A growing number of owners are reporting catastrophic failures in GM’s 3.0-liter LZ0 Duramax diesel engine and while GM has issued a bulletin about the problem, there are questions on why no recall has been issued.
The engine is found in many popular models of GM vehicles like the Chevy Silverado 1500, GMC Sierra 1500, and full-size SUVs.
Catastrophic Engine Failure
The LZ0 Duramax, introduced as the successor to the LM2 engine, has earned praise for efficiency and torque. However, some 2025–2026 model-year vehicles equipped with the new LZ0 have reportedly suffered catastrophic “grenading” engine failures.
According to multiple reports from dealerships and technicians, the failures are linked to a defective thrust bearing that allows the crankshaft to move excessively inside the engine block. That movement can destroy internal components, leading to total engine failure.
GM Issues TSB, but No Recall
General Motors has issued Technical Service Bulletin (TSB) 25-NA-307, dated October 1, 2025, outlining inspection and diagnostic steps for technicians. The bulletin covers 2025–2026 Silverado, Sierra, Tahoe, Suburban, and Yukon models with the 3.0L LZ0 Duramax diesel.
The TSB instructs technicians to check for noises behind the bell housing and to look for diagnostic trouble code P06D, which can indicate insufficient crankshaft end play. If the crankshaft movement is out of tolerance, technicians are to inspect and repair the thrust surfaces.
However, because the TSB is not a recall, owners will not receive official notifications—leaving many unaware of potential problems. Even crazier is owner’s can pay for technicians to examine their crankshaft, yes really, but GM won’t recall the affected vehicles to examine them all.
What Owners Are Seeing and Hearing
Drivers have reported a low-oil-pressure warning light, engine noise from behind the bell housing, and in some cases, complete engine failure. Technicians recommend listening for knocking or rattling sounds near the bell housing and scanning for related error codes.
Dealerships can measure crankshaft end play using a dial indicator, though some owners may be charged diagnostic fees if their trucks are not yet showing symptoms.
Range of Impact and Owner Frustration
While the issue appears limited to vehicles built between early 2025 and late 2025, the full scope remains unclear. GM has not announced a stop-sale or formal recall, though reports from diesel mechanics suggest the problem may be more widespread than initially believed.
Truck owners have expressed frustration over the lack of public notification, comparing the issue to recent recalls affecting GM’s 6.2-liter or the ongoing lifter failures for the 5.3-liter V8 engines. Some are calling for a recall to inspect all affected crankshafts before more engines fail.
What Owners Should Do
Owners of 2025–2026 GM trucks or SUVs with the 3.0L LZ0 Duramax should:
- Listen for rattling or knocking near the bell housing.
- Scan for trouble code P06D or a low-oil-pressure warning.
- Keep detailed maintenance records and oil change receipts.
- Schedule a diagnostic inspection at a GM dealership if symptoms appear.
While GM continues to investigate, diesel owners should stay alert and keep a close watch for now on their trucks. The LZ0’s long-term reliability may hinge on how swiftly GM addresses what could become another costly engine controversy.
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