How To Clean Spark Plug Well – 10 Steps Guide

How To Clean Spark Plug Well

Without a clean spark plug, your car won’t run smoothly. Cleaning the spark plug and its holes properly will ensure your car’s long-life cycle and also save you bucks. Thus, knowing how to clean spark plug well is a must to avoid unnecessary problems with your car engine.

In this article, we have detailed each of the steps for your convenience.

How to Get Oil Out of Spark Plug Well

Before cleaning the spark well, you need to gather the following things –

  1. Large screwdriver
  2. Sandpaper
  3. Carb cleaner
  4. Compressed air
  5. Cloth for cleaning
  6. Spark plug socket including extensions
  7. Gap tool
  8. Safety glasses

Once you have gathered all the materials, you are all ready to start cleaning your spark plug holes by following the steps below –

1. Detach the Negative Terminal of the Battery

Before you get into cleaning the spark plug well, you need to disconnect the negative battery terminal. It can be found either in the hood or engine bay of your car. You can take off the terminal by detaching the bolt and keeping the terminal.

2. Detect the Spark Plug Tubes

You can find the spark plugs connected to the ignition coil. Usually, there is only one coil and spark plug for each cylinder. If you have trouble finding the ignition coil, please refer to your car’s user manual.

3. Use Compressed Air to Clean the Surrounding Surface

Once you find the spark plug, you should clean the nearby debris. If there is dirt while cleaning the spark plug holes, some of it may fall into the hole and damage your car engine. So, it is better to clean out all the dirt around the holes using compressed air and use safety glasses while doing so.

4. Remove the Ignition Coils

After cleaning all the dirt around the surface, it is time for you to take off the ignition coils. Please make sure to pull them off one by one and store them when they are removed. Otherwise, you might face problems while putting back the ignition coils.

5. Take off the Spark Plug Wires

Spark plug wires are fragile. So, you have to carefully loosen up the spark plug using the spark plug socket. Once it becomes free, gently pull off the spark plugs from the holes.

6. Clean the Spark Plug Well

Now, you can clean the dirty spark plug well in multiple ways. The easiest way is with the help of compressed air. For this, you will need a can of compressed air with a long tip so you can thoroughly clean the bottom of the spark plug well.

Even if you clean off all the dirt in the spark plug holes, the cleaning is not done yet. Next, you have to know how to remove oil from spark plug well. As this oil cannot be cleaned by compressed air, you will need a large screwdriver, a clean rag, and a carb cleaner.

First, spray some carb cleaner into the spark plug well. You can spray some carb cleaner on the cleaning rag too. Either way will work for you.

After that, wrap the rag around the tip of the screwdriver. Now, please put it into the spark plug well and gently stir around the walls to soak up all the oil. You will have to repeat this process for all holes until all the oil is cleaned up.

Also, please note that normally you can’t find oil in spark plug well. If there is oil, it means that you have a bad valve cover gasket. To avoid getting oil in the holes again in the future, you will have to replace the valve cover gasket.

7. Clean the Spark Plugs

After the spark plug well is cleaned, you need to clean the spark plugs properly.

For cleaning the spark plugs, it is better to use 220 grit sandpapers to clean off all the dirt from them.

8. Set the Spark Plug Gap

Before you set the spark plug gap, please refer to your car’s user manual to get the recommended spark plug gap for your car. If you can’t find it, generally, the gap is set between 0.6 mm to 1.8 mm.

But, be careful as setting the gap too low will cause the engine to run poorly. And if the gap is too high, your engine may misfire. So, it is best to go along with the recommended specifications for your car.

For setting the gap, push the gap tool in the space between the plug electrode and the spark plug. Now move the tool until it matches your convenient specifications.

9. Put Back the Spark Plugs

You can place the spark plugs either by hand or using a spark plug socket and extensions. It is safer to do it using a spark plug socket as you might not be able to fix the spark plugs properly by hand.

Now, fit the spark plug to its original location with the help of the spark plug socket and required extensions. After that, you may use your hand or a ratchet handle to tighten the spark plug. Either way, remember to do it gently, as putting too much pressure might cause the spark plug to break.

Before moving onto the final step, make sure the spark plug is perfectly placed back in its original position. Otherwise, you will face problems starting your engine later on.

10. Reattach the Ignition Coils

After securing the spark plugs, it is finally time for you to put back everything together. Take your ignition coils, and reconnect them in the exact order you removed them. Finally, reconnect the negative terminal of the battery.

After all the steps are done, please try to start your engine and check for any problems.


You have to follow some precautions before or during cleaning the spark plug well:

  • Always wear safety glasses while using compressed air. Otherwise, the debris might get into your eyes.
  • After removing the ignition coils, put them back in the correct order after cleaning. If the order is changed, your engine will face starting problems.
  • Spark plugs are fragile. Unless you are using a spark plug socket to loosen the spark plugs, please apply minimum pressure while working with the spark plug by hand.


Do I need to use a cleaner to clean the spark plug well?

Using carb cleaner is not a must while cleaning the spark plug well. However, it will make the cleaning process a lot easier for you. Using a carb cleaner loosens up all the junk stuck in the spark plug well, which you can easily clean with a rag.

Without carb cleaner, you will face many difficulties while taking out the hardened dirt or oil stains in the spark plug holes. During that process, you might even damage your engine. So, it is highly recommended that you use a carb cleaner while cleaning the spark plug holes.

Is it necessary to clean the surface around the spark plug well?

Yes, you should clean the surface around the spark plug well before taking out the spark plugs. If there is any debris remaining on the surface when you take out the spark plugs, the debris may fall into the holes and damage your engine without you knowing.

Thus, you should clean the surface properly to ensure the future safety of your engine.

How to find out the recommended spark plug gap for my engine?

You can find the required specifications for your spark plug gap in the user manual that comes with your car. If you don’t have the manual, it is better to contact your car’s manufacturer.

Setting the gap too low or high might cause your engine to function improperly or even misfire.

Can I use any alternatives for cleaning the spark plugs other than sandpaper?

Other than sandpaper, there are many more ways to clean spark plugs. You can even get a spark plug cleaning tool from car maintenance stores. If you don’t want to use that, you can use a wire brush to scrub all the dirt or oil off your spark plugs.


Even though you don’t need to clean the spark plugs that frequently, you are advised to clean them every once in a while, to avoid getting them dirty; doing so will ensure your engine’s smooth running and save you from unnecessary troubles.

Knowing how to clean spark plug well is a must when owning a car. So, follow the instructions of this article properly to gain experience on how to clean your spark plug well.

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