Reports of engine problems involving some older Honda and Acura vehicles spur probe by the National Highway Traffic Safety Administration.

The National Highway Traffic Safety Administration’s Office of Defects Investigation is looking into thousands of engine failures in an assortment of Acura and Honda vehicles. This includes the Acura TLX and MDX as well as the Honda Pilot, Odyssey, and Ridgeline.

Honda’s November 2023 recall addressed 249,000 vehicles with crankshaft manufacturing defects that could cause total engine failure or even underhood fires. If this investigation leads to a recall, Honda could be looking at investigating over 1.4 million engines, and that’s just in the U.S.