Various vehicles equipped with a 4.6L, 5.4L, 6.8L modular 3 valve engine built on or before 8-Jan-2016 may exhibit symptoms that may include upper end engine noise, rough running, misfire and/or engine damage. If diagnosis leads to only camshaft/camshaft roller follower(s) requiring replacement, replace all of the camshaft roller followers on both banks/cylinder heads with part number 3L3Z-6564-A, not just the faulty roller follower(s). When replacing the camshaft roller followers, refer to Workshop Manual (WSM), Section 303-01.
