What are the Symptoms of Bad or Failing Spark Plugs?

January 27, 2022

Four silver spark plugs, against a blue background. | Rocky Mountain Car Care

Spark plugs play a vital role in the internal combustion process, which produces power for your engine. Spark plugs ignite the combustion chamber where the fuel-air mix. Spark plugs require routine service and replacement just as the fuel filters and air filters.


To achieve optimum performance, your spark plugs should be clean and there should not be any damage to the electrodes.


What is a Bad or Fouled Spark Plug?

Dirty or fouled spark plugs can affect the running of the engine. A bad or fouled spark plug is one that is covered with fuel, oil, and carbon. It could also be blistered because of running too hot.


Driving with bad or fouled spark plugs may cause multiple problems to your engine.


Symptoms of a Bad or Failing Spark Plugs

Below are some of the common signs and symptoms of bad or failing spark plugs:


Engine Misfire

Faulty spark plugs result in an engine misfire due to incomplete burning fuel. An interrupted combustion process can significantly affect the engine performance.


Unattended engine misfire may result in intermittent strange engine sounds, power loss, and engine knock.


Rough Idling

The engine sounds smooth and steady when your spark plugs are in good condition. However, faulty spark plugs can make your engine sound too rough when idling. In fact, you may also feel your car vibrating.


Hard Starts

When having trouble starting your vehicle, your first guess would be an empty gas tank or dead battery. Do not rule out the possibility of faulty spark plugs. Your car will not start if your spark plugs cannot produce the spark to initiate the process of internal combustion.


Poor fuel Economy

Bad or fouled spark plugs will result in a significant increase in fuel consumption. You may notice up to 30 percent fuel consumption increase.


Loss of Acceleration Power

Faulty spark plugs can also make your vehicle lose its get-up-and-go. When your vehicle loses acceleration power, you are also likely to use more fuel.


Getting Started

Even though most problems due to faulty spark plugs are relatively easy to fix, continuing to drive with bad or fouled spark plugs may result in serious problems that are costly to fix. If you experience any of the symptoms above or suspect any engine problems, we invite you to bring your vehicle into Rocky Mountain Car Care today.


See our other services here.


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