Feds investigate 1.4M Honda V-6s for engine failure

The NHTSA last week announced an investigation into 1.4 million Honda and Acura vehicles for potential damage that could result in a complete failure of their 3.5-liter V-6 engines.

The bearings on connecting rods that connect the pistons with the crankshaft in certain V-6 engines can fail, causing catastrophic damage. The NHTSA’s Office of Defects Investigation (ODI) said it had received 173 reports from owners of this, including one that may have led to a crash or fire.

The investigation covers the following vehicles from Honda and its Acura luxury brand:

2016-2020 Acura MDX three-row crossover SUV

2018-2020 Acura TLX sedan

2016-2020 Honda Pilot three-row crossover SUV

2018-2020 Honda Odyssey minivan

2017-2019 Honda Ridgeline midsize pickup truck

An investigation is not the same as a recall, although it is part of the process the NHTSA goes through before asking an automaker to issue a recall. Until that happens, owners aren’t being asked to do anything.

The condition being investigated matches one that was the subject of a 2023 recall of nearly 250,000 cars, including many of the same models. However, the NHTSA said the specific population of vehicles covered under the investigation were outside the scope of that recall.

In the previous recall, Honda and the NHTSA concluded that the crank pins that attach the connecting rods to the crankshaft may have been improperly ground during production. This could allow rods to get loose or break, which could lead to pieces jamming themselves into cylinder heads or punching a hole through the engine block. That can be known as throwing a rod, and if it happens, the engine is ruined.