Liberty KJ Spark Plug Specifications

Spark plugs for your KJ Liberty will need to be replaced regularly, but it is important that you use only the make and type recommended for the vehicle.

Spark plugs for your KJ Liberty will need to be replaced regularly, but it is important that you use only the make and type recommended for the vehicle. Because of the function spark plugs provide, purchasing the wrong spark plug can make the difference in your Jeep’s ability to provide all of the power to the drivetrain. The recommended spark plugs for the Liberty KJ utilize copper as one of the key components. These will be wrapped and protected by a ceramic covering. Spark plug wires attach the plugs to the engine and allow for the transfer of the spark. Selecting the wrong spark plugs can interrupt this important function, or limit its working capacity. The following chart has been provided so you can make certain to use either the NGK or the Champion copper spark plugs in the sizes that are recommended for your year KJ.

DescriptionTypeGap3.7LNGK® or Champion® Copper Spark Plug0.042 in / 1.1 mm2.4LNGK® or Champion® Copper Spark Plug0.048 to 0.053 in / 1.24 to 1.37 mm*Notes*Nominal refill capacities are shown. A variation may be observed from vehicle to vehicle due to manufacturing tolerance and refill procedure.** Gelling will occur if mixing different antifreeze formulas. Complete cooling system flush must be performed to evacuate all remaining old antifreeze before adding different antifreeze formula***If vehicle previously equipped with (green) 3 Year Antifreeze, recommended replacing with (pink/orange) 5 year 100,000 mile formula, only after evacuating all previous antifreeze**** All ZJ Grand Cherokee's originally required ATF+3 Automatic Transmission Fluid.ATF+4 supercedes all prior ATF formulas as ATF+4 has improved cold viscosity, anti-shudder properties, and longer friction coefficient wear***** DOT 4 Brake fluid may be used if DOT 3 cannot be found. DOT 4 brake fluid has shorter service life****** NEVER use R-12 refrigerant in ZJ Grand Cherokee A/C system******* Never use Ethanol based fuels in ZJ Grand Cherokee fuel system, IE: E-85, E-90. Fuel system components cannot support ethanol based fuels