Some 2019 F-Super Duty 176-inch wheelbase Crew Cab vehicles equipped with a 6.7L engine, a midship 48-gallon fuel tank, and built on 24-Jun-2018 and through 31-Aug-2018 may exhibit a whistle noise at the front of the fuel tank under the left hand side of the vehicle when the fuel level is 3/4 full or lower. This may be due to air moving through the front vapor valve fresh air vent tube during fuel fill, acceleration or braking. Follow the Service Procedure steps to correct the condition.
