Some 2008-2010 F-Super Duty 250-550 vehicle equipped with the 6.4L diesel engine may exhibit significant amounts of white smoke from the exhaust pipe while driving in high humidity or rainy conditions at temperatures above 40 degrees F. This smoke only appears during a moderate to full throttle tip-in that is performed after a period of steady-state driving.
Replace the charge air cooler (CAC) assembly with a new revised part, per workshop manual Section 303-12. Some white smoke may still be present under severe conditions even after the new CAC has been installed. This is considered a design characteristic of the charge air system and no further repair attempts should be made. According to Ford, the concern does not affect the life of the engine or exhaust components.
The revised charge air cooler is available under P/N 7C3Z-6K775-C.