Changing Your Spark Plugs
Spark plugs should be changed every two years, or 30,000 miles, to give you the maximum gas mileage and for the best engine performance. As with all automobile repair guidelines, some vehicles may need to be changed more (or less) frequently. Before beginning your repairs, read ALL the instructions below and gather all the materials you will need.
For this job, you will need:
1. New set of spark plugs
2. Spark plug gaping gauge
3. 3/8″ drive Spark plug socket, extension, and ratchet
4. Rag or brush
5. 12″ of 5/16″vacuum line (optional, but helpful)
You can determine the correct spark plug gap by looking for the engine specifications sticker under your hood. Always get the right spark plugs for your car, preferably the original brand. You can also consult a parts guidebook, or ask for help at the parts store- you will be there anyway to get your plugs and plug gaping gauge.
First rule to changing your spark plugs: Make sure your engine is COLD. Keep body and clothes away from the radiator fan. You can easily unplug the fan on most vehicles; you may want to do this as a safety precaution.
Grab the plug wire by the boot (base) and carefully pull the wire from the spark plug. DO NOT pull the wire itself. If it sticks, gently twist until it comes out. Changing the plugs one at a time is recommended to keep from mixing up the wires. You could also tag/number the wires.
Use the rag or small brush to clear the spark plug area of any dirt and foreign material to keep it from falling into the cylinder when the plug is removed. If you have a can/machine of compressed air, you can use it to clean the area instead.
You will then remove the spark plug by twisting it counterclockwise with the spark plug socket. Spark plug sockets have a rubber insert that will help the socket grip the plug. A typical 3/8″ socket may be used, although it will make the process a bit harder. Once you have the plug loose, spin it a few times, and then remove the plug by hand. Use the vacuum line (basically a rubber/plastic tube) to reach if necessary.
Use the gap gauge to gap your new spark plugs. You may want to gap the plugs beforehand, having them all ready once you start your repair. To correctly gap the plugs, slip the wire/feeler between the inner and outer electrodes on the tip of the spark plug. A wire gauge is better than the flat gauges. Flat gauges are often incorrect; as are some of the “pre-gapped” spark plugs available. Always make sure the gap is correct before installing the spark plugs. The wire should slide between the electrodes with just a little bit of drag once the plug is correctly gapped. You may need to gently bend the outer electrode slightly to correct the gap. The outer electrode should also be centered directly over the inner- gently align if not.
Inspect the cylinder heads (where the plugs are screwed in) for wear- they should be clean of debris and the new plugs should screw easily into the head by hand. Screw the plugs in clockwise until snug, using the vacuum line if needed. Tighten firmly with the socket. Be careful not to over tighten the plugs. A torque wrench can be used- it gauges exactly how much force is being used.
Reattach the wire to the new spark plug with a twisting motion until the boot is firmly seated on top of the plug. You should feel and hear a click as the wire and plug clamp together correctly.
Repeat these steps for the rest of the spark plugs, and your job is done!
