GM 6.2L V8 engine failures are raising a new question among owners of older Chevrolet Silverado and GMC Sierra pickups: Could the problems involving the newer L87 reach back to the L86 used in the 2014-2018 trucks?
A new report by Zane Merva at GM-Trucks.com brings that question into focus. But the proposed connection remains unverified. Federal recall documents identify manufacturing problems in certain L87 engines. They do not establish that those defects extend to the older L86.
Why L86 owners are asking
GM-Trucks.com reports that a forum member described a video claiming some L86 engines built in late 2017 and 2018 used a rod bearing similar to an uncoated bearing discussed in connection with L87 failures.
That is a secondhand claim. GM-Trucks.com says it could not locate the video or verify the connection. The outlet also says it has asked General Motors about the alleged bearing similarity and will update its reporting with any response.
The distinction matters for owners: A question about shared parts is not confirmation of a shared manufacturing defect. The report does not establish which original-production bearings were installed in which L86 engines, or demonstrate that an L86 failed from the defects GM identified in the L87 recall.
What GM documented about L87 failures
GM’s federal filing for recall 25V274 identifies two causes found through engine teardown analysis: sediment on connecting rods and in crankshaft oil galleries that damaged rod bearings, and crankshafts whose dimensions and surface finish did not meet specifications.
GM attributed those problems to supplier manufacturing and quality issues. The filing says they can cause or contribute to bearing damage, engine failure and loss of propulsion, increasing crash risk.
The recall covers certain 2021-2024 trucks and SUVs with the L87, using a suspect manufacturing window of March 1, 2021, through May 31, 2024. The July 2025 filing lists 597,571 potentially involved vehicles. It specifically excludes vehicles outside that window and those with other engines.
Dealers inspect affected engines and repair or replace them as needed. Vehicles that pass receive higher-viscosity oil, a new filter and oil-fill cap, and an owner’s manual insert.
What the documents do not prove about L86
The recall’s findings concern the L87 population GM identified. They do not verify the circulating L86 bearing claim, identify an affected L86 production period or confirm that older engines have the same contamination or crankshaft defects. GM has not confirmed an L86 connection in the documents reviewed for this story.
Nor does the filing reduce the L87 problem to whether a bearing has a coating. Its stated causes involve contamination and crankshaft manufacturing specifications. A claim about bearing similarity cannot, by itself, bridge that evidentiary gap.
PUTT’s coverage of two independent L87 teardowns examines bearing distress and questions about machining and lubrication. Those examinations concern L87 engines. They do not establish a failure pattern in the L86.
The newer engine remains under investigation
The federal inquiry has continued beyond the original recall. The National Highway Traffic Safety Administration opened engineering analysis EA26005 on Aug. 20, covering an estimated 997,743 vehicles from the 2021-2026 model years equipped with the L87.
The agency reported 499 complaints alleging engine failure after the recall remedy and another 191 involving L87 engines produced after the recall’s manufacturing window. Investigators are examining remedy effectiveness and later-production failures. That expanded scope still does not include the older L86.
Our report on the recall-remedy investigation explains that development. PUTT also covered the original federal L87 engine-failure probe.
What would establish an older-engine connection?
Answering the L86 question would require evidence tying specific engines and their original components to a documented failure mechanism. Relevant evidence could include production records, identified bearing specifications and teardown measurements compared with GM’s specifications.
For now, the GM-Trucks.com report raises an owner question, not a confirmed extension of GM’s L87 defects. Owners checking recall coverage can use their VIN through NHTSA’s recall lookup or their dealer. An engine problem should be documented by its diagnosis, mileage and repair history rather than assumed to match another engine’s failure.
