How to Change Spark Plugs
Bad plugs can cause you all kinds of engine problems, so it is a good idea to learn how tochange spark plugs. Worn out plugs can lead to hard starts, reduced engine power, misfires and increased fuel consumption. After thousands of driving miles, the ignition process in the combustion chamber begins to coat the plug tip with ash, oil and other byproducts. This has a burning and wearing effect on the electrodes, widening the gap between them and creating a bigger demand for voltage from the ignition system. However, by investing a few minutes of your time and installing a new set ofspark plugs, you can fix many of these problems and restore engine performance.1. Removing old spark plugsFirst, remove the spark plug wire. Start at one of end of the engine, working your way towards the other end. Grab the wire by the boot-the rubber cap placed over the spark plug. If it is hard to reach or you don’t have complete access to the boot, use spark plug wire pliers. Twist the boot back and forth, as you pull the wire off the plug. Vehicle models withdirect-ignition systemsdon't use spark plug wires. Instead, they use coils over the spark plugs. In this case, you can just unscrew the bolt(s) holding the coil in place and pull the coil off the spark plug.Remove all the dirt and debris accumulated around the spark plug well in the engine’s cylinder head. This will prevent foreign particles from going into the chamber when you remove the plug. They can scratch the cylinder walls during engine operation, lead to oil leaks and expensive repairs. One way to clean around the spark plug is to use a bicycle air pump. When ready, remove the plug using a spark plug socket, ratchet extension and ratchet. Unscrew the spark plug and remove it from the engine.Compare the old spark plug to the new one and make sure it has the same configuration. Your car owner’s manual will tell you the correctgap calibrationfor the new spark plug. Some vehicles come equipped with a Tune-up sticker located around the engine compartment. This label provides different specifications to guide you when performing engine maintenance work on your car, including spark plug gap. To set the gap for your new plugs, use a wire feeler gauge.2. Installing new spark plugsPlace the new spark plug in the spark plug socket, so the rubber grommet inside the socket holds the plug in place. Install the extension on the socket and start the new spark plug by hand on the cylinder head. This will prevent you from damaging the plug or engine threads. Tighten the spark plug using a torque wrench or the procedure specified in your vehicle service manual. If you don’t have this manual on hand, you can consult one in your local public library.Now you can reinstall the plug wire over the new spark plug. Push the wire boot over the plug until you hear or feel the metal clip in the boot snap over the plug fitting. To replace the next spark plug, follow the above procedure until you have installed the last plug. Replacing one spark plug at a time reduces the risk of mixing spark plug wires, which will lead to engine performance problems.One final point. Your car owner's manual or the service manual for your specific vehicle make and model will recommend the best spark plugs for your car. Learning how to buy and how to change spark plugs will extend the service life of your engine and save you hundreds of dollars in engine maintenance every year.
