I had purchased a 2021 GMC Sierra equipped with the 6.2 liter motor in October of 2021. Within two weeks, my engine was experiencing problems. There was no service lights on the dash, and my truck suddenly shut off while on a busy road. I was able to coast to the side of the road, however it was a driving lane with no shoulder which made the situation dangerous. I was able to restart the engine after some time, and eventually get the vehicle off of the roadway, thankfully I got out of the driving lane without being struck by another vehicle. The truck had approximatley 1000 miles at this time and was brand new. I ended up needing a complete engine replacement due to failed crank bearings and connecting rods. I was told it was a crankshaft issue. After the complete motor replacement, sometime during the next year I was experiencing oil burning issues. On this second motor, a GM dealer had to completley rebuild the top end of the motor and install new piston rings. This is now a total of two motor failues in under 30,000 miles.