The Purpose of Spark Plugs
Spark plugs take high voltage electricity from your engine’s ignition coil and create a spark at just the right moment during the engine’s combustion cycle. When this occurs, it gives the engine the best mix of power, fuel economy, and low emissions. The electrode at the end of each plug channels a lot of energy repeatedly. Eventually, this electrode wears out and your vehicle loses efficiency. When this occurs, it is time to change your spark plugs.
Spark plugs direct electricity from the ignition coil to the combustion chamber. The spark that is generated causes the air/fuel mix to ignite and creates micro explosions in the chamber itself to produce the necessary power. Without the spark the plugs produce, your engine cannot convert fuel energy into mechanical power.
Parts of the Spark Plug
- Insulator: Usually, this part is made up of ceramics, and it protects the spark plug’s firing end.
- Electrodes: This part is located on the end of the spark plug; it must tolerate extreme temperatures and corrosive conditions to generate sparks.
- Shell: This part of the plug is composed of metal, and it provides threads so that the plug can be screwed into the cylinder head.
- Gasket: This is a component that is not found on all spark plugs, but on those that do, it aids in achieving a tight seal with the cylinder head, so the plugs operate more efficiently.
How to Know If You Need New Spark Plugs
Check your owner’s manual for recommendations as to how often to change spark plugs. The interval depends on the vehicle’s maintenance schedule which is different depending on the make and model of your vehicle. Some will say every 30,000 miles, some will say every 60,000 miles, and some may even go as high as 100,000 miles. If you are not sure, here are some signs that may indicate plug replacement is necessary:
- Difficulties in starting your vehicle.
- Check engine light may be lit, and a diagnostic test may show a misfire code.
- Reduced fuel economy or a drop in power.
- Vehicle is idling roughly, or there are new or unexplained engine vibrations.
- State Emission Test failure.
It is recommended that if one plug is bad, change all of them because the bad one forces the remaining ones to channel more power. The higher workload will soon cause the others to burn out.
