Ford offers 10-year warranty as EcoBoost engine-failure probe ends

It began in July 2022 as regulators started looking into reports of engine failures affecting 2021 Bronco SUVs. It then turned into a two-year probe covering more than 411,000 vehicles outfitted with Ford’s EcoBoost engines, including the Ford F-150 Bronco, Edge and Explorer, as well as the Lincoln Aviator and Nautilus.

And now, the verdict is in.

The National Highway Traffic Safety Administration closed the probe after Ford agreed to check potentially affected engines and give owners an extended warranty.

NHTSA and Ford’s own inspectors confirmed that the issue came from a faulty intake valve that could drop inside the EcoBoost engine, causing it to lose power or shut down. The agency’s forensic analysis found the defective valves would fracture when exposed to high temperatures during regular engine use. The faulty valves were made between May and October 2021, NHTSA said.

A subsequent change in the manufacturing of the valves eliminated most of the potentially at-risk engines and vehicles studied by the NHTSA probe.

Ford, meanwhile, said that not all valves manufactured during the 2021 period were faulty and that half of the failures happened before affected vehicles were driven for 5,000 miles. Most of the remaining failures occurred before vehicles were driven for 20,000 miles.

In August, Ford recalled 90,000 vehicles, offering a dealer inspection and a test to identify whether these contained the defective valves. These included Bronco, Explorer, Edge, F-150, Aviator and Nautilus models. The F-150 was the most potentially affected model, with close to 48,000 vehicles recalled.

But given that Ford estimates most faulty-valve engines had already failed, it did not commit to replacing engines. Instead, it agreed to provide an extended powertrain warranty covering up to 10 years or 150,000 miles, whichever comes first.

Ford says its EcoBoost engine provides a powerful performance with better fuel economy than most conventional engines. The EcoBoost’s turbocharger uses the force of the exhaust to push more air into the engine, avoiding the loss of energy in the exhaust, Ford says.