GM Tried to Fix Its Troubled 6.2-Liter V8, Now Nearly 1 Million Vehicles Are Under Investigation

The L87 6.2-liter V8 engine found in many top-trim General Motors trucks and SUVs continues to give the automaker headaches after an earlier recall fix may not have worked. The National Highway Traffic Safety Administration announced today that it has opened a new investigation into the problematic motor after its Office of Defects Investigation reported receiving 499 complaints alleging post-recall remedy engine failure. L87 engines have been the subject of much scrutiny over the last year, with several owners suing GM for millions of dollars, culminating in one large lawsuit late in 2025. GM argued that the failure rate was only 3 percent, but even with thicker oil being provided as part of a recall, problems are still appearing.

Almost One Million GM Vehicles Under The NHTSA’s Spotlight

The ODI report says 2021-2026 GM vehicles equipped with the L87 engine are being investigated, affecting 997,743 vehicles. It also says that there has been at least one crash or fire, one incident of injury, and 6,050 incidents of engine failure in total. The incidents have been reported on both vehicles that received a higher-viscosity oil (473 complaints) and those that have had a complete engine replacement (26 complaints) under recall 25V-274, and the ODI has also received 191 reports of L87 engine failure in engines produced after the production period cited in the recall. GM says the issue comes down to manufacturing and quality shortcomings at its supplier, but whoever is to blame, it seems that GM still hasn’t quite figured out how to solve this problem.

Related: GM Finally Has a Fix for SUVs Stuck in First Gear, but More Models Are Affected

Hopefully, the ODI’s opening of an Engineering Analysis will help get to the bottom of this, but independent analysis suggests there are microscopic ridges on the L87 crankshaft, causing oil pressure to rise and fall dramatically, leading to tiny impacts on the connecting rod bearings, and ultimately, engine failure. That’s likely why GM thought thicker oil might help, but the L87’s tight clearances clearly demand a more focused approach. For the record, the engine is available in the following products:

• Chevrolet Silverado 1500
• Chevrolet Tahoe
• Chevrolet Suburban
• GMC Sierra 1500
• GMC Yukon
• GMC Yukon XL
• Cadillac Escalade
• Cadillac Escalade ESV

Autoblog’s Take

The L87 is on its way out, set to be replaced by a new Gen 6 small-block V8 related to the LS6 V8 in the new Chevy Corvette Grand Sport and Stingray, and GM is expected to move some manufacturing processes in-house to improve consistency and quality. The new engine will come in 5.7-liter and 6.6-liter forms and be supported by new investments in North American production, which should help improve reliability and thus reputation. We’ll experience it in new vehicles like the next-gen Silverado and Sierra, and while we doubt it’ll be as problematic as the L87, learning what causes the failures of the 6.2-liter motor will surely benefit everything GM makes going forward. Hopefully, those who have been affected will be fairly compensated.