Sources at one of Ford's engine plants told BlueOvalNews that Ford Motor Company has instructed assembly plants to stop shipping certain 2005 model year vehicles because they can contain defective 4.6L or 5.4L engines. The defective engines were manufactured by both the Windsor and Essex, Canada engine plants and were shipped to the following assembly plants: Michigan Truck, Kansas City Truck, Dearborn Truck, Norfolk Assembly, Kentucky Truck and Auto Alliance (Mustang).
The 2005 model year 4.6L and 5.4L engines in question were built with defective cylinder heads. According to sources, the defective cylinder heads will have an adverse effect on performance and will cause the engine to fail to meet Ford's specifications.
The products that can contain the defective engines include the 2005 Ford Mustang GT, 2005 F-Series, 2005 F-Series Super Duty, Ford Expedition and Lincoln Navigator. Ford has instructed the assembly plants to stop shipping vehicles until they are screened to see if they contain the defective engines.
It's not immediately clear if Ford will replace the entire engine at the assembly plant or just replace the defective cylinder heads and approve the vehicle for shipment to customers. At least one owner of a 2005 Mustang GT had their vehicle replaced due to a defective engine.