This engine 3.7 AND 4.0 has an individual ignition coil for each cylinder. When you open the hood you will see the six coils that go down into the heads, just inboard of the valve covers. The coils have one 10mm nut that hold them in, and they each have a two wire electrical connector. You'll unplug the electrical connector, remove the 10mm nut and then pull the coil out.
Once it's out then you'll need a spark plug socket and at least a 6" extension to be able to reach the spark plugs down in their recesses. They are standard 5/8" hex spark plugs.
The gap should be set at .043" and you'll want to replace them with NGK ZFR6F-11G plugs.
Spark Plugs Spark plugs must fire properly to assure engine performance and emission control. New plugs should be installed at the mileage specified in the appropriate maintenancechart.Theentiresetshouldbereplacedifthereis any malfunction due to a faulty spark plug. Refertothe“VehicleEmissionControlInformation”label in the engine compartment for spark plug information.
Each individual spark plug is located under each ignition coil. Each individual ignition coil must be removed to gain access to each spark plug. See REMOVAL.
1. Remove necessary air filter tubing at throttle body. 2. Prior to removing ignition coil, spray compressed air around coil base at cylinder head. 3. Prior to removing spark plug, spray compressed air into cylinder head opening. This will help prevent foreign material from entering combustion chamber. 4. Remove spark plug from cylinder head using a quality socket with a rubber or foam insert. Also check condition of ignition coil O-ring and replace as necessary. 5. Inspect spark plug condition.
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. Over tightening can cause distortion resulting in a change in the spark plug gap or a cracked porcelain insulator.
1. Start the spark plug into the cylinder head by hand to avoid cross threading. 2. Tighten spark plugs. Refer to Spark Plug Torque Specifications. 3. Before installing ignition coil(s), check condition of coil O-ring and replace as necessary. To aid in coil installation, apply silicone to coil O-ring. 4. Install ignition coil(s).
Mar 10, 2018
This video provides tips on removing the spark plug coil packs on a 2010 Dodge Nitro 3.7L vehicle. Since the 2010 Jeep Liberty is essentially the same vehicle it may be useful for that one as well.
Jun 8, 2019
Hello Everyone! If you're about to replace or are thinking about replacing the spark plugs on your dodge nitro 3.7 then this is the video for you!
I've also included a tip on how to remove the ignition coil easily