Bad Spark Plugs: Common Symptoms and How To Detect It


Your engine’s spark plugs should be clean and free of damage to the electrodes for optimal performance. Your engine’s performance may be affected if your spark plugs become filthy or fouled. A dead spark plug symptoms are one that has become become covered in a substance such as oil, petrol, or carbon, or one that has blistered due to excessive heat. Driving with clogged or damaged spark plugs might result in a slew of issues for your engine.

What Do Spark Plugs Do?

Your spark plugs are responsible for delivering the spark that ignites the air/fuel mixture, resulting in an explosion that causes your engine to produce power. These small but straightforward plugs generate an arc of electricity across two leads that are not touching but are close enough together that electricity can jump the gap between them. Your ignition system includes your spark plugs as well as the electrical and timing equipment that powers them.

Bad Spark Plugs

Your spark plugs are generally made of extremely durable material that can withstand millions and millions of explosions before wearing out or needing to be replaced. However, it is true that over time, explosions and corrosion cause smaller or weaker sparks, which reduces engine efficiency and may cause other issues such as misfiring.

Signs and Symptoms of Faulty Spark Plug

Symptoms of Faulty Spark Plug

Reduced Gas Mileage

Visiting the petrol station more frequently? Spark plugs that are filthy or clogged might cause a dramatic decline in fuel economy.  It is the most generic dirty spark plug symptoms. If your spark plugs aren’t working properly, your gas mileage will suffer.

Lack of Acceleration

Bad spark plugs could be to blame if your vehicle has lost its oomph. When a spark plug becomes clogged or unclean, it loses its ability to ignite effectively, causing your automobile to run slowly.

Hard Starts

Are you having difficulties starting your car? While your initial instinct could be a dead battery or an empty petrol tank, it’s possible that defective spark plugs are to blame. You won’t be able to start the combustion process if your spark plugs can’t produce a spark.

Engine Misfires

Another spark plug faulty symptom is the misfiring of the engine. Faulty spark plugs can cause an engine to hesitate or misfire instead of running smoothly. If the combustion process is halted, even for a brief while, your engine’s performance will decrease.

Rough Idling

Your engine will sound smooth and steady when your spark plugs are working properly. Your engine will sound harsh when idling if it has a fouled spark plug. You may also notice that the vehicle is trembling.

If your car is exhibiting any of these symptoms, it’s time to visit your trusted technician. The majority of problems caused by a defective spark plug are simple to repair. Continuing to drive with fouled or dirty spark plugs, on the other hand, might lead to more significant and costly problems.

Is it Bad to Drive with Bad Spark Plugs?

Having symptoms of bad spark plugs in a car have negative consequences.  The engine oil will become contaminated by unburned gasoline and eventually increase engine wear over time.

The amount of unburned fuel will be too much for the catalytic converter. It will become substantially overworked as a result and collapse within. The car will emit a lot of pollution. These elements are what cause the check engine light to flare at you, such as one caused by a malfunctioning spark plug.

When Should you Replace your Spark Plugs?

Spark plugs will last for many years and miles before needing to be replaced. However, automakers recommend replacing them every 30,000 miles.

The life of a spark plug is determined by the type of plug. When compared to platinum or iridium, copper spark plugs have a shorter life.

Replace spark plugs with the original manufacturer’s choice. If the same spark plug is not there, replace it with high-quality spark plugs. Copper plugs are inferior and will corrode quickly.


What happens if you have faulty spark plugs while driving?

Engine issues brought on by malfunctioning spark plugs include misfires, difficult starts, poor gas mileage, rough idling, and a lack of acceleration.

Can faulty spark plugs make noise?

Inefficiently working spark plugs result in an uneven fuel burn in the engine, causing the RPMs to fluctuate and the noise to get louder. Additionally, your vehicle may vibrate more intensely while idling or moving at a slow speed. The entire car may shake as a result of these vibrations.

Can faulty spark plugs trigger a code?

Your engine may misfire due to faulty spark plugs. These misfires are discovered by sensors used by the engine’s computer, which then generates a code that lights up the check engine light.

Can defective spark plugs slow down acceleration?

Because of incomplete combustion, malfunctioning spark plugs can increase fuel consumption and pollutants. A car’s ineffective acceleration is another indication of bad spark plugs. As a result, when the accelerator pedal is depressed, the engine struggles to respond and build speed.

Leave a Reply

Your email address will not be published. Required fields are marked *

Request a Quote For

Sirdebar Contact Us

Request a Callback

Contact Us

This will close in 0 seconds

Your Request Has Been Submitted
The Next Step is To Contact US

+1 (252)-503-4920

This will close in 20 seconds

Need Help?