The National Highway Traffic Safety Administration (NHTSA) is intensifying its investigation into Honda, probing over 1.4 million Honda and Acura vehicles following reports of severe engine issues. The inquiry, announced on November 6, 2023, aims to determine the extent of a defect that could lead to engine failure—an issue already responsible for the recall of nearly 250,000 Honda vehicles with 3.5-liter V6 engines last year. Here’s what owners and automotive enthusiasts need to know about this evolving situation.

Understanding the Issue: Engine Failure Risks

The central concern here is engine failure due to a crankshaft defect that can cause premature wear on the connecting rod bearings. This defect can potentially lead to the connecting rod seizing within the engine, resulting in sudden and complete engine failure. Such issues pose a safety risk, especially if an engine fails while the vehicle is in motion.

According to NHTSA, the issue appears to affect Honda’s and Acura’s popular 3.5-liter V6 engines found in a range of models from the 2016 to 2020 model years. Notably, the models under investigation include:

Acura MDX (2016-2020)
Acura TLX (2018-2020)
Honda Pilot (2016-2020)
Honda Ridgeline (2017-2019)
Honda Odyssey (2018-2020)

To date, NHTSA has received 173 reports of engine failure consistent with the crankshaft defect, leading the agency to explore whether the issue extends beyond the vehicles already recalled in 2023.

Honda’s Response and Background of the Issue

Honda was first alerted to the problem in 2020 and began a lengthy investigation. After identifying the defect as a manufacturing flaw, Honda issued a recall in November 2023 for 249,000 U.S. vehicles with the 3.5-liter V6 engine. This initial recall aimed to address engine failures by inspecting, repairing, or, if necessary, replacing the affected engines.

As part of the recall, Honda dealers have been tasked with inspecting engines in affected vehicles and performing necessary repairs. Honda has since reported approximately 1,450 warranty claims linked to the defect. However, not all vehicles displaying symptoms have been included in the initial recall, which has prompted NHTSA to launch this broader investigation to assess if more vehicles should be covered.

What NHTSA’s Investigation Entails

The NHTSA’s probe is a preliminary evaluation, which is often the first step in identifying whether an expanded recall is warranted. Through this investigation, the agency will assess the severity and frequency of engine failures in vehicles not yet covered by the recall. Given the potential safety implications, NHTSA will examine whether these additional models should be included and work with Honda to ensure affected consumers are notified and provided with appropriate remedies.

Honda’s Statement and Cooperation with NHTSA

On the day of the probe announcement, Honda confirmed it was aware of NHTSA’s investigation and stated it was actively cooperating with the agency. A representative for the automaker said, “Honda has already been in communication with the agency on this topic and will continue to cooperate with the NHTSA through the query process.” This cooperation suggests that Honda is prepared to work closely with NHTSA to understand the issue’s full scope and take corrective measures if needed.

What Owners Should Do Next

While the investigation unfolds, Honda and Acura owners of the affected model years should monitor any unusual engine behavior, such as odd noises, decreased performance, or warning lights related to the engine. If you experience symptoms of engine trouble, contact your dealer promptly to report the issue and explore available diagnostic or repair options.

For those who received a recall notice for the initial 249,000 vehicles covered, be sure to follow through with the inspection and any necessary repairs. Those whose vehicles were not included in the initial recall should keep an eye out for updates from NHTSA, as the investigation may lead to an expanded recall.