Federal auto-safety regulators have escalated an investigation into General Motors vehicles over engine-failure risks, expanding the probe to include newer model years after hundreds of additional complaints emerged.
The National Highway Traffic Safety Administration said on Friday that it has opened an engineering analysis covering an estimated 997,743 GM pickup trucks and SUVs from model years 2021 through 2026 powered by the L87 6.2-liter V8 engine.
The vehicles include the Chevrolet Silverado 1500, Tahoe, and Suburban; GMC Sierra 1500, Yukon, and Yukon XL; and Cadillac Escalade and Escalade ESV.
The investigation is examining both engines that failed after undergoing repairs under an earlier GM recall and those manufactured after the production period covered by that recall.
NHTSA said it has received 499 complaints alleging engine failures after vehicles had already received the recall remedy.
Of those, 473 involved vehicles that had received an oil-viscosity change, while 26 involved vehicles whose engines had been completely replaced.
The agency has also received 191 reports of failures involving L87 engines produced after the manufacturing period covered by the recall.
Overall, NHTSA has identified one crash and one injury among the incidents being investigated.
GM, meanwhile, reported receiving 6,953 complaints of post-remedy engine failures, according to the agency.
“The safety and satisfaction of our customers are the highest priorities for the entire GM team, and we continue to cooperate with NHTSA’s evaluation of this matter,” a spokesperson for the company said in a statement to The Epoch Times.
The latest action broadens a federal investigation that has been unfolding since early 2025.
NHTSA opened a preliminary evaluation on Jan. 16, 2025, after receiving reports of engine-bearing failures in GM trucks and SUVs equipped with the L87 engine.
GM subsequently issued a voluntary recall on April 24, 2025, covering 597,630 U.S. vehicles from model years 2021 through 2024 equipped with engines manufactured between March 1, 2021, and May 31, 2024.
GM said manufacturing defects in connecting rods and crankshafts could damage the engine and cause it to fail.
The automaker attributed the problems to supplier manufacturing and quality issues, including sediment in connecting rods and crankshaft oil galleries as well as crankshafts with dimensions or surface finishes that did not meet specifications.
Regulators Question Recall Remedy
As part of the recall remedy, owners were instructed to bring affected vehicles to GM dealerships for an engine inspection.
Engines that failed the inspection were replaced. Vehicles whose engines passed received higher-viscosity engine oil, along with a new oil-fill cap and oil filter.
GM also established special coverage for affected vehicles, extending warranty protection for 10 years or 150,000 miles from the vehicle’s in-service date, whichever came first.
But reports of engine failures continued after the recall work was completed.
On Jan. 16, 2026, NHTSA opened a recall query specifically to determine whether GM’s remedy was adequate.
At the time, regulators had received 36 complaints alleging that engines had failed after recall repairs.
GM has not expanded its existing recall. The nearly 998,000 vehicles cited by NHTSA represent the population under investigation, not a new recall.
The agency said the engineering analysis will continue examining post-recall engine failures and determine whether GM’s existing remedy is effective.
