How Often Should I Have My Spark Plugs Replaced?

The engine of a vehicle works as a system. When parts in the vehicle’s engine go bad, the engine will experience a variety of problems and can potentially damage itself as well. Spark plugs are one of the important components of your vehicle’s engine. Your vehicle’s engine relies on its spark plugs to function correctly so that it can run properly. When the spark plugs in your vehicle’s engine are beginning to fail, your vehicle will have several problems and will eventually refuse to start when the spark plugs have failed. To avoid experiencing frustrating problems, you should routinely replace the spark plugs that are in your vehicle’s engine.


Spark Plug Maintenance 

Manufacturers typically recommend that drivers change the spark plugs of their vehicles every 30,000 miles. Most vehicles, depending on their engine designs, have one spark plug for each of the engine’s cylinders. Some vehicles have two spark plugs for each of their engine’s cylinders. Refer to the owner’s manual of your vehicle if you would like to know more about the maintenance routine that your vehicle’s manufacturer recommends for the model.

The Role of Spark Plugs 

Spark plugs are necessary for your vehicle’s engine to produce power. Every cylinder in your vehicle’s engine has a mixture of both air and fuel that is injected into the cylinder as the vehicle is running. When the air and fuel are compressed, the spark plugs of the cylinders provide sparks that ignite the mixtures, which in turn force the pistons within the engine’s cylinder to move down. As the pistons move down, they allow the crankshaft of your vehicle’s engine to turn.


Signs of Bad Spark Plugs

An engine will provide several warning signs when its spark plugs are worn out and need to be replaced. Initially, an engine may begin to use more fuel as it runs. The engine will use more fuel to compensate for the lack of spark that it is receiving for its air-fuel mixtures.


When the spark plugs of an engine are getting worn out, an engine may also begin to misfire or make knocking and rattling sounds. Misfiring and these rattling sounds are caused by the spark plugs of the engine firing at the wrong times or not firing at all. Over time, this can damage an engine severely.


The engine of a vehicle will produce a noticeable drop in performance when its spark plugs are worn. As a driver presses on the accelerator pedal of their vehicle, they will notice that the engine does not want to provide power for the vehicle. Due to the direct effect that spark plugs have on the power that an engine produces, the engine’s power will not be optimal when its spark plugs are worn.


When the spark plugs of a vehicle are close to failure, they may not allow the vehicle’s engine to start at all. The sparks of a spark plug get weaker as the spark plug ages. Therefore, over time, the spark plug may not even ignite when the vehicle’s engine is turned on.


How Spark Plugs Fail

Spark plugs can fail in several ways. One of the most common ways that an engine’s spark plugs may fail is by refusing to produce sparks. Spark plugs have gaps at the ends of their plugs. Arcs of electricity, the plug’s sparks, are sent across the gaps when the spark plug is operational. Over time, as the spark plugs go through more cycles, the gaps of the spark plugs get larger. When the gaps of the spark plugs are too large, the plugs cannot produce electricity.


Spark plugs can fail by being clogged with fuel. When spark plugs don’t fire, or fail to fire at the proper times, excess fuel is left as deposits on the plugs. These fuel deposits eventually build up on the spark plugs and clog them, preventing them from producing electricity between their gaps.


Benefits of Changing Your Vehicle’s Spark Plugs

You will experience several benefits after you change the spark plugs that are in your vehicle’s engine. Initially, if the spark plugs in your vehicle’s engine were worn, you will notice that your vehicle is running smoother. You may also notice that your vehicle is providing better fuel economy, requiring you to visit the gas station less often. You may also notice a slight boost in the performance of your vehicle, with the vehicle providing better acceleration and quicker starts.



The spark plugs in your vehicle’s engine have vital roles in the engine as it runs. Without properly functioning spark plugs, your vehicle may not run. Spark plugs, however, are only used in gasoline engines. At Herrin-Gear Chevrolet we can help you maintain your vehicle and keep the vehicle running in great condition. We offer a variety of products and services at our dealership and will provide what you need for your vehicle. Visit us today so that we can assist you.