The U.S. government’s highway safety agency is investigating complaints that engines can fail on as many as 1.4 million Honda and Acura vehicles.

The probe by the National Highway Traffic Safety Administration covers the 2016 through 2020 Honda Pilot and Acura MDX, as well as the 2018 through 2020 Honda Odyssey and Acura TLX. Also included is the 2017 through 2019 Honda Ridgeline.

The agency says in documents posted on its website Monday that connecting rod bearings on vehicles with 3.5-liter V6 engines can fail, leading to complete engine failure. Connecting rods link the pistons to the crankshaft and convert vertical motion to move the wheels.

Honda recalled about 250,000 vehicles in November of 2023 to fix the same problem. But the agency says it has 173 complaints from owners who reported connecting rod bearing failures, yet their vehicles weren’t included in the recall. One owner reported a crash with no injuries.

The agency said it’s opening a recall query to determine the severity of the problem in vehicles not included in the 2023 recall.

Honda said it will cooperate with NHTSA on the investigation.

In documents explaining the 2023 recall, the automaker said had 1,450 warranty claims due to the bearing problem but no reports of injuries. Dealers were to inspect and repair or replace the engines if needed.