U.S. auto safety regulators have opened an investigation into complaints that General Motors vehicles equipped with certain V8 engines, including its best-selling Silverado, can seize up without warning.

The ODI currently investigates L87 engine failures in 2019 through 2024 trucks and sport utility vehicles from the Chevy, GMC, and Caddy brands

The National Highway Traffic Safety Administration’s Office of Defects Investigation has begun looking into engine failures involving an estimated 877,710 vehicles from GM. The vehicles are full-sized trucks and SUVs equipped with the 6.2-liter L87 V8 engine.

Complaints received by the agency allege a bearing failure that may result in either an engine seizure or a breaching of the engine block. GM said it is cooperating with the agency.

US auto safety regulators are probing General Motors Co. over concerns that more than 870,000 of its full-size pickup trucks and SUVs face the risk of engine failure.