How To Remove Spark Plugs That Are Stuck: Step By Step

The only way to deal with stuck spark plugs is to remove it. However, removing a seized spark plugs is easier said than done. Removing a stuck spark plug is a process that requires patients. If you screw it up, you could end up with a repair bill of $500 to $1200. The cost of spark plug removal by a mechanic can be costly, especially if you have a broken spark plug.

In this article, we will be discussing how to remove stuck spark plugs. By the end of the article, you should be able to remove the stuck plugs without damaging the cylinder head.

Tools that you will need

  • Penetrating oil
  • Never-seez
  • ⅜ inch ratchet
  • ⅜ inch breaker bar
  • 2 to 6-inch extension
  • 2-inch length of pipe
  • spark plug socket wrench
  • Turpentine

How To Remove Stuck Spark Plugs

The process of removing a stuck sparker will require the proper tools necessary, which are ones listed above. Here is how to remove a stuck sparker.

Step One: Locate The Plugs.

First, you need to know where the plugs are located. Typically the front sparkers will be easier to access than the rear plugs . Depending on the type of vehicle, you can access the rear plugs from under the car.

Find the spark plugs

In some other models, you may need to remove some components first to access them. For instance, to access the glow plugs for 7.3 Powerstroke will require the removal of the electrical connector at the top.

locate the spark plugs

For other vehicle models removing the wiper, tray will make it easier for you to access the sparkers.  Removing the tray should be easy enough on most car models.

Step Two: Apply Penetrating Oil.

First,  spray PB blaster or any other type of penetrating oil you can get. Note that WD-40 isn’t really a penetrating oil but a general-purpose lubricant used as a rust penetrant.

As such, WD-40 will not have the desired effect. After spraying the penetrating lubricant, leave overnight. However, 30 minutes can also be enough in some instances.

Step Three: Tighten The Plugs

tighten the plugs

Tightening the plugs sounds strange, but that’s what you should do. Use a spark plug socket wrench to tighten the plugs. The purpose of doing this is to give the penetrating oil some room to penetrate into the threads.

Step Four: Repeat

Repeat the process of tightening with the spark plug socket wrench and applying penetrating oil. Repeat this process until the spark plugs come off. If you are having problems, start the engine for a short while to provide heat and then let the engine cool before attempting to remove the plugs..

Starting the engine will work for how to remove stuck spark plugs from aluminum head. The reason being that aluminum head expands when heated. This will create a little bit more room for the penetrating oil. 

Let it cool down before trying again. Alternatively, you can use a wrench extension of at least six inches in length on the socket wrench . However, if removing rear sparker from under the vehicle starting the engine may not be a good idea. 

When you are under the car, you will have to rest your hands on the exhaust manifold, which will be hot. Doing the removal while the engine is cold will help prevent burns on your arms. 

Step Five: Clean The Plugs

clean the plugs

Spray the threads and seat to remove any traces of the penetrating oil. You can also blow-dry the threads with compressed air.

Step Six: Install New Plugs.

After removal, you will need to install new ones. Lubricate the threads of the new plugs with never-seez. Also, clean rust from the ports with compressed air before installing the new ones. Try these spark plugs for 5.7 Hemi and try these spark plugs if you are using 5.4 Triton.

Safety Tips

If you decide to start the engine to help with removal process, be careful not to touch the hot exhaust manifold and wait for the engine to cool.

Have a fire extinguisher ready as penetrating oils are flammable, and you may have to put out a fire if applying penetrating oil in an area that reaches high temperatures. When installing new spark plugs, avoid over-tightening them.

Reasons For Seized Or Stuck Spark Plugs

There are several reasons why your spark plugs may become stuck. The first is due to the buildup of carbon in the combustion chamber. This buildup can line the threads, making them difficult to remove.  The buildup of carbon on the threads will occur if the plugs were not appropriately tightened during installation.

Reasons for seized or stuck spark plugs

If the spark plugs are left unchanged for a long time, corrosion can build up in the threads, making them difficult to remove. Most car manufacturers today recommend regular maintenance.

Precautions For Avoiding Stuck Spark Plugs

After removing, it is recommended to replace them with new once. The plugs may have become stuck due to corrosion brought on by age. 

To avoid problems later on, ensure the new sparkers are appropriately tightened. Tightening the plugs will ensure this does not happen.

Something else you can do is regular maintenance. Regular maintenance will help expose any problems with the spark plugs. This should also help prevent corrosion and buildup of other types of debris in the spark plug threads.


From this tutorial, removing stuck spark plugs may seem easy. However, the process can become frustrating very quickly. This is especially if you rush it. Ideally, you should leave the penetrating oil overnight.

Not many people are able to remove seized spark plugs at the first attempt. Thus you may need a few tries before they become loose enough to be removed. Be prepared for some work and also to be patient as this is a process that requires patience. 

Overall, with time and the right set of tools, you should be able to remove your seized spark plugs.

Last Updated on July 2, 2024 by Rifen

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