Some known issues with the Ford 5.4-liter, three-valve V-8 engine include problems with the engine's cam phasers that can lead to camshaft failure in high-mileage engines and durability issues with the engine's head gaskets. Engines beginning to experience problems related to these issues may tick when they first start up or lose power while running, and they may also cause the check engine light of the car or truck to illuminate.
The camshaft phaser in the Ford three-valve 5.4-liter engine is responsible for controlling the valve timing of the engine's valvetrain by regulating the motion of the camshafts of each cylinder bank in the engine and insuring that they operate the valves for each bank in unison. If the camshaft phaser is defective or damaged, incorrect operation of the engine valves may retard the engine's performance. In the long term, a malfunctioning camshaft phaser can lead to failure of the engine's camshafts, and it may also cause problems with the engine's timing chain system that can increase the chance of its failure.
Ford's older two-valve 5.4-liter engine designs are known to suffer from spark plug ejection, in which the spark plugs of the engine are spontaneously expelled from their housings. Ejections may strip the spark plug hole threads and damage the engine's cylinder heads. Ejections may also result in a potential engine fire if gasoline vapor exits the engine through the spark plug hole and ignites.