Step-by-step instructions for removing and replacing spark plugs.
In order to operate an internal combustion engine, three central elements are needed: fuel, air, and spark – also known as ignition. That ignition is provided by components known as spark plugs.
Spark plugs leverage a vehicle’s high-voltage system in order to create an electrical arc across a ‘plug gap,’ which is located at the bottom of each component. In turn, the spark event excites fuel/air vapors in the engine’s combustion chamber, thereby initiating its power cycle.
To better understand the role these parts play in your vehicle’s operation, let’s unpack why spark plugs are important and how you can keep them in tip-top shape from the convenience of your home garage.
Spark Plugs 101
As suggested, plugs represent the central ignition point for the engine. Unsurprisingly, regular plug maintenance is critical to both reliability and optimizing performance.
Combustion Efficiency.
Properly functioning plugs ensure consistent spark. This in turn, leads to efficient fuel combustion which delivers optimal fuel economy, reduces emissions, and improves engine performance.
Heat Dissipation.
Plugs are exposed to extremely high temperatures caused by the combustion process. Materials used in plug construction dissipate heat, thereby marginalizing the potential of overheating.
Optimize Performance.
As a general matter, plug maintenance optimizes overall engine performance.
Start Efficiency.
Plugs are critical to the engine start cycle. Efficient ignition drives an engine’s fuel/air mixture – which means that badly maintained plugs will make engine starts more difficult and exacerbate wear and tear.
Maximize Horsepower.
Plug electrode designs affect the combustion process with the goal of ensuring that an engine’s fuel burn is optimized, thereby creating maximized power.
Periodic plug replacement is necessary for several reasons, but the main three are: general wear and tear, plug “fouling,” and heat mitigation.
As noted, spark plugs are subjected to high temperatures and pressure when operating. Over time, the electrodes, insulator, and other components break down. This results in reduced performance and difficulty during engine starts.
Additionally, over time, plugs can accumulate carbon deposits, oil, and other particulates called “fouling.” This condition can occur when oil escapes the engine block or runs rich. Fouled plugs exhibit marginalized spark leading to misfires, reduced power, and poor fuel economy.
Plug heat ranges are determined by their design and materials. If a heat range is non-compliant with a particular engine’s operating requirements, the condition can lead to overheating or fouling.