How to fix a blown out spark plug?

How to fix a blown out spark plug?


When a spark plug blows out, it can cause significant issues with the engine’s performance. This problem is commonly encountered in older vehicles or those with high mileage. If you find yourself facing a blown out spark plug, it’s essential to address the issue promptly to prevent further damage and restore your engine’s optimal functioning. In this article, we will discuss the steps to fix a blown out spark plug and get your vehicle back on the road.

Identifying a Blown Out Spark Plug

Before diving into the repair process, it is crucial to identify whether you are indeed dealing with a blown out spark plug. Some common signs include misfiring engine, loss of power, rough idling, and a loud popping sound from the engine. Additionally, you may notice oil or carbon deposits around the spark plug area. Once you have confirmed the issue, you can proceed with the repair process.

Materials Needed

To fix a blown out spark plug, you will need the following materials:

– Spark plug thread repair kit: This kit typically includes a tap, insert, and installation tool. It is essential to choose a kit that matches your spark plug’s thread size.
– Socket set: A socket set with the appropriate size for removing the spark plug.
– Ratchet: A ratchet will be used to loosen and tighten the spark plug.
– Threadlocker: Threadlocker helps secure the insert in place and prevent it from coming loose.
– Anti-seize compound: Applying anti-seize compound to the spark plug threads helps prevent future issues.

Repair Process

Follow these steps to fix a blown out spark plug:

1. Safety first: Ensure the engine is cool before starting the repair process. Disconnect the vehicle’s battery to avoid any accidental electrical discharge.

2. Remove the spark plug: Use a socket set and ratchet to carefully remove the blown out spark plug from the cylinder head. Be cautious not to damage the threads or drop any debris into the cylinder.

3. Clean the spark plug hole: Use compressed air or a vacuum cleaner to remove any debris or foreign particles from the spark plug hole. This step is crucial to ensure a proper fit for the insert.

4. Tap the spark plug hole: Use the tap from the spark plug thread repair kit to create new threads in the spark plug hole. Make sure to align the tap properly and apply gentle pressure while turning it clockwise. Remove the tap and clean any metal shavings from the hole.

5. Install the insert: Take the insert from the thread repair kit and apply threadlocker to the external threads. Use the installation tool to screw the insert into the spark plug hole until it is flush with the cylinder head.

6. Reinstall the spark plug: Apply a small amount of anti-seize compound to the spark plug threads and carefully thread it into the newly installed insert. Use a torque wrench to tighten the spark plug to the manufacturer’s specifications.


Fixing a blown out spark plug is a relatively straightforward process that can be done with the right tools and a little patience. By following the steps outlined in this article, you can successfully repair a blown out spark plug and restore your engine’s performance. Remember to exercise caution during the repair process and consult a professional if you are unsure or uncomfortable with performing the repair yourself.