The National Highway Traffic Safety Administration’s Bureau of Defect Investigation opened an investigation into Honda Motor Co. after receiving numerous reports of engine failures.
The investigation covers about 1.4 million Honda vehicles produced between 2016 and 2020 and comes after the agency received 173 reports of connecting rod bearing failures on vehicles equipped with six-cylinder engines.
Vehicles under investigation include the 2016-2020 Honda Pilot SUV, 2018-2019 Honda Odyssey minivan, 2017-2019 Honda Ridgeline pickup, as well as the brand’s 2018-2020 Acura TLX sedan and 2016-2020 Acura MDX SUV. luxury from the car manufacturer. These vehicles were also included in a November 2023 recall for the same engine problems.
The NHTSA investigation into engine failures, opened Nov. 8, will evaluate the scope of last year’s recall and the severity of the alleged defect in other Honda vehicles that were not included in it. According to the NHTSA report, all 173 owner questionnaires received had “characteristics consistent with the previous recall,” but were deemed “out of its scope.”
According to a service bulletin sent to U.S. Acura dealers in February, Honda cited improper settings of the equipment used to produce the V6 engine’s crankshaft, resulting in an out-of-spec crankpin size. Defect in workmanship can cause increased friction between the journals and bearings, which can cause them to seize and cause serious engine damage, as well as increasing the risk of fire, accident or injury.
Last year’s recall included about 248,999 Honda vehicles equipped with V6 engines, but only 1 percent were estimated to have the defect. According to the NHTSA, Honda received 1,450 warranty claims for engine failures, but no reports of injuries from July 2014 to Nov. 3, 2023.
Honda has been informed of the potential engine problem in November 2020 and continued to analyze and investigate the issue through February 2022. Manufacturing equipment setup and inspection processes were enhanced in 2020 to ensure engine crankshaft journals were manufactured within proper tolerances, according to NHTSA’s 2023 recall report.
In April 2022, Honda started a detailed analysis of the issue, focusing on different crankshaft bearing specifications.
In February 2023, Honda expanded its investigation to vehicles that had not experienced engine problems to conduct a comparative analysis. On November 2, 2023, the automaker determined that an engine defect was still present and decided to carry out the recall last year.
It is unclear how long the current NHTSA probe will take to complete. But if the agency determines that an engine defect is present in some or all of the 1.4 million vehicles, it could lead to a recall and increased warranty costs for Honda.