What do the spark plugs do?

Spark plugs are vital components in internal combustion engines. Their primary function is to ignite the air-fuel mixture within each combustion chamber. When an electrical signal is sent from the ignition system, the spark plug generates a high-voltage spark across the electrode gap. This spark ignites the compressed air-fuel mixture, initiating the combustion process.

Spark plugs also play a role in heat dissipation. They have a ceramic insulator that helps transfer heat from the combustion chamber to the engine cooling system, preventing overheating and maintaining optimal operating conditions. The threaded metal shell of the spark plug acts as a seal, preventing combustion gases from leaking out and maintaining proper compression in the cylinder.

Additionally, spark plugs feature a self-cleaning mechanism. As they operate, carbon deposits and contaminants can accumulate on the electrodes, affecting performance. However, the high-voltage sparks generated during each firing burn off these deposits, keeping the electrodes clean and ensuring consistent spark performance.


When should the spark plugs be replaced?

Although they are built to be very durable, the spark plugs are subject to high levels of heat and pressure. This can lead to them eventually wearing and needing replacement. Many modern cars come equipped with extended-life iridium spark plugs, which can last over 100,000 km before failing. However, it should be noted that engine performance will be affected long before the spark plugs fail entirely. For this reason, it pays to judge the health of your spark plugs by the presence of symptoms, rather than kilometers traveled.

As for standard copper spark plugs, most mechanics will recommend having them replaced every 10,000 to 20,000 km.

Learn more about the different types of spark plugs

Additionally, certain driving conditions and factors can accelerate spark plug wear and necessitate more frequent replacement. These conditions include:

  • Severe driving conditions: If you frequently drive in extreme temperatures, heavy traffic, dusty environments, or engage in towing or hauling, it can put additional stress on the spark plugs. In such cases, more frequent spark plug replacement may be necessary.
  • Performance modifications: If your vehicle has undergone performance modifications, such as an aftermarket turbocharger or supercharger installation, the increased power output can put greater demands on the spark plugs. Upgraded or more frequent spark plug replacement may be required to accommodate the higher performance levels.


Symptoms of worn spark plugs:

  • Increased misfires – Misfires occur when your car’s engine misses a step in its combustion cycle and fuel is not burnt correctly. Faulty spark plugs may not produce a spark that is powerful enough to properly ignite the fuel. This can lead to fuel not burning and causing misfires.
  • Rough idle – If the spark plugs are worn, the engine may exhibit a rough or uneven idle. You may notice the engine shaking or vibrating more than usual when the vehicle is at a stop.
  • Increased fuel consumption – If your car is using more fuel than normal, it could be due to a worn spark plug. Bad spark plugs cause fuel to not burn correctly, resulting in it going to waste.
  • Loss of power / slow acceleration – If your car is not accelerating as quickly as normal, a spark plug could be the cause of the problem. When spark plugs cannot provide the necessary spark to power the engine, performance will suffer as a result.
  • Difficulty starting your car – Spark plug failure can lead to your car struggling to start or not starting at all. A broken spark plug will produce no spark, resulting in no combustion occurring in the engine.

Car not starting – Repairs in Hamiton


Spark Plug Replacement Service in Hamilton

Is your car in need of new spark plugs? If so, we can help!

At Grimmer Motors, our experienced team of mechanics can examine, repair and replace your car’s spark plugs. This will allow for improved engine performance at all times as well as greater fuel economy. For spark plug replacement in Hamilton, contact Grimmer Motors today!


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