The National Highway Traffic Safety Administration (NHTSA) has closed their investigation into engine problems in the 2011-13 F-150 after Ford sent a technical service bulletin to dealers on how to fix the problem. NHTSA had received 95 complaints about the 3.5L EcoBoost engine in F-150 trucks misfiring. The misfires would only happen under humid or rainy conditions.
The EcoBoost engine uses twin turbochargers that compress air to increase the engine's power, and what Ford found was condensation building up inside of the air cooler tubes. When the condensation is high enough, up to three cylinders can misfire.
Ford blames EPA regulations, but finger pointing aside at least they've acknowledged the issue and that's why this is good news. It's something GM owners wish would have happened to them a decade ago.
If you have problems with your engine misfiring, definitely bring your truck in for repairs. NHTSA said they will continue to monitor complaints about the affected trucks.More information on carcomplaints.com