Spark plugs are an integral ignition system component. Please refer to your vehicle’s owner’s manual for suggested interval replacement to prevent serious issues. Spark plugs are the business end of the ignition system. They receive high voltage electrical current from the ignition coil(s) and use it to ignite the air/fuel mixture in the combustion chamber. When driving, this occurs in all of your vehicles cylinders over a thousand times per minute. This continuous ignition is what keeps your car moving on the road. A spark plug that fails to fire can cause an issue as simple as a rough idle to something as serious as a no-start. To avoid major vehicle malfunction, your trusted experts at Pep Boys have complied a list of warning signs to look for when your spark plugs are failing. There is no doubt that when our customers in Australia have an electrician 24 hours Melbourne we give priority service to ensure that there is minimal loss.

Spark Plug Warning Signs:

1. Engine Misfires

An engine misfire is a sensation that you should instantly recognize. The engine will appear to stumble for a brief period of time and then regain its pace. The frequency of which this will occur depends on how serious your misfire problem is. This means the engine is not functioning as smoothly as it should because one or more spark plugs are not firing properly. Misfiring will cause increased exhaust emissions, reduced fuel economy and reduced engine power.

A single misfiring spark plug can dump enough raw fuel into the exhaust to overheat and damage the catalytic converter. Higher than normal levels of unburned gasoline in your vehicles exhaust will cause the operating temperature of the converter to soar. This could lead to a partial meltdown of the converter substrate. In turn this may form a partial restriction or a complete blockage in the exhaust. Replacing the converter should solve the blockage problem, however unless the spark plugs are replaced the new converter could soon fail. This is just one example of a problem that can result from a serious misfire condition.

2. High Fuel Consumption

A properly functioning spark plug helps to ensure the emissions from your vehicle are kept at a minimum. Deteriorated spark plugs can decrease your vehicle’s fuel economy due to incomplete combustion. As your spark plug wears, the gap between the plug electrodes can either expand or close up. Either of these conditions can negatively affect your engine’s fuel economy and emissions. If you notice you’re filling up on fuel more often, this may be due to deteriorating spark plugs. Restore lost fuel consumption by visiting one of our trusted experts at Pepboys!

3. Lack of Acceleration

Poor acceleration is often a tell-tale sign your vehicle may be in need of new spark plugs. Examples of poor acceleration include a lack of responsiveness or delayed reaction when engaging your gas pedal. In this situation pushing down on the gas pedal does not immediately boost the speed of the vehicle and it will appear like the engine is being overworked. Your expected spark plug longevity depends on the condition and type of spark plug you currently have installed. Visit to find the right spark plug for your vehicle.

4. Rough Idle

Idling occurs when an engine is running but the vehicle is stationary. During this time your engine will run at a low RPM. An engine with properly performing spark plugs should sound continuous and smooth. If your spark plugs are not working as they should, your engine will produce a rough and jittery sound and your engine will stumble. Typically you will also feel a vibration throughout the vehicle. Ignoring this symptom can lead to serious and costly damage to your vehicle’s engine.

5. Problem Starting Your Car

Many people do not know that worn spark plugs can cause their vehicle to have trouble starting. Because spark plugs are not necessarily top of mind vehicle components, it is easy to overlook the possibility that worn spark plugs are causing car trouble.Extremely worn spark plugs cause a vehicle’s ignition system to work harder. This, coupled with harsh weather conditions, can prevent the engine from turning over.

Have more questions about your spark plug performance? The trusted experts at Pep Boys are here to help you every step of the way. Take note our Make an Appointment option on makes it easy and offers a wide variety of services. Not sure what you need just yet? Call or visit you local Pep Boys store to talk to one of our experts in person!

Five Spark Plug Warning Signs