NHTSA Expands Investigation Into Nearly 1 Million GM Vehicles After Engines Fail Following Recall Repairs

August 24, 2026

GM engine failure investigation — Federal safety regulators have expanded an investigation involving GM’s 6.2-liter L87 V8 after receiving hundreds of complaints alleging engine failures following repairs under an earlier recall. Jonathan Weiss/Shutterstock

Federal safety regulators have escalated an investigation into General Motors after receiving hundreds of complaints alleging that 6.2-liter V8 engines failed even after vehicles received repairs under an earlier safety recall.

The National Highway Traffic Safety Administration opened Engineering Analysis EA26005 on August 20, 2026. The investigation concerns GM’s L87 6.2-liter V8 and encompasses approximately 997,743 vehicles from the 2021 through 2026 model years, according to NHTSA investigation data.

The issue is particularly notable because regulators are not simply investigating the defect that triggered the earlier recall. They are now examining reports that engines failed after owners had already taken their vehicles in for the prescribed remedy.

Why NHTSA Escalated the GM Engine Investigation

GM issued Recall 25V-274 to address potential engine failures involving certain L87 engines produced between March 1, 2021, and May 31, 2024. GM attributed the original problem to supplier manufacturing and quality issues.

Depending on the results of an inspection, the recall remedy involved either changing the engine oil viscosity or replacing the engine entirely.

NHTSA’s Office of Defects Investigation subsequently opened Recall Query RQ26001 in January 2026 to evaluate whether that remedy was working as intended. Regulators continued receiving allegations of failures after repairs, leading NHTSA to close the recall query and escalate the matter to the new Engineering Analysis.

An Engineering Analysis is an investigation, not a determination that GM vehicles have another safety defect or that a new recall is required.

Hundreds of Failures Were Reported After Recall Repairs

The numbers behind the investigation provide important context for GM owners.

NHTSA says its Office of Defects Investigation has received 499 complaints alleging post-remedy engine failure involving vehicles subject to Recall 25V-274. Of those, 473 involved vehicles that received the oil-viscosity remedy, while 26 involved vehicles that had received complete engine replacements.

GM reported receiving 6,953 complaints involving post-remedy engine failures, according to NHTSA’s investigation summary. The federal agency has also received 191 reports of L87 engine failures involving engines produced after the manufacturing period covered by the original recall.

That last group is important because NHTSA has now expanded its investigation beyond the engine-production window included in the previous recall.

Which GM Vehicles Are Under Investigation?

The investigation involves L87 6.2-liter V8 engines found in a number of popular Chevrolet, GMC and Cadillac trucks and SUVs.

Models identified in the investigation data include the Chevrolet Silverado 1500, Tahoe and Suburban; GMC Sierra 1500, Yukon and Yukon XL; and Cadillac Escalade and Escalade ESV. The broader investigation includes applicable vehicles from the 2021 through 2026 model years, although that does not mean every vehicle from every listed model year is affected.

Owners should check their specific vehicle rather than relying only on its model name or year.

Why Loss of Motive Power Is a Safety Concern

An engine failure can result in a loss of motive power, meaning the vehicle may no longer be able to propel itself normally.

That can create a potentially dangerous situation if a failure happens while merging onto a highway, crossing an intersection or traveling in heavy traffic. The original L87 investigation examined allegations of engine failures involving GM full-size trucks and SUVs, and the current investigation focuses specifically on failures occurring after the previous recall remedy.

Owners who experience an engine problem can also submit a vehicle-safety complaint to NHTSA. Consumer complaints are one of the sources the agency uses when reviewing potential safety defects.

What GM Owners Should Do Now

There is no newly announced recall associated with Engineering Analysis EA26005 at this stage, so owners should not assume the investigation means their vehicle automatically needs another repair.

However, anyone driving an applicable GM truck or SUV—particularly one that previously received work under Recall 25V-274—may want to keep documentation showing when and how the recall remedy was completed. Owners experiencing engine problems after a recall repair should contact their dealer and consider reporting the problem to NHTSA.

Consumers can use NHTSA’s recall and safety-issue search tools to check their vehicle and follow federal investigations. NHTSA also offers its SaferCar app, which can provide recall alerts after a vehicle’s VIN is entered.

Most importantly, EA26005 remains an open investigation. NHTSA has not yet concluded that another defect exists, and the investigation’s eventual findings will determine whether further action, including another recall, is warranted.