Some 2010-2012 Ford Fusion (and 2010-2011 Mercury Milan) vehicles equipped with the 2.5L DOHC engine may exhibit an audible noise in the heater core/instrument panel area often described as a gurgle, waterfall or percolator sound. This concern typically occurs on initial engine start 1st throttle tip-in, when the ambient temperature is lower than 50 degrees Fahrenheit.
Install the Degas Service Kit using the supplied instruction sheet. The degas bottle included in the kit is from the MK2 and Fusion Sport. You should provide the correct coolant requirement label (provided).
The Degas Service Kit is available as P/N BE5Z-8522-A.