Federal investigators reopened a GM V8 case because the recall fix did not stop the failures

Federal safety investigators have reopened their scrutiny of General Motors’ 6.2-litre V8 engine, this time because the fix from last year’s recall does not appear to have solved the underlying problem. The National Highway Traffic Safety Administration’s Office of Defects Investigation opened a new Engineering Analysis on August 20, 2026, covering nearly a million GM trucks and SUVs equipped with the engine, after regulators kept receiving reports of engine failure in vehicles that had already been through the recall repair.

The engine at the center of the case, known internally as the L87, sits under the hood of some of GM’s best-selling trucks and full-size SUVs. The new investigation does not undo the original recall, but it signals that federal regulators are not satisfied the repair GM issued actually stopped the failures it was meant to fix.

A Second NHTSA Probe After the First Recall’s Fix Fell Short

The new case, designated EA26005, grew out of an earlier Recall Query that NHTSA opened on January 16, 2026, specifically to assess how well GM’s 2025 recall repair was working. According to NHTSA’s opening resume for the investigation, the agency kept receiving complaints of engine failure in vehicles after the recall remedy had already been completed, whatever form that remedy took, and decided the pattern warranted a full Engineering Analysis rather than the earlier, narrower review. The resume lists the case’s status as an open action.

Rod-Bearing Damage and Out-of-Spec Crankshafts Behind the Original Recall

The problem traces back to Recall 25V-274, which GM filed in 2025 after an internal teardown of failed engines. GM’s own recall report attributes the defect to two supplier manufacturing and quality issues: rod-bearing damage caused by sediment left on connecting rods and inside crankshaft oil galleries, and crankshaft dimensions and surface finishes that fell outside specification. GM traced the affected parts to engines built between March 1, 2021, and May 31, 2024, and said a series of manufacturing improvements made on or before June 1, 2024, addressed the contamination and quality issues going forward.

Two Repair Paths, and Reports of Failure After Both

GM’s recall remedy sent every affected vehicle through a dealer inspection. Engines already showing damage were repaired or replaced outright; engines that passed inspection instead received a higher-viscosity oil, along with a new oil fill cap, an oil filter change and an insert added to the owner’s manual. NHTSA’s new investigation shows failures kept surfacing regardless of which repair a vehicle received: of 499 complaints alleging engine failure after the recall remedy, 473 came from vehicles that got the oil change and 26 came from vehicles that had already received a full engine replacement.

Engines Built After the Recall’s Cutoff Are Now Also Under Scrutiny

Beyond the post-repair failures, NHTSA said it has received 191 reports of L87 engine failures in engines built after May 31, 2024, the cutoff date the original recall used to define which vehicles were affected. Because those newer engines fall outside the population GM recalled, the agency expanded EA26005’s scope to include them, effectively asking whether the manufacturing problems GM said it fixed in production actually stopped when GM said they did. GM has told regulators it received 6,953 complaints of post-remedy engine failure, compared with 690 complaints reported directly to NHTSA’s own database.

The Warning Signs Tied to a Failing L87

The recall report’s chronology shows GM had looked at this problem before and moved on. GM closed three earlier internal product investigations into L87 engine failures, in February 2022, June 2023 and July 2024, each time based on the safety field information available at the time. It was only after NHTSA notified GM of its own inquiry, in January 2025, that GM reopened the matter, reviewed teardown data from failed field engines alongside a study of new, unused crankshafts, and identified the manufacturing defects behind the eventual recall. By that point, GM’s own investigation had identified 28,102 field complaints or incidents potentially related to crankshaft, connecting rod or bearing failure, including 14,332 that specifically alleged a loss of propulsion, along with 12 potentially related crashes and 42 potentially related fire allegations.

GM’s recall paperwork lists the symptoms owners may notice before an engine fails outright: knocking, banging or other unusual engine noises, an illuminated check-engine light, and performance problems such as hesitation, unusually high RPMs, abnormal shifting, reduced propulsion or a no-start condition. NHTSA’s resume for the new investigation records one crash, one fire and one injury among the complaints filed with the agency so far, though the great majority of the reports describe lost power rather than a collision.

Which GM Trucks and SUVs Carry the L87 V8

The engine appears across GM’s largest vehicles. The Chevrolet Silverado 1500, Suburban and Tahoe, the GMC Sierra 1500, Yukon and Yukon XL, and the Cadillac Escalade and Escalade ESV were all named in the original recall, which covered roughly 597,600 vehicles from the 2021 through 2024 model years. NHTSA’s newly opened Engineering Analysis covers a larger population still, 997,743 vehicles spanning the 2021 through 2026 model years, reflecting both the original recall population and the newer, later-built engines regulators are now also examining.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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