Lincoln Navigator: Engine Ignition - 3.5L EcoBoost (272kW/370PS) / Spark Plugs. Removal and Installation

Removal

1. Remove the ignition coil-on-plugs.
   Refer to: Ignition Coil-On-Plug (303-07 Engine Ignition - 3.5L EcoBoost (272kW/370PS), Removal and Installation).
   

1. Use compressed air to remove any foreign material in the spark plug well before removing the spark plugs.
   

1. NOTICE: Do not remove the spark plugs when the engine is hot or cold soaked. Spark plug thread or cylinder head damage can occur. Make sure that the engine is warm (hand touch after cooling down) prior to spark plug removal.

   NOTICE: If a spark plug is dropped, internal damage may result and the spark plug must be discarded. The use of a damaged spark plug may cause cylinder misfire resulting in engine damage.

   Remove the spark plugs.
   

1. Inspect the spark plugs.
   Refer to: Spark Plug Inspection (303-00 Engine System - General Information, General Procedures).
   

Installation

1. NOTICE: If a spark plug is dropped, internal damage may result and the spark plug must be discarded. The use of a damaged spark plug may cause cylinder misfire resulting in engine damage.

   Install and tighten the spark plugs.
   Torque: 133 lb.in (15 Nm)

1. Install the ignition coil-on-plugs.
   Refer to: Ignition Coil-On-Plug (303-07 Engine Ignition - 3.5L EcoBoost (272kW/370PS), Removal and Installation).