For owners who thought last year’s engine recall had settled the matter, a new federal investigation is raising uncomfortable questions. U.S. regulators have escalated their examination of General Motors’ 6.2-litre L87 V8 after receiving hundreds of complaints alleging engine failures even after recall repairs were completed.
The latest investigation covers 997,743 Chevrolet, GMC and Cadillac trucks and SUVs from the 2021 through 2026 model years. It does not mean nearly one million vehicles have just been recalled. Instead, regulators are examining whether the earlier remedy adequately addressed the problem and whether engines produced beyond the original recall window could face similar failures. For Canadian owners, the development matters because many of the same models and engines were also covered by a Transport Canada recall in 2025.
The New Investigation Covers 997,743 Vehicles
The National Highway Traffic Safety Administration’s Office of Defects Investigation opened Engineering Analysis EA26005 on August 20, 2026. Its scope encompasses 997,743 General Motors vehicles equipped with the naturally aspirated 6.2-litre L87 V8, making this substantially broader than the population covered by the original 2025 recall. Regulators are now examining vehicles spanning model years 2021 through 2026.
The distinction between an investigation and a recall is important. Owners should not interpret the 997,743 figure as confirmation that every vehicle involved needs a new repair. An engineering analysis allows investigators to gather technical information, study failure patterns and determine whether an existing remedy was sufficient. NHTSA can ultimately close an investigation without additional action, or the findings could contribute to another recall or revised repair program. For GM, the escalation means regulators still have unresolved questions about a problem the automaker had already attempted to address.
The 6.2-Litre L87 V8 Is at the Centre of the Case
The investigation concerns GM’s L87 6.2-litre gasoline V8, an engine offered in some of the company’s largest pickups and SUVs. Models within the investigation include the Chevrolet Silverado 1500, Tahoe and Suburban; GMC Sierra 1500, Yukon and Yukon XL; and Cadillac Escalade and Escalade ESV. The investigation is specific to vehicles equipped with the L87 rather than every example of those nameplates.
That matters for shoppers and owners because a Silverado or Yukon badge alone does not establish whether a particular vehicle is involved. These models have been sold with several different powertrains, including smaller gasoline engines and diesel options. The L87 has been particularly important in higher-powered versions of GM’s full-size trucks and SUVs, where customers frequently use the vehicles for towing, highway travel and family transportation. A sudden engine shutdown in those settings presents more than an inconvenience because the central concern identified by regulators is loss of propulsion while the vehicle is being driven.
GM Had Already Recalled Nearly 600,000 U.S. Vehicles
The latest action builds on a major recall announced in April 2025. GM recalled 597,630 U.S. vehicles from the 2021 through 2024 model years equipped with the affected L87 engine. The company’s manufacturing analysis focused on engines produced from March 1, 2021, through May 31, 2024, a period during which GM found an elevated rate of potentially related engine failures.
The original recall followed a NHTSA investigation and years of internal GM reviews. The automaker said it had previously investigated the condition in 2022, 2023 and 2024 before opening another product investigation in January 2025. By April, GM’s safety organization had decided a recall was necessary. The recalled U.S. population included more than 153,000 GMC Sierra 1500s, roughly 107,000 Chevrolet Silverado 1500s and tens of thousands of Escalades, Tahoes, Suburbans and Yukons. That scale made the L87 issue one of GM’s most significant recent engine-related safety actions.
Manufacturing Problems Were Linked to Internal Engine Components
GM’s filings identified supplier manufacturing and quality problems involving critical components inside the engine. Investigators found evidence of sediment affecting connecting rods and crankshaft oil galleries, along with crankshafts that could have dimensions or surface finishes outside specification. Those conditions could contribute to bearing damage, eventually resulting in severe internal engine problems and loss of propulsion.
The mechanical details help explain why the matter has received sustained regulatory attention. Connecting rods, bearings and crankshafts operate under enormous loads, and damage in these areas can progress from abnormal noises to an engine that can no longer operate. Transport Canada similarly warned that affected vehicles could produce unusual engine sounds or illuminate a warning light before failure. GM said manufacturing improvements affecting connecting rods and crankshafts had been implemented by June 1, 2024. The fresh investigation is significant partly because regulators are now studying reports involving engines manufactured after that original suspect production period.
The Recall Remedy Did Not Mean Every Engine Was Replaced
When the 2025 recall began, dealers were instructed to inspect affected engines and determine the appropriate remedy. Vehicles that failed the inspection could receive engine repair or replacement. Vehicles that passed were given higher-viscosity engine oil, along with a replacement oil filter, a different oil-fill cap and documentation reflecting the change. Canadian recall instructions described essentially the same corrective approach.
That split remedy is now central to the new investigation. An owner who visited a dealership under the recall could therefore leave with the original engine still installed if it passed GM’s inspection procedure. This was not an unofficial dealer decision; it was part of the formal recall remedy. At the time, GM estimated that roughly 3% of the recalled U.S. population could contain the defect. The continuing complaints have prompted regulators to ask whether the inspection and higher-viscosity-oil remedy reliably identified and protected engines that might later experience internal damage.
Regulators Have Received 499 Post-Repair Failure Complaints
NHTSA says it has now received 499 complaints alleging an engine failure after the recall remedy had already been completed. Of those cases, 473 involved vehicles that received the higher-viscosity-oil remedy. Another 26 complaints involved vehicles whose engines had been completely replaced before another alleged engine failure occurred. Those numbers are a major reason the earlier recall review has escalated into an engineering analysis.
GM’s own data set is considerably larger. According to the regulator’s investigation summary, the automaker reported receiving 6,953 complaints of post-remedy engine failure. Regulatory complaint totals and manufacturer records are not necessarily directly comparable because the databases can include different reports, definitions and duplicate submissions. Even so, the volume gives investigators substantially more information to study than was available when the recall query began. NHTSA initially opened a recall-query investigation in January 2026 after receiving 36 owner complaints alleging failures after completed recall work.
Another 191 Reports Point Beyond the Original Recall Window
One of the most consequential developments involves engines that were not included in the original manufacturing window. NHTSA says it has received another 191 reports involving L87 engine failures in engines produced after the period identified in Recall 25V-274. The original recall focused on production from March 1, 2021, through May 31, 2024. The engineering analysis now expands the investigation beyond that cutoff.
That does not establish that newer engines contain the same defect, and it does not mean every 2025 or 2026 vehicle equipped with an L87 is defective. It does mean regulators believe the newer reports deserve additional examination rather than being treated as unrelated incidents. This is one reason the investigation population reaches the 2026 model year even though the earlier recall involved 2021-2024 vehicles. Investigators will need to determine whether the post-May 2024 failures share the same underlying causes, represent different problems, or indicate that earlier manufacturing changes did not fully eliminate the risk.
The Earlier Investigation Already Contained Thousands of Failure Reports
The background to the recall was substantial even before the latest 499 complaints emerged. GM told NHTSA that its investigation had identified 28,102 U.S. field complaints or incidents potentially connected to L87 crankshaft, connecting-rod or engine-bearing failures. Of those, 14,332 involved allegations of loss of propulsion. The reports covered a period extending from April 2021 through early February 2025.
GM also identified 12 potentially related alleged crashes and 12 potentially related alleged injuries in the United States. Its filing characterized the specifically alleged injuries as minor or non-physical and noted that most were not crash-related. The automaker additionally identified 42 potentially related fire allegations, while cautioning that causation was unclear in most cases and that some engine-compartment damage could occur as a consequence of an engine failure itself. These historical numbers should not be confused with the 499 post-remedy complaints driving the latest investigation; they describe the broader record preceding the original recall.
Canadian Owners Were Already Included in a Separate Recall
The earlier L87 problem was not confined to vehicles sold in the United States. Transport Canada issued Recall 2025225 in April 2025 covering certain 2021-2024 Cadillac Escalade and Escalade ESV, Chevrolet Silverado, Tahoe and Suburban, and GMC Sierra, Yukon and Yukon XL vehicles equipped with the 6.2-litre V8. Canadian recall databases list 49,848 vehicles as affected by that campaign.
Transport Canada warned that improperly manufactured connecting rods or crankshaft components could produce abnormal noises or a warning light and could ultimately cause the engine to fail. The agency described sudden loss of power to the wheels as a potential crash risk. The latest NHTSA engineering analysis, however, is a U.S. regulatory investigation and should not be described as a new Canadian recall. Canadian owners concerned about an L87-powered vehicle should check the vehicle identification number against Canadian recall information and GM records rather than assuming that the broader U.S. investigation automatically changes their vehicle’s recall status.
Owners Should Watch the Investigation, Not Assume the Outcome
For now, owners are dealing with an open investigation rather than a newly announced remedy. NHTSA says an engineering analysis is used when investigators need more detailed information, technical evaluation or testing before deciding whether a safety defect warrants additional action. The agency says it generally aims to complete engineering analyses within 18 months, although individual investigations can develop differently depending on the evidence.
Owners of previously recalled vehicles should confirm that outstanding recall work has been completed and retain service documentation showing what remedy was performed. Those who experience abnormal engine noises, warning lights, reduced performance or other symptoms identified in recall materials have strong reason to contact a GM dealership promptly. U.S. consumers can also file safety complaints with NHTSA, while Canadians can report safety concerns through Transport Canada. GM has said customer safety and satisfaction remain priorities and that it continues cooperating with NHTSA. The unanswered question is whether the existing repair strategy will ultimately satisfy regulators.
