The National Highway Traffic Safety Administration is expanding its probe into 286,000 General Motors vehicles in the U.S. over a possible engine failure issue, the safety regulator said on Monday, following several complaints, despite a recall.
The NHTSA said the issue stems from engine bearing failures in GM's L87 6.2-litre engine installed in models such as the Chevrolet Silverado 1500 and Cadillac Escalade.
The regulator opened a preliminary investigation into the issues in January, which led to a recall in April.
GM had said the connecting rod and crankshaft engine components may have manufacturing defects that can lead to engine damage or failure, boosting the risk of a crash.
The NHTSA on Monday upgraded the probe to an engineering analysis on the basis of 1,157 reports of engine bearing failure.
The regulator will also assess the potential safety-related issues of vehicles built outside the recall scope.