Blog

Spark Plug Thread Repair

Spark Plug Thread Repair

Spark plug threads can become damaged for a number of reasons, including:

Overtightening the spark plug

Using the wrong size spark plug

Cross-threading the spark plug

Corrosion

If a spark plug thread is damaged, it can prevent the spark plug from being properly seated, which can lead to engine misfires. In some cases, a damaged spark plug thread can even cause the spark plug to shear off, which can be a major repair.

The good news is that it is possible to repair a damaged spark plug thread. There are a few different methods that can be used, but the most common is to use a spark plug thread chaser.

A spark plug thread chaser is a tool that is used to clean and repair damaged spark plug threads. It is a small, cylindrical tool with a threaded end that matches the size of the spark plug thread. The tool is threaded into the spark plug hole and then rotated to clean and repair the threads.

To repair a damaged spark plug thread, you will need a spark plug thread chaser, a lubricant, and a torque wrench.

Instructions:

Clean the spark plug hole with a wire brush.

Apply a lubricant to the spark plug thread chaser.

Thread the spark plug thread chaser into the spark plug hole until it is flush with the cylinder head.

Rotate the spark plug thread chaser back and forth to clean and repair the threads.

Remove the spark plug thread chaser and inspect the threads. The threads should be clean and free of damage.

Install a new spark plug and torque it to the specified spec. See this blog to know when new spark plugs are needed. https://www.meyersautotech.com/spark-plug-replacement/

Safety Precautions:

Be sure to use the correct size spark plug thread chaser. Using the wrong size chaser can damage the threads further.

Do not overtighten the spark plug thread chaser. Overtightening can damage the threads.

Use a lubricant to prevent the spark plug thread chaser from binding.

Tips:

If the spark plug threads are severely damaged, there are thread replacement options. But you may need to replace the cylinder head.

As you can see in the photos, this one did not go according to plan. It also had some Internal Engine issues as well but that’s another seminar…

Want to try it yourself? I wish you the best. Follow the proper steps and you will be successful. But if you find it a little too much. Give us a call, we can help!!

Spark plug thread repair
Auto Repair Kennewick WA
Related Posts