A U.S. auto safety regulator said on Friday it will open an investigation into about 454,840 Nissan vehicles over reports alleging engine failure that can lead to a loss of motive power with no ability to re-start.

The U.S. Office of Defects Investigation (ODI) has opened a preliminary evaluation into Nissan Rogue, Altima and Infiniti Qx50 vehicles, the National Highway Traffic Safety Administration said, adding a total of six complaints were received regarding the issue.

Vehicle owners reported engine failures, a loss of power, engine knocking noises, metal chunks and shavings found in the oil pan of certain vehicles equipped with the KR15DDT and KR20DDET engines, ODI said.

The Japanese automaker has looked to address main bearing and L-link damage or seizures on the engines by introducing multiple manufacturing process changes over time, the regulator said.

The investigation may be expanded if needed, ODI said.

(Reporting by Maria Ponnezhath and Nathan Gomes in Bengaluru; editing by Jason Neely and Sriraj Kalluvila)