DETROIT– The U.S. government’s auto safety regulator has ended a two-and-a-half-year investigation into engine failures at Ford after the company replaced engines or extended warranties on some vehicles.
This was reported by the National Highway Traffic Safety Administration documents posted Monday on its website that its analysis traced the problem to intake valves that could break inside some 2.7-liter and 3-liter turbo engines.
Documents say the investigation opened in May 2022 ultimately included more than 411,000 vehicles from the 2021 and 2022 model years, including the Ford F-150 Bronco, Edge and Explorer, as well as the Lincoln Aviator and Nautilus.
The agency investigated catastrophic engine failures caused by intake valves breaking, falling into the cylinder and hitting the piston.
The documents show that a forensic analysis of broken valves found that when they were made by a parts supplier, the temperature became too high, making them brittle and likely to break under normal engine use.
An analysis of data from the outage report showed that the defective valves were manufactured between May and October 2021, the agency said. Ford claimed that not all valves produced during this period were defective and that a large majority of the failures occurred before the vehicles had been driven 20,000 miles.
A statistical analysis by the agency to predict the number of failures, and an analysis of the failure reports “are generally consistent” with Ford’s finding that the valves would fail at low mileage, and the majority of vehicles with defective valves “has already experienced an outage,” the agency said.
Earlier this year, Ford recalled approximately 91,000 vehicles whose valves were manufactured during the suspect period. They are tested and, if necessary, receive a new engine. The company also extended the warranty on valved vehicles made during that period to 10 years or 150,000 miles, the documents said.
During the investigation, the agency said it found 396 customer complaints, 825 warranty claims and 936 engine replacements. No accidents or injuries have been reported.