Owners and lessees of Kia Sorento sport-utility vehicles are suing the company over an alleged design defect that causes sudden engine failure.

The putative class action, filed Jan. 3 in federal court in Newark, alleges Kia has failed to repair the defect under warranty in 2002-09 Sorentos with the 3.5-liter, 24-valve DOHC V6 engine made by Hyundai.