory.
In any case, pay attention at the pump. A mixup between gas and diesel can be a very costly mistake.
