How to Remove a Broken Bolt from an Engine Block – 4 Simple Steps

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Working on the engine block or the systems around the engine is not an easy task. You might have the best intentions to fix something, but it is too common to break a bolt or dislodge a broken bolt.

Knowing how to remove a broken bolt from an engine block becomes critical because the work of removing such a bolt becomes more important than the repair. Otherwise, it can cause extensive wear and tear and also affect the other bolts in the engine block due to vibration.

How to remove a broken bolt from an engine block?

how to remove a broken bolt from an engine - Man with Wrench

Today, we will share the step-by-step procedure and provide multiple solutions to this problem.

While trying to remove a broken bolt, it is necessary to use proper methods to prevent further damage. The procedure below will help you with that.

Step 1: Use the center punch to mark the spot:

The first thing is to mark the spot. This should be the center of the bolt. To do the same, you will use a center punch to mark the spot before moving on to the next step.

Step 2: Drill the screw center:

After that, you have to start drilling at that spot. The size of the drill bit is essential. It should be such that it provides a proper grip and ensures that the drill bit does not damage the vicinity of the screw. Choose the drill bit accordingly and start the drilling.

Step 3: Remove particles using a magnetic screwdriver:

While drilling, there will be a lot of metal residue. While you will be removing the pieces of the screw with the extractor, it is not that easy to remove the residue.

So, use a magnetic screwdriver and move it around the screw. That will attract all the magnetic particles to the screwdriver and pull them out.

Step 4: Use a screw extractor to remove it:

After that, you can close the screw extractor into the broken bolt and remove it. If you cannot fit the screw extractor into it, you must step up the drill bit size and drill again before lodging the screw extractor into it.

When using the screw extractor, try to dislodge it by moving the screw extractor, or if that doesn’t work, you have to try the unscrewing motion and remove the bolt pieces easily.

These four simple steps can remove the bolt from the engine block.

Many times, it might happen that the bolt you are trying to remove has a broken head.

In that case, the above method will be very difficult to execute. We will share with you a technique for the same below.

How do you remove a bolt when the head is broken?

Removing a bolt with a broken head seems like a Herculean task. However, with the right procedure and tools, you can do so in a short time.

Step 1: Mark the center of the remaining bolt piece:

Use the center punch to mark the exact center of the bolt like in the method above.

Step 2: Drill in the opposite turn direction:

Drill at the center of the bolt piece so that the threads are in the opposite direction.

Step 3: Insert new bolt:

You need to drill till as close to the bottom as possible. Once you have done so, insert the bolt in the center of the bolt piece.

Step 4: Tighten till the bottom:

Go on tightening the bolt till it reaches the bottom. Once it reaches the bottom, the older bolt piece will loosen up, and you can simply pull it out.

Thus, even if the head of the bolt is broken, removing it is still possible.

What is the best tool to remove a broken bolt?

The screw or bolt extractor is one of the best ways to remove the broken bolt. Rather than comparing hundreds of tools to find the best one, you can simply go with a 5 Pcs Screw Extractor Kit. It is the best in the category since it offers features like:

  • The kit offers five different pieces, which means that you will be able to remove any kind of bolt.
  • The extractor pieces are made from high-quality alloy steel, which means they have a pretty long lifespan.
  • These extractor pieces can help you remove damaged bolts and trimmed bolts.
  • They are designed to work with most drills, so there are no compatibility issues.

Considering these factors, there is no doubt that this extractor kit is one of the best ways to remove broken bolts.

How do you remove a broken bolt without an extractor?

You can use a vise grip rather than an extractor to remove a broken bolt.

Step 1: Lubricate the bolt:

Since this method will use brute force to unscrew the broken bolt, it is essential to lubricate it first. It will certainly reduce the friction.

Step 2: Use a vise grip to unscrew it:

With the help of the vise grip, you have to hold the bolt and move the vise grip so that it is unscrewed. Even if the head of the bolt is broken, you can still unscrew it with this method.

This method will require considerable time and effort to remove the bolt, but you can certainly do so.

How do you remove a broken bolt from an aluminum block?

The four-step method we have highlighted to remove broken/damaged bolt from the engine block is also applicable to the bolt in the aluminum block. The four steps include:

  • Step one: Use the center punch to mark the right spot
  • Step two: drilling the screw center
  • Step three: removing any residue using a magnetic screwdriver
  • Step four: Use the screw extractor to remove the broken bolt

Following these four steps will ensure that you can also remove the broken bolt from an aluminum block.


How to remove a broken bolt from an engine block might seem pretty difficult. However, with the right procedure, you can do so in no time.

If you’re experiencing such a problem, refer to our guide above, and you will never have to worry about the broken bolt again. The methods highlighted above ensure that the engine block or the aluminum block is not damaged in any way, and still, you can extract the broken bolt.

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