The National Highway Traffic Safety Administration said on Monday that some older Ford cars and SUVs pose unreasonable safety risks because the timing belt may fail and cause them to lose power or engines to seize. The U.S. auto safety regulator upgraded a defect investigation into about 135,000 Ford Fiesta, Ford Focus and Ford EcoSport vehicles with 1.0L engines from various model years between 2014 and 2021. NHTSA said its initial probe found timing belt material may degrade and create debris clogging the mesh oil pump pick-up screen, resulting in reduced engine oil pressure. Some drivers reported engine failures costing thousands of dollars to fix. Ford is offering reimbursement to eligible customers who previously paid for engine repairs or replacement due to a timing belt-related issue, NHTSA added.