TSB 23-2143

Some 2017-2020 F-150 and 2018-2020 Expedition/Navigator vehicles built on or before 30-Nov-2019 and equipped with a 3.5L EcoBoost engine may exhibit a ticking/tapping or rattle type noise from the top front cover area of the engine on initial start-up after a cold soak of 6 hours or more that may last for 2-5 seconds. Some vehicles may also exhibit an intermittent condition with no auto restart during auto-start-stop operation with or without diagnostic trouble code (DTC) P164C present in the powertrain control module (PCM). This may be due to a worn variable camshaft timing (VCT) unit. To correct the condition, follow the Service Procedure to replace the VCT units.