Spark Plug Won’t Come Out – A Detailed Explanation

Your vehicle’s ignition system comprises many pieces necessary for starting a car. The spark plug is one of the most crucial components.

When a spark plug won’t come out, it can cause serious issues with your vehicle.

A clogged spark plug can be extremely inconvenient, especially if you’re repairing your car. This article will provide reasons and solutions for a stuck spark plug. Let’s read until the end for valuable tips.

What Is A Spark Plug?

spark plug won’t come out

A spark plug is an integral part of the car’s internal combustion engine that provides a spark to ignite the air and fuel combination.

This component features a threaded shell made of metal that protrudes into the combustion chamber and is connected to the engine’s ignition system.

The spark occurs at the spark plug’s tip, which ignites the air/fuel mixture to start the engine.

The spark plug’s tip has an electrode connected to the ignition. When the engine operates, this electrode generates an electric spark that leaps a small distance to the ground electrode.

This spark will ignite the air-fuel mixture, allowing the engine to run smoothly.

What Makes Spark Plug Won’t Come Out?

You can’t get spark plug out? A stuck spark plug can happen for various reasons, such as carbon accumulation, corrosion, engine temperature, oil, and failed ignition coil.

This issue can make you annoyed when repairing the engine.

Carbon Buildup

The first reason is carbon accumulation in the combustion chamber. This deposit can clog the plug threads.

Carbon will accumulate on the plugs that are not properly tightened. You need to check the installation steps carefully to ensure everything is correct.

Spark Plug Corrosion

If you don’t change or touch the spark plugs for a long time, it is an ideal condition for corrosion to deposit in its threads.

You will need to apply a lot of force to be able to break the structure of this corrosion. That’s why your spark plugs cannot come out.

This problem is annoying during the repair process and affects the operation of this part. Thus, experts recommend car owners have regular maintenance to prevent the issue.

Rising Temperature 

The metal head and the plug are not made of the same material. As the temperature in the vehicle’s engine rises, they don’t expand at the same pace.

\The aluminum head can expand bigger than the spark plug.

When you try to take off the plugs while they are in this state, they frequently become attached to the aluminum head, leading to stuck problems.


If the spark plug is in an area with a lot of oil buildup (close to the valve cover), it might be oil-coated.

This oil that accumulates over the day will harden and cause the oil-fouled spark plug, which is challenging to remove.

Malfunctioning Ignition Coil

A malfunctioning ignition coil will trigger excessive voltage levels to deposit on your bad spark plug, making it stuck to the engine.

How To Remove Seized Spark Plugs

How to get a stuck spark plug out

How to get a stuck spark plug out? Let’s check this section for some useful methods.

A Breaker Bar

This is the most commonly used method for removing a seized or trapped spark plug. This method doesn’t require you to do more steps. Instead of using a wrench, let’s try a breaker bar.

The breaker bar exerts greater force than a conventional wrench, which might aid in the removal of the spark plug.

Penetrating Oil

How to remove a seized spark plug? Penetrating oil is a useful way to try.

If the spark plug has been trapped in the engine, penetrating oil can assist in freeing it.

The oil’s characteristic can break down the corrosion or stubborn dust and lubricate the screw threads, allowing you to remove it easier.

A Heat Gun

A heat gun is a handheld device that emits hot air at temperatures ranging from 100 – 550 °C (200-1000 °F), with some better models reaching temperatures as high as 760 °C.

Thus, a heat gun can help dislodge the engine’s spark plug by using high temperature to decay corrosion or rust inside. Be careful when using a heat gun since it can harm your spark plug or engine.

A Vice Grip

This tool the right-hand man many DIYers require. The locking feature lets them be clamped firmly while you make a cut, measure, or remove a stripped bolt. Various vice grips resemble a heavy-duty pair of pliers.

As a result, you can use the vice grip to grab the spark plug’s body and spin it free from the engine. This procedure should only be chosen as the last resort because it can wreak havoc on the threads or engine.

After removing the spark plug, clean any dirt or deposits that accumulate on the electrodes with a sandpaper or wire brush. If the electrodes are substantially fouled, the spark plug may need to be replaced.

If you are having trouble removing a blocked or stuck spark plug, it is recommended to seek assistance for a spark plug repair.

They have the necessary tools and skills to remove the spark plug without hurting the engine.

How To Avoid A Spark Plug Not Coming Out


The most crucial thing is choosing a suitable spark plug (the correct size spark plug and high-quality type) for the car engine. Buying an improper one can create many issues, such as stuck plugs.

You should double-check the spark plugs’ gaps to ensure they are properly placed. A gap that is too large or too small can bring about ignition issues.


First, you need to take the spark plug off. Loosen the plug wires and remove the caps from the top of the plugs to accomplish this. Then, remove it from the car engine with a wrench.

Next, clean the plugs’ exteriors with a brush or a rag. Ensure all debris and grease are erased from the plugs’ surface.

Then, you need to clean the plug holes with a wire brush or a drill. Remember to eliminate all dust and corrosion.

In the next step, use a rag to scrub the plugs’ electrodes. You can combine applying WD-40 to get the best result.

Finally, reattach this component to the car engine by reversing all steps.


When a spark plug won’t come out, it may be due to various reasons: corrosion, temperature, oil, etc.

A trapped or fused spark plug makes it challenging to remove it. However, a few approaches can be utilized to take off the impediment.

If the plugs are severely rusted, you should replace them. Cleaning spark plugs is a very simple chore, but it is critical to do it correctly to guarantee that the plugs work properly and ensure fuel economy.

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