Some 2007-2008 Mercury Mountaineer vehicles equipped with a 5.4L engine may exhibit a Front End Accessory Drive (FEAD)-related high pitch metallic whistle/hoot noise after a cold soak in ambient temperatures below 40 degrees Fahrenheit.
This noise may be caused by the grooved nylon FEAD idler pulley.
Replace the nylon idler pulley with P/N 6L3Z-6C348-A.
PreviousFord Diesel EGT
NextThe Pin Took a Walk