Troubleshoot Fouled Spark Plug: Regain Power & Fuel Efficiency

Spark plugs are crucial to power your engine because they ignite the spark to start the engine. A small defect or damage to these crucial components can lead to multiple troubles. You can experience lower mileage, bad car performance, difficulties in starting the engine, and rough idling as the symptoms of bad spark plugs.

Regular care and maintenance of the vehicle, especially the spark plug, is crucial to ensure the right and smooth working of the engine. It will prevent electrodes from corrosion and add to the liveability of the plugs.

Awareness of the main causes of a bad spark plug can help you to tackle this issue more effectively but most people do not have enough information about it. However, you can use our guide to explore everything about fouled spark plugs including causes, effects on car performance, and solutions.

Effect Of Bad Spark Plugs

A dirty spark plug can badly damage the car’s performance if not repaired or replaced timely. It not only reduces the car’s performance but can also result in the tearing or wearing of other engine parts which are quite expensive to replace.

Some major side effects may include;

  • Poor acceleration
  • Rough Idling
  • Engine misfire
  • Difficulties in starting the engine
  • Reduced gas mileage

Causes of Fouled Spark Plugs

Fouled spark plugs become contaminated with fuel, dust, and other harmful ingredients which lead to their destruction and reduced car performance. Therefore, immediate response to any of the above-mentioned symptoms, regular inspection, and repair of plugs are mandatory to avoid further damage.

It can damage due to multiple reasons which are listed below.

Contaminated by fuel, dust, and other harmful elements, fouled spark plugs deteriorate and diminish the performance of your car.

Oil Leak

One of the major culprits behind fouled spark plugs can be oil leaks into the combustion chamber. It results in coating the tip of the spark plug electrode and reducing its ability to ignite and start the engine.

Oil leaks into the combustion chamber can happen due to multiple reasons such as leak gasket head, damaged valves, and worn-out pistons.

Over Heating

Continuously driving the car at high rpm or using bad-quality fuel can result in overheating the engine. It causes fouled spark plugs which start burning the oil. Therefore, experiencing an unusual or burning oil smell during the drive is an indication of an oil leak or bad spark plugs.

Overheated Engines Could Be the Reason Your Car Smells Like Burning Oil

Contaminated Electrodes

Spark plug electrodes are responsible for delivering the right amount of current to produce ignition and running the engine. When they become contaminated with black soot, carbon, oil, and dust, they fail to perform their job and reduce the lifespan of car spark plugs.

Car Spark Plug
Photo: Nazly Ahmed

Improper Spark Plug Gap

Different types of vehicles have different sizes, structures, and types of spark plugs which need to be correctly gapped to ensure the normal functioning of the engine. Slight misalignment or wrong gaps can result in bad spark plugs.

Faulty Valves and Damaged Piston Rings

When we are talking or thinking about what causes spark plugs to go bad, the very first thing that comes to mind is the faulty valves and piston rings. Worn-out piston rings and loose valves can cause oil leakage to combustion.

Car Piston Ring

Damaged Head Gasket

If you are experiencing a burning oil smell and difficulties in starting the engine, your car gasket head is damaged. It is quite expensive to repair and you immediately need to send your car for professional inspection.

Head Gasket

How To Fix It?

Instant repairing of fouled spark plugs is highly crucial to retain the normal functioning of the engine. You can either perform it manually or also send your vehicle to a professional service for permanent fixing of the damaged or black spark plug issue.

You can adopt the following practices to fix this issue effectively.

Spark Plugs Cleaning

One of the best ways to fix a fouled spark plug is by cleaning or removing black smoke and white residue on it. It’s quite easy but consumes time. However, it is not a permanent solution, and your car spark plugs can any time fail to perform their function smoothly.

To address a fouled spark plug, an effective approach involves cleaning or eliminating black smoke and white residue that may have accumulated on the spark plugs.


Repairing damaged or worn-out spark plugs is also an effective solution to get rid of the effects caused by fouled spark plugs. However, regular inspection, estimating the length of damage, and fixing it again properly is crucial to fix this problem.

Replace Fouled Spark Plugs

Excessive accumulation of dust and the oil on the spark plug badly damage its functionality and the only way to retain the normal functionality of the engine is to replace the bad ones.

Bottom Line

After going through this guide, you have enough idea of what is a fouled spark plug and its causes. You can easily tackle this problem manually or call a professional mechanic for permanent relief.

Always choose a credible platform or mechanic for the regular service and cleaning of your car. It will eliminate the risk of scams and deliver exceptional results.

Last Updated on May 18, 2023 by admin

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