How To Clean A Fouled Spark Plug?

Last Updated on October 6, 2023 by Matthew Lloyd

To clean a fouled spark plug, heat a torch or butane lighter until it turns red or orange. After allowing it to cool, use a wire brush to scrub away any carbon deposits. Additionally, a small screwdriver can help scrape off remaining debris. Some individuals also find success using an oven or fire cleaner and a toothbrush to clean the spark plug thoroughly. Compressed air or blowing air can also blow off any loose debris.

Signs and Symptoms of a Fouled Spark Plug:

• Difficulty starting the engine
• Rough idling or misfiring
• Reduced fuel efficiency
• Engine hesitation or lack of power

How to Clean a Fouled Spark Plug: A Simple and Cost-Effective Solution

Step 1: Gather the Required Tools

Before we begin, gathering the necessary tools to clean the fouled spark plug effectively is essential.

1. Wrench with a hex bottom to remove the spark plug.
2. Screwdriver to assist in loosening the spark plug.
3. Torch or heat source to burn off carbon deposits.
4. Wire brush to clean the spark plug thoroughly.
5. Safety gloves to protect your hands from the heat.

Step 2: Remove the Spark Plug

To access the fouled spark plug, follow these simple steps:

1. Disconnect the spark plug cord.
2. Position the wrench with the hex bottom over the spark plug.
3. Twist the wrench counterclockwise to loosen the spark plug.
4. Once loose, continue twisting it by hand until easily removed.

Step 3: Identify and Assess the Condition of the Spark Plug

Now that you have the spark plug, it’s time to examine its condition. Look for signs of fouling, such as corrosion, carbon buildup, or a blackened end. This step helps you understand the extent of cleaning required and whether the spark plug can be salvaged.

Step 4: Heat and Clean the Spark Plug

Cleaning a fouled spark plug involves removing carbon deposits. Here’s how you can do it effectively:

1. Use a torch or heat source to heat the spark plug until it turns red or orange.
   • Be cautious not to touch the hot spark plug as it can cause burns.
   • Heat it for a few minutes until all the carbon is burned off.
2. Allow the spark plug to cool down completely for approximately ten minutes.
   • Remember, the spark plug will be extremely hot during this time, so handle it carefully.

Step 5: Thoroughly Clean the Spark Plug

Once the spark plug has cooled down, it’s time to clean off any remaining residue.

1. Take a wire brush and carefully scrub the spark plug’s electrode and insulator.
   • Ensure that you remove all the carbon buildup and other contaminants.
   • Be gentle to avoid damaging the spark plug.
2. After cleaning, use compressed air or blow into the spark plug to remove loose debris.

Step 6: Reinstall the Spark Plug

With the spark plug now clean and shiny, it’s ready to be reinstalled in your engine.

1. Insert the spark plug back into the engine socket.
2. Hand-tighten the spark plug to ensure a secure fit.
   • Be cautious not to overtighten and damage the threads.
3. Use the wrench to give the spark plug a final, gentle tightening.

Alternative Approach to Cleaning a Fouled Spark Plug

1. Identify the carbon tracks on the ceramic insulator of the spark plug. These carbon tracks appear as black lines running from the electrode to the earth.
2. To clean the fouled spark plug, use the following steps:
   • A butane torch burns off sticky deposits and carbon on the spark plug. Hold the spark plug with mole grips and heat it until the carbon burns away. Be cautious while handling the hot spark plug.
   • Once the spark plug has cooled down, take a small screwdriver and carefully scrape away the remaining carbon deposits from the top and sides of the ceramic insulator.
   • Use a fine jeweler’s file to roughen the ceramic insulator. This will create a better surface for cleaning.
   • Apply an oven or fire cleaner to the ceramic insulator, letting it frost and stick to the surface.
   • Use a toothbrush to scrub the ceramic insulator, focusing on the roughened areas. The spark plug cleaner will help break down the insulator’s carbon deposits from all sides.
   • Rinse off the spark plug with water, ensuring all cleaner residue is removed.
   • Blow out any excess moisture and dry the spark plug thoroughly.
3. After cleaning the spark plug, reinstall it into the engine and ensure it is securely tightened.
4. Start the engine and evaluate its performance. You should notice improved combustion and smoother operation.

Frequently Asked Questions (FAQs):

Key Takeaways:

• Cleaning a fouled spark plug can restore engine performance and save money.
• Method 1 involves using a torch to heat the spark plug, followed by wire brushing to remove carbon deposits.
• Method 2 involves burning off carbon deposits, scraping, filing, and using a cleaning solution to remove fouling.
• Exercise caution when handling hot spark plugs to avoid burns.
• Reinstall the cleaned spark plug and evaluate engine performance for improvements.
• Consider replacing severely damaged or unresponsive spark plugs.
• When used correctly, Acetone may provide a performance boost when added to petrol.