First off, I am not here to "rant" and add my own emotions. I am giving you the straight facts and nothing more. If you're looking for a drama, keep on scrolling.
My 2026 GMC AT4 with the LZ0 Duramax had 3690 miles when the engine basically destroyed itself. There is about a 6-month window when these trucks were built that have faulty engines. It was approximately May-Sept 2025 BUILD if I remember correctly. My truck was built in July 2025. My truck went into reduced acceleration mode and gave fault code P06DD. I have a Banks iDash that will show the fault code. After this happened, I could hear metal/metal noise coming from the bottom of the engine at the back. My suspicion is this as the well-known thrust bearing failure. It had to obviously be towed to a dealership. The service advisor told me something at the back of the crankshaft gave out. That would align with everything I've been reading. When it happened, I actually felt/heard something in the engine go. It was not a gradual failure. The truck went from driving like a dream to a nightmare instantly. There were no warning signs of any kind. If you are looking at buying a GM truck with this LZ0 motor, check the build date on the doorjamb sticker. My wife has a friend who's grandson had this exact same failure recently. This is not a small problem. I suspect GM is replacing a lot of engines right now. I was told the engine is "indefinitely" on back order.
A D V E R T I S E M E N T S
First off, I am not here to "rant" and add my own emotions. I am giving you the straight facts and nothing more. If you're looking for a drama, keep on scrolling.
My 2026 GMC AT4 with the LZ0 Duramax had 3690 miles when the engine basically destroyed itself. There is about a 6-month window when these trucks were built that have faulty engines. It was approximately May-Sept 2025 BUILD if I remember correctly. My truck was built in July 2025. My truck went into reduced acceleration mode and gave fault code P06DD. I have a Banks iDash that will show the fault code. After this happened, I could hear metal/metal noise coming from the bottom of the engine at the back. My suspicion is this as the well-known thrust bearing failure. It had to obviously be towed to a dealership. The service advisor told me something at the back of the crankshaft gave out. That would align with everything I've been reading. When it happened, I actually felt/heard something in the engine go. It was not a gradual failure. The truck went from driving like a dream to a nightmare instantly. There were no warning signs of any kind. If you are looking at buying a GM truck with this LZ0 motor, check the build date on the doorjamb sticker. My wife has a friend who's grandson had this exact same failure recently. This is not a small problem. I suspect GM is replacing a lot of engines right now. I was told the engine is "indefinitely" on back order.
- Dennis E., Montgomery, TX, US