The following are the key takeaways from this article:
- Internal combustion engines have sparkplugs for each cylinder.
- The function of the sparkplug is to produce a voltage spark to ignite the air-fuel mixture inside the combustion chamber.
- The sparkplugs can go faulty due to overheating, deposition of carbon, and oil in the combustion chamber.
- Faulty sparkplugs will result in trouble starting the car, idling the engine, and poor fuel economy.
- The cost to resolve sparkplug issues can range between $16-300.
Internal combustion engines combust the fuel to produce mechanical energy. When the piston compresses the fuel in the combustion chamber, the sparkplug becomes the most important part (1). The sparkplug stores voltage inside it from the distributors and ignite the air-fuel mixture for combustion.
This article will further analyze the function, common problems, and symptoms of bad sparkplugs.
The function of Sparkplugs
Sparkplugs are one of the most important parts of the engine and play a vital role in igniting a spark in the combustion chamber. The spark produced by the sparkplugs is responsible for igniting the air and fuel mixture in the combustion chamber.
To maintain the engine’s health, it is necessary to ensure the health of the sparkplugs and the electrodes.
Sparkplugs are heat exchangers that remove all the excessive heat by transferring it to the engine’s cooling system. The sparkplugs are usually made up of silver, platinum, and steel. Steel is less durable, so the mostly sparkplugs are made of steel and platinum because they have durable life (2). The sparkplugs play a vital role in accelerating the vehicle. Therefore, it is important to maintain the functioning of sparkplugs. Otherwise, the engine can face serious issues such as less power generation, engine misfires, etc.
Common Problems with the Sparkplug
Overheating of Sparkplug
Sparkplugs are important components of the engine and and their role is to ignite the fuel in the combustion chamber. Therefore if they’re damaged, they can significantly impact the engine’s overall performance and function.
The pre-ignition of the spark is one of the major reasons for producing a large amount of heat in the combustion chamber, which affects the spark plug. Also, the defective cooling system is considered a major reason for the failure of the sparkplugs, as excessive heat will accumulate in the engine (1). Thus, the electrodes of the sparkplug will get damaged when the temperature reaches above 800 °C. As a result, the sparkplug will become red, resulting in abnormal engine combustion. As a reaction, the engine’s performance will get damaged, and there are chances that there will be less acceleration in the vehicle and vibration will be produced in the engine due to poor ignition phenomenon (4).
Oil in Combustion Chamber
The dirt and debris in the oil will lead to the failure of the sparkplug. The engine oil can enter the sparkplugs due to various factors, such as damaged valve cover gaskets, broken piston guide, and defective spark O rings (2). Thus, it results in the poor performance of the engine. Due to the oily sparkplugs, there are chances that bluish-black smoke will be released from the tail pipe. This happens because the oily sparkplugs start consuming more fuel, and the fuel is not burnt properly, which results in the release of bluish-black colored smoke. This happens because the opening and closing of the valves do not occur due to the failure of the sparkplugs, and the amount of air and fuel is disturbed in the combustion chamber (3). Moreover, the fuel economy gets disturbed due to the broken sparkplug, and a slight increase in fuel consumption is observed. This excessive fuel burning will create an oxidized coating on the tip of the sparkplugs, and the powerful spark is not produced as a response.
Deposition of Carbon Sparkplugs
Also, the disturbing ratio of air and fuel in the combustion chamber results in the deposition of black soot on the electrodes. As a result, the performance of the sparkplug becomes effective. Due to this issue, there are chances of the engine misfire. Engine misfire usually occurs when there is declined combustion phenomenon. Thus, it will create troubles for the accelerator, and the electrode will produce a strong spark leading to an engine misfire. Besides, engine backfires also occur due to damage to sparkplugs. This happens when the fuel is not completely burnt and is left through exhaust valves (3). During this process, mini-explosions damage the engine’s performance.
Symptoms of a Bad Sparkplug
Following are a few symptoms of a bad sparkplug:
Trouble Starting the Car
The most common symptom of a bad sparkplug is trouble starting the car. Usually, when the car does not start, low battery is thought to be the primary reason behind it.
In this case, it is recommended to replace the sparkplugs and try starting the car (5). Of course, you can always order sparkplugs at online platforms, but do ensure the sparkplug specifications to avoid wrong orders.
Usually, an idling engine is caused by the malfunctioning crankshaft, cams, etc. In rare cases, a faulty sparkplug will also cause an idling engine (5). It is recommended to schedule an appointment with a professional when you experience an idling engine to avoid permanent engine damage.
Poor Fuel Economy
The car will need more fuel to produce the desired engine power. If a car owner is experiencing a sudden drop in fuel economy, then there is a chance that the sparkplug of a particular cylinder has gone bad (1). In this case, you must replace the sparkplugs before driving long distances.