Spark Plugs: Installation

WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: The 4.7L is equipped with copper core ground electrode spark plugs. They must be replaced with the same type/number spark plug as the original. If another spark plug is substituted, pre-ignition will result.

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. Always tighten spark plugs to the specified torque. Overtightening can cause distortion resulting in a change in the spark plug gap or a cracked porcelain insulator. On 3.9L and 5.9L, when replacing the spark plug and ignition coil cables, route the cables correctly and secure them in the appropriate retainers. Failure to route the cables properly can cause the radio to reproduce ignition noise. It could cause cross-ignition of the spark plugs or short circuit the cables to ground.

Start the spark plug into the cylinder head by hand to avoid cross-threading. Tighten spark plugs to specification. See TORQUE SPECIFICATIONS .
On 3.9L and 5.9L, install spark plug cables over spark plugs. Install cables into the proper engine cylinder firing order. When installing new cables, make sure a positive connection is made. A snap should be felt when a good connection is made between the plug cable and the distributor cap tower.
On 4.7L, before installing coil(s), check condition of coil "O" ring and replace as necessary. To aid in coil installation, apply silicone to coil "O" ring. Install ignition coil(s).