How To Clean Spark Plug & Hole? [What Happens & Solutions]

Spark plugs are just another minor part of their vehicle for many drivers. But remember, this tiny component is critical to the effective operation of your vehicle.

You must clean the wells regularly to ensure that they are in good working order. Otherwise, it may harm your car’s performance and cause various issues.

Despite its compact size, this component is responsible for supplying the spark that drives your car’s engine. It can pick up a lot of dirt and oil if kept filthy.

If this build-up develops, your engine may break down, resulting in combustion misfiring and damage to your valuable automotive parts. So, in this article, you’ll learn how to clean spark plug holes so that your car stays in great shape.

Why Do You Need to Clean a Spark Plug Hole?

Any small engine or fuel-powered vehicle needs healthy spark plugs to run at efficient and consistent speeds. Cleaning the spark plugs is one of the first steps in diagnosing a problem when your engine misfires, comes to a halt, or won’t start in the first place.

You may wish to replace the entire spark plug in many circumstances because it is a reasonably inexpensive fix. On other occasions, you may be lucky to escape big problems by simply cleaning and reinstalling the spark plug.

If your spark plug is constantly clogging due to oil leaking or incorrect carburetor jetting, you’ll want to wait until the problem is resolved before installing fresh new spark plugs.

Otherwise, you’ll end up replacing spark plugs only to discover that they’re covered in grease and fouled once more. That is why you should think about cleaning the old plugs.

What Happens If Spark Plugs Are Dirty?

A small amount of oil isn’t a problem, but if there’s a lot of it in the engine, it can harm the car’s catalytic converter and the plug. It can also cause the engine to lock up, known as hydro locking.

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This circumstance in which the engine cannot compress the fluids in the vehicle may potentially cause catastrophic damage to the vehicle.

There are also terrible possibilities, such as when spark plugs tarnish to the point of breaking. Your car could be seriously damaged due to the breakdown, requiring complete repair.

As a result, it’s critical to clean it regularly; otherwise, you’ll have to replace a lot more than just cleaning materials for your car.


When the spark plugs don’t fire properly, the engine may run rough and fail to start. In your car, you are recommended to use high-quality spark plugs constantly.

Poor Engine Acceleration

Your car’s ability to accelerate can be limited by dirty spark plugs, making it more difficult to get up to speed. So, always maintain the cleanliness of your spark plugs.

Damage to Engine

In extreme circumstances, allowing dirt and debris to accumulate in the spark plug hole can cause extensive engine damage. What you’ll need in that situation is complete repair.

Supplies Needed in Cleaning a Spark Plug Hole

If you detect oil in the plug wells when you remove the spark plugs, you should remove it immediately since it will cause an engine to misfire if it sits there too long.

Remove any loose objects or grease from your plug wells using this guide. Cleaning the spark plug hole will necessitate the use of a few materials. These are some of them:

  • Gentle cleaning brush
  • Air gun
  • Cleaner for carbs
  • Wrench
  • Screwdriver
  • Sandpaper
  • Huge screwdriver
  • Tool for cleaning spark plugs
  • Fresh rag
  • Wrench for spark plugs
  • Safety glasses

How to Clean A Spark Plug Hole?

It’s a brilliant idea to start preparing a cleaning session if you find oil or debris in your spark plugs during your valve inspections. The steps for preserving them are outlined below.

Step 1: Remove Battery (Negative Terminal)

First and foremost, safety. Make sure your battery’s negative terminal is disconnected before you begin. Don’t skip this step; it’s normal for mechanics and other car maintenance.

To accomplish this, unscrew the nut and secure it with a wrench. You can now stand back and prepare to clean your spark plug hole after removing the negative terminal.

Step 2: Locate Spark Plugs

It would be best to locate the ignition coils or high-tension lead cables. Trace the wires to find the spark plug tubes. Each cylinder will have one cable and one spark plug.

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If you’re having trouble finding the spark plug tubes in your car, consult your owner’s or service manual.

Step 3: Use any tool to blow out debris on the surface

After you’ve located the spark plug holes, you’ll need to clear out all of the dirt and debris to prevent it from dropping into the tubes. Blow out any loose materials around the opening with your air gun. Make sure to use your safety glasses.

Step 4: Disconnect Ignition Coils/Cables one by one

You must remove the ignition coils one at a time to avoid introducing more debris and crud into the spark plug holes rather than removing them. Take a firm grip on the ignition coil and gently turn and pull it off.

Step 5: Utilize Spark Plug Socket

Fix your wrench on the extension once you’ve fixed the spark plug socket. Place the socket on the spark plug tube and twist it counter-clockwise to liberate the spark plug. After you’ve broken it free, remove the wrench and unscrew it by hand.

Step 6: Use Air Gun for Spark Plug

Cleaning your spark plug hole using an air gun is the most effective way to remove dirt, debris, or any other loose material from the spark plug tubes.

This procedure inserts the air cannon tip into the spark plug hole and blows out any debris or sludge inside.

Step 7: Use A Screwdriver and a Carb Cleaner

The oil on the spark plug or ignition coil indicates oil in the spark plug tubes. To remove oil from the spark plug holes, spray carb cleaner into the hole, then dip a big screwdriver and a clean towel into the spark plug Wells to remove the oil.

To avoid pouring too much carb cleaner into the spark plug tubes, spray it on a clean rag instead of spraying it within the plug wells. Clean the area several times to ensure that all oil has been removed.

Step 8: Clean and Set Spark Plug Gap

After cleaning the spark plug holes, use a spark plug cleaning tool, wire brush, or sandpaper clean spark plugs. Whichever route you choose, make sure the spark plugs are well cleaned.

Consult your owner’s manual for the recommended spark plug gap measurement. You should then insert the gap tool between the spark plug and the electrode.

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Measure the gap, then press down or pry the electrode until it meets the vehicle’s standards.

Step 9: Place Spark Plug and Tighten with Socket Wrench

The spark plug wrench contains a rubber grommet that holds the plug in place, allowing you to replace the spark plugs without closing the gap effortlessly.

Let’s say your plug wrench is missing the rubber grommet. You’ll have to replace the spark plug by hand carefully.

Using a socket and extension, snug the spark plug by hand. After you’ve snugged the spark plug by hand, connect your ratchet handle to tighten it properly. Make sure the spark plug is securely fastened.

Step 10: Reinstall Coils and Wires

Reinstall the ignition coil or plug wire using the reserving procedure. Everything, including the battery terminals, must be secured. Then start your engine and let it idle for a few minutes to check for any errors.

Other Tools in Cleaning Your Spark Plugs


A piece of 220-grit sandpaper is required. Start sanding by slipping the sandpaper beneath the bent section of the electrode. You want to clean the metal of any discolored build-up. Back and forth with the sandpaper until you see bare metal on the tip.


Any spark plug parts that are filthy should be filed down. To clean every dark corner, insert the file between the spark plug and the electrode. Remove any build-up with a file until you can see the clean metal underneath.

Wire Brush

Scrub the threads of the spark plug using a wire brush. This procedure will remove any oil or filth from the engine, making it easier to reinstall. To remove most of the dirt, wipe in the same direction as the threads, then switch sides to finish the job.

Blow Torch

Wear gloves to safeguard your hands from the flames and hot metal. Turn on the blowtorch and place the spark plug right in the middle of the flame.

Spark plugs are designed to endure extreme temperatures, such as those found within a hot engine.

Any residual oil or gasoline build-up on the plug will be ignited by the flames and burned away. Turn it around to ensure that the plug is evenly exposed to the flame.

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Importance of Cleaning the Spark Plug Hole

The first step in keeping your car tuned and functioning at its best is to check the condition of your spark plugs.

Additionally, the most important purpose of a spark plug in your engine is to create an electrical spark that ignites gasoline and air in your engine’s combustion chamber, causing the pistons to move up and down.

Internal heat, gasoline, and oil, among other things, can cause the spark plug to wear out and limit its effectiveness. Worn-out spark plugs must work harder to get the same outcomes as new, well-gapped plugs.

Spark Plug Maintenance Tips (After Care)

YouTube video

When your spark plugs become clogged or corroded, it can cause various issues, including poor gas mileage, slow acceleration, engine misfires, and difficulty starting the engine.

Looking at your spark plugs is a smart place to start if you’re having engine troubles. You can watch the video above for spark plug maintenance tips.

Use a compressed air cannon to blow away any dirt or debris accumulated around the exterior before replacing the old spark plug.

Check for cracks in the porcelain if it has been dropped. Make sure the side electrode is straight and aligned with the center electrode.

Spray the cavity around the center electrode with carburetor cleaner while the plug is facing downward to allow any material to fall out.

Any porcelain dust or debris from the manufacturing process that could cause a misfire, especially under load, will be removed.

Lastly, a dielectric compound should be applied to the secondary wire connection and the porcelain insulator where the boot sits to avoid corrosion and prevent the boots from clinging to the insulator, leading to wires breaking in the future.

A Quick Guide To Spark Plugs

Frequently Asked Questions (FAQs):

How do you use carb cleaner?

To remove oil from the spark plug holes, spray carb cleaner into the hole and then clean it out with a large screwdriver and a clean rag. The only method to keep oil out of the valve cover is to replace the worn gasket.

Can you use a carb cleaner in Spark Plugs Hole?

You can use a carb cleaner to melt hardened material and tiny debris in spark plug tubes and then remove them using an air gun.

However, rather than pouring the carb cleaner directly into the spark plug holes, it is recommended to spray it on a clean towel and dip it within them.

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How do you clean spark plug hole threads?

Getting a thread chaser or a back tap and using these instruments after you’ve thoroughly aired out the threads is an excellent solution.

This step is not an exercise you should do regularly but rather when you see a significant build-up of dirt.

Does WD-40 Work as a cleaning agent for Spark Plug Hole?

The WD stands for Water Displacement, which implies the water is pushed out of the way.

You can use WD-40 to eliminate moisture from a wet spark plug or liquid surrounding the igniter as part of your cleaning routine. It also cleans the electrode of any carbon residue that has accumulated.

How to know when it’s time to clean the Spark Plug’s hole?

Your best option should be to consult the instruction manual. Because each car is built differently, the cleaning period will vary. Generally, most automobiles require the replacement of spark plugs every 30,000 miles.

Takeaway: Cleaning the Spark Plugs Hole

That’s all that you need to know about cleaning spark plug holes. If you have trouble cleaning the spark plug hole, consider cleaning it every time you change your spark plugs.

This way, they’ll work properly in the future, reducing engine overheating.

Cleaning spark plug holes regularly will also save you the trouble of rebuilding your engine later.

If you cannot clean a spark plug hole yourself, take your car to a mechanic and request that the spark plug hole be cleaned. To keep your engine in top condition, follow this guide on cleaning spark plug holes.

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