How To Clean Spark Plugs

Spark plugs are essential to the running of the engine, so it is important to keep them clean. Cleaning spark plugs is a quick and easy way to keep them working, but it’s important to consider why they need to be cleaned. Replacing old, dirty spark plugs is usually best, but cleaning them will keep your car running until you can find a replacement. You can effectively clean spark plugs with abrasives like sandpaper or a file, but if you don’t have either, a blowtorch will do just fine.

In this article, we will discuss in detail how to clean spark plugs using spray guns, abrasives, and spark plug cleaning tools.

How To Clean Spark Plugs

Cleaning spark plugs is a mechanical task that every entry-level mechanic and DIYer can perform effectively. In any case, there are various ways to clean sparks.

When planning to clean the spark plug, you need to remove it; First, there’s nothing better than cleaning spark plugs without removing them. Before selecting the method to use, you need to access the plug by removing it.

Step 1: Removing Spark Plugs

Locate the spark plug by tracing the ignition coil or spark plug lead. If you find it difficult to locate spark plugs in your car, refer to the user’s manual

Once the spark plug is found, clean the area around the dirt and debris to prevent them from falling into the plug hole when removing the spark plug. Ideally, I recommend using compressed air to blow away dirt and debris.

If dust or debris falls into the spark plug hole while removing the spark plug, catastrophic damage can occur. Be sure to wear goggles when blowing garbage away with canned or compressed air.

Remove one socket wire at a time. This will help you place the spark plug lead correctly to avoid engine stall/backfire and reduce the risk of things falling into the plug hole when you unscrew the spark plug.

Removing all plug cords at the same time will not confuse you when you reinstall. When removing the high voltage cable, secure it firmly to the low sheath and then pull it out gently. If any cables are difficult to pull out, hold firmly and loosen slightly.

Take a spark plug socket and connect it to the extension and ratchet handle. Place the plug socket into the spark plug hole and turn counterclockwise to loosen and unscrew the plug. When it is free, remove the handle and loosen it by hand.

Most spark plug holes have rubber seals that clamp the spark plug to prevent it from falling out when removed from the hole. When removing spark plugs, watch out for debris and blow it away so it does not fall into the cylinder head.

Step 2: Clean the Spark Plug

Method 1: Cleaning With Abrasive

Clean the electrodes with 220 grit sandpaper: There is always a small electrode sticking out of the end of the spark plug (the part that goes into the engine). It’s called an electrode. If it has carbon buildup or discoloration, take a piece of sandpaper and gently clean it until there is no carbon on it.

Continue to sandpaper the electrode until it looks like bare metal. It is recommended to wear goggles when sanding. Sandpaper is one of the best spark plug cleaners on the market.

Clean up deposits with a file: Sandpaper should do the job, but if not, consider filling stubborn deposits with a file. Place the file on the gap between the plug body and the electrode and slide it back and forth.

Clean thread with a wire brush: There may be dirt and oil on the thread of the plug. If there is oil on it, it means there is oil in the spark plug hole. Clean the spark plug hole before reinstalling the spark plug. Brush the plug from a vertical Angle to easily remove sediment and debris from the thread. Then, turn and brush the plug at different angles.

When cleaning plugs with a wire brush, make sure you wear gloves to avoid stabbing yourself. Threads do not need to maintain their color to work, but need to remove all sediment.

Use CarB Cleaner: CarB cleaners are available at nearby auto stores and online stores like Walmart, eBay, and Amazon.

If you’re an entry-level mechanic, you might be wondering how to clean spark plugs with a car cleaner. Carb cleaners are designed to effectively clean carbon, scale, dirt, and garbage from multiple auto parts.

To use CARB cleaner for cleaning, place the spark plug on a clean vice-like surface and spray the cleaner over it. After spraying, wipe with a clean towel. In addition to cleaning, it will dry out quickly, leaving a clean spark plug.

If carbon buildup is difficult to clean, use a wire brush and CARB cleaner. When finished, wipe the plug thoroughly with a clean towel or cloth and dry the carb cleaner.

Repeat this process with all spark plugs. Clean first, then reinstall and insert the lead or ignition switch into the cylinder. If you ask how to clean spark plugs with vinegar, or want to know how to clean spark plugs with gasoline, the process is similar to carB cleaner.

This involves removing carbon buildup from the plug with a wire brush and soaking the plug in vinegar or gasoline for a few seconds.

Method 2: Using Blow Torch

A blowtorch can overheat the spark plugs. Therefore, you need to clamp the plug with pliers to extend the length of the plug to prevent scalding your hands.

Use pliers to secure the plug to one end of the ignition coil connection. Hold the plug firmly and do not squeeze it to avoid damaging it. Forceps can only be used for extension. A vise is a better alternative to pliers.

Turn on the knob on the propane button or gas button and place the ignition source in front of the nozzle or press the ignition button. This will ignite and keep burning. Turn the flashlight upward until it begins to produce a blue flame.

Touching burns off all the junk, debris, and oil on the spark plugs. Don’t be afraid to break the plug; They can survive the heat. While rotating the spark plug, continue to burn the spark plug until the electrode and the spark plug end glow red.

Don’t let anything distract you, and don’t let the flashlight burn anything else (only the threaded part of the plug). The burning process can take a few minutes, depending on your flashlight and its temperature.

Allow the spark plug to cool before holding it with your fingers. The plug should be cooled before use. Be careful when handling spark plugs and a blowtorch. The spark plug will return to its standard color long before it cools. To avoid hot hands, leave each plug on for 5 minutes before reinstalling it.

Remember, I asked you to clean the spark plugs at the same time. When the spark plug is cool, reinstall the spark plug and insert the ignition coil or high voltage wire before moving to another one. Continue this process until it has all been cleaned up. Don’t wash one and leave the others.

Method 3: Using Spark Plug Cleaner Tool

Another effective spark plug cleaning method is to use a spark plug cleaner. Cleaning tools are designed for intake and sandblasting spark plugs. This tool is very convenient.

To use this tool, secure the airbag and tighten the clip, then insert the air source. Press the button on the machine, insert the spark plug, and switch the mechanism to sandblasting. Keep shaking the plug so that cleaning tools can blow away any carbon that has accumulated on it. When the sandblasting is complete, switch the machine to air and blow the debris off the plug.

I still suggest you blow the spark plug with an air source. You don’t want debris to land in your cylinder. 

Step 3: Gap the Spark Plug

Depending on your car, you may need to open the spark plug after cleaning. Refer to your car’s manual for specifications.

Carefully insert it between the arm and electrode using a spark plug gauge (gap gauge). Adjust accordingly according to its correct measurement value.

Step 4: Reinstalling The Spark Plugs

Consult the owner’s manual or visit the manufacturer’s website for specified clearance measurements. After determining the measurement, insert the spark plug gap tool into the gap between the outstretched electrode and the spark plug body.

Measure the opening and know whether the clearance should be increased or reduced by prying the valve body further away from the electrode or tapping close to the electrode until accurate specifications are obtained.

Insert and tighten the spark plug. This is essential to avoid cross-threading of plugs. Screwing the spark plug into the socket handle may wear out the thread. Therefore, it is recommended to tighten it by hand first, and then tighten it with the plug and socket.

If you cannot move the plug by hand, connect the socket wrench and tighten it. However, you don’t have to exert too much force on it. Too much use can cause the plugs in the cylinder head to break. If this happens, you need to lower the cylinder head, resulting in the cylinder.

What’s next? Reconnect ignition coil or spark plug wire. Secure the wire firmly to the sheath and then gently connect it to the plug. You will hear a click, indicating that the wire is properly attached to the plug.

If no clicking sound is heard, it indicates that the plug cord is not properly connected to the plug and may be pulled out while driving along the road. So if the wire is not properly secured, pull it up and reinsert it while twisting the wire left and right.

Final Word

When cleaning or replacing an old spark plug, if you see oil on the spark plug lead, be sure to clean the spark plug hole for efficient performance.

You also need to check the spark plug cable; A bad spark plug could be the reason you clean or replace an old one. If it is the culprit and you fail to find the answer, you will end up with the same result even before replacing the defective cable.

At this point, this article provides enough information on how to clean spark plugs. The process is simple, fast, and easy to access.