LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2009 >> Commander Overland, 4WD >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Ignition Control (Service Information) >> Spark Plug >> Installation >> 4.7L
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Spark Plug: Installation: 4.7L

Fig 1: Identifying Ignition Coil - 3.7L/4.7L
GC0082812Courtesy of CHRYSLER LLC
CAUTION: This engine uses TWO DIFFERENT types of spark plugs. A total of 16 plugs are used. The plugs are mounted in two rows (banks). The upper row (5) is used on the intake valve side of the cylinder head. The lower row (6) is used on the exhaust valve side of the cylinder head. The upper row (5) uses Bosch Nickel Yttrium plugs. The lower row (6) uses Bosch Iridium plugs. DO NOT INTERCHANGE THESE PLUGS.
CAUTION: Never use a motorized wire wheel brush to clean spark plugs. Metallic deposits will remain on spark plug insulator and will cause plug misfire.
CAUTION: Do not attempt to clean any of the spark plugs. Replace only.
  1. To aid in coil installation, apply silicone based grease such as Mopar® Dielectric Grease into spark plug end of rubber boots (4) and (7). Also apply this grease to the tops of spark plugs (5) and (6).
    Fig 2: Setting Spark Plug Gap - Typical
    GC0082815Courtesy of CHRYSLER LLC
  2. NOTE: Two different spark plug gaps are used.
  3. Check and adjust spark plug gap(s) with a plug gap gauging tool (1). See Specifications  .
  4. NOTE: Do not drop spark plugs into the plug wells as electrode damage can occur.
    NOTE: Always tighten spark plugs to the specified torque. Certain engines use torque sensitive spark plugs. Over tightening can cause distortion resulting in a change to the spark plug gap, or a cracked porcelain insulator.
    CAUTION: Due to tight clearances between upper row of plugs (5) and cylinder head, a conventional deep, thick-wall spark plug socket will not fit. Use a deep, THIN-WALL 5/8" spark plug socket for plug removal and installation.
  5. Using special care install spark plug(s) into the cylinder head by hand to avoid cross threading.
  6. Tighten spark plug(s) to the specified torque. See Specifications  .
  7. Install ignition coil(s). See Installation  .
  8. Install necessary air filter tubing and air intake components to top of engine and to throttle body.