Ford Expedition engine issue with noise and potential spark plug or coil problem on Ford Expedition

Some Ford Expedition owners report experiencing engine issues related to spark plugs and coils, including noise and misfiring problems. A known spark plug ejection issue in the V8 engine can lead to spark plugs being ejected from the cylinder head due to short and soft threads, resulting in tapping or knocking noises, misfires at all speeds, and the illumination of the check engine light. Additionally, driving with bad spark plugs can cause engine damage or harm to the catalytic converter, necessitating urgent repairs to avoid costly consequences. If spark plugs are ejected, owners may need to fix the spark plug port threads or replace the cylinder head and gasket. Ford has issued a technical service bulletin for this issue affecting model years 1997 through 2007, with replacement costs ranging from $390 to $467. Furthermore, the 5.4L engine is prone to ignition coil failures, which can also lead to misfires and other significant problems. It is advisable for owners experiencing these issues to have their spark plugs, coils, and related components inspected and serviced by a qualified mechanic to prevent further damage and ensure optimal performance.