Honda Engine Investigation: What 1.4 Million Owners Need to Know

When Reliable Engines Go Rogue

The National Highway Traffic Safety Administration (NHTSA) has launched an investigation into Honda and Acura vehicles over serious engine failures with the 3.5-liter V6 SOHC VTEC motor. After over 400 complaints about failing connecting rod bearings, federal investigators are questioning whether Honda's previous recall for similar defects was comprehensive enough.

Related: Honda, Acura Accused of ‘Start-Stop Engine Failure’ Affecting up to 2.2 Million Vehicles

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.

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Honda's Fix: Too Little, Too Late?

The probe targets popular models including 2016-2020 Honda Pilot, 2018-2020 Honda Odyssey, 2016-2020 Acura MDX, 2018-2020 Acura TLX, and 2017-2019 Honda Ridgeline. The connecting rod bearing failures can cause complete engine failure.

We reached out to Honda regarding the preliminary evaluation, and were told that:

"Honda is committed to safety. We are aware that NHTSA has closed an existing Recall Query (RQ24013) and opened a Preliminary Evaluation (PE25008), which addresses complaints that a failure of connecting rod bearings could lead to engine failure in certain 2016-2020 Acura MDX, 2018-2020 Acura TLX, 2016-2020 Honda Pilot, 2017-2019 Honda Ridgeline and 2018-2020 Honda Odyssey vehicles.

Honda has already been in communication with the agency on this topic and will continue to cooperate with NHTSA as the investigation continues."

Honda's recall solution involved replacing affected engines or components where crankshaft manufacturing defects were present. The automaker blamed improper equipment settings during production that resulted in connecting rod journal dimensions being out of specifications.

Since that recall, the NHTSA has decided to look into over 400 complaints of a similar nature, including seven reports of crashes or fires. The Office of Defects Investigation has noted that the subject engine failures are not caused by the crankshaft manufacturing defect addressed by Honda in the previous recall. Honda denied coverage for 173 newer complaints despite similar symptoms, suggesting the original recall scope was too narrow.

When Honda Warranties Won't Cover the Damage

Honda owners facing engine failure have several options beyond warranty coverage. File complaints with NHTSA to support the ongoing investigation. For affected vehicle owners, start by checking the official recall website to see if your vehicle was included. Document any engine symptoms like unusual noises, rough idling, or performance issues.

Class-action lawsuits may emerge, potentially providing additional compensation for affected owners. The NHTSA probe represents a critical moment for Honda's reliability reputation that's already taken a hit in recent years, and owners should be taking proactive steps to protect themselves.

This story was originally reported by Autoblog on Aug 25, 2025, where it first appeared in the News section. Add Autoblog as a Preferred Source by clicking here.