(Reuters) -The National Highway Traffic Safety Administration said it had opened an audit into 137,256 Kia America vehicles on Friday to assess the effectiveness of the automaker's remedy for defective piston oil rings in some Seltos and Soul models.

In February, Kia America launched a recall of the said Seltos and Soul vehicles, model year 2021-2023, over concerns that piston oil rings may have been manufactured incorrectly, which can result in engine damage causing a loss of motive power or an increased fire risk.

The auto safety regulator said its Office of Defect Investigation's recall division reviewed complaints that allege ineffectiveness and unavailability of recall remedy, as well as inconsistency in inspection results.

The audit query will look into Kia's remedy measures in view of the 47 complaints received from April 29 through June 27, this year.