Spark Plug - Installation

2009 Jeep Commander 4WD V8-5.7LSECTION Spark Plug - Installation





5.7L






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. Check and adjust the spark plug gap with a gap gauging tool (1) Spark Plug Specifications.

CAUTION: Special care should be taken when installing spark plugs into the cylinder head spark plug wells. Be sure the plugs do not drop into the plug wells as electrodes can be damaged.

2. Start the spark plug into the cylinder head by hand to avoid cross threading.

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 in the spark plug gap, or a cracked porcelain insulator.

NOTE: Spark plugs have a torque critical tapered design. Do not exceed 20 Nm (15 ft. lbs.).

3. Tighten the spark plugs to 18 Nm (13 ft. lbs.).





4. To aid in coil installation, apply silicone based grease such as Mopar(R) Dielectric Grease into spark plug end of ignition coil rubber boots. Also apply this grease to the tops of spark plugs.
5. Install the ignition coil(s) (1) Ignition Coil - Installation
6. Install all necessary air filter tubing and air intake components to top of engine and to throttle body Air Cleaner Body - Installation

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.