Tools and materials needed:
- Spark plug wrench
- 5/8-inch socket
- Extension bar
- Ratchet
- New spark plugs (4)
1. Prepare the vehicle: Park the vehicle on a level surface, apply the parking brake, and turn off the engine. Allow it to cool down if the engine has been running recently.
2. Remove the engine cover: Locate the engine cover, which is usually a black plastic cover on top of the engine. There may be some plastic clips or bolts holding it in place. Remove these to access the engine compartment.
3. Locate the spark plugs: On the 4.2L engine, the rear spark plugs are located on the back of the engine, closest to the firewall. There will be two spark plugs on each side of the engine.
4. Disconnect the ignition coil connectors: Each spark plug has an ignition coil connected to it. These are usually black with a wiring harness attached. Use the spark plug wrench to twist and remove the ignition coil connectors from the spark plugs.
5. Remove the old spark plugs: Use the spark plug wrench with the extension bar and ratchet to remove the old spark plugs. Turn counterclockwise to loosen and remove them.
6. Install the new spark plugs: Take one of the new spark plugs and screw it into the cylinder head by hand until it is snug. Use the spark plug wrench to tighten the plug until it seats firmly but do not overtighten. Repeat this process for the remaining three spark plugs.
7. Reattach the ignition coil connectors: Once the spark plugs are installed, reattach the ignition coil connectors by pushing them back onto the spark plugs until they click.
8. Replace the engine cover: Once all four spark plugs are replaced and the ignition coil connectors are reconnected, replace the engine cover. Make sure it is securely fastened.
9. Start the engine: Turn the key to start the vehicle and let it run for a few minutes to check for any issues or leaks.
Note: It is important to use the specified spark plugs for your vehicle's engine. Refer to your owner's manual or a reliable parts store to ensure you have the correct spark plugs. Additionally, if you are not comfortable performing these steps yourself, it is recommended to have the spark plugs changed by a professional mechanic.
