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 cylinder using a stethoscope or other suitable listening device. Cancelling the affected cylinder will reduce or eliminate the noise. If the noise is isolated to a specific cylinder, it is recommended to replace the short block.