Cracked Piston Skirt
Some 2015-2017 Lincoln Navigator vehicles equipped with a 3.5L EcoBoost engine with greater than 20,000 miles may exhibit a tick type noise from the cylinder block area.
This noise may be caused by a cracked piston skirt. The noise can be isolated to a specific cylinder using a stethoscope or other suitable listening device.
Canceling the affected cylinder will reduce or eliminate the noise. If the noise is isolated to one or more cylinders, it is recommended to replace the short block.