How to Replace N55 Spark Plugs in Your BMW

Spark plugs are a vital component of any combustion engine, including the BMW N55 engine. Over time, spark plugs can wear out and affect your vehicle's performance. Replacing the spark plugs in your BMW N55 engine is a relatively straightforward task that you can tackle yourself with a few basic tools and some patience. In this guide, we'll walk you through the step-by-step process of replacing the spark plugs in your BMW N55 engine, helping you maintain optimal engine performance and fuel efficiency.

You can buy these plugs HERE.

Here are the tools we will use to complete this job:

• E18 E-Torx Socket - Buy Here

• 10mm Socket - Buy Here

• T30 Torx - Buy Here

• Torque Wrench - Buy Here

• 14mm Spark Plug Socket Tool - Buy Here

• Socket Wrench - Buy Here

• Socket Extension - Buy Here

• Spark Plug Gapping Tool - Buy Here

Step 1: Preparation

Ensure that the engine is cool before starting any work. Open the hood and locate the engine cover. Carefully remove the engine cover to gain access to the ignition coils.

Step 2: Removing the Ignition Coils

Locate the ignition coils on top of the engine. They are usually attached to the valve cover. Start by disconnecting the electrical connectors from each ignition coil. Then, using a socket and extension, remove the bolts securing the ignition coils. Gently pull the ignition coils upward to detach them from the spark plugs. Set them aside in a clean and safe place.

Step 3: Removing the Old Spark Plugs

With the ignition coils removed, you'll now have direct access to the spark plugs. Using a spark plug socket and an extension, carefully loosen and remove each spark plug one at a time. Be cautious not to damage the threads or the surrounding components. Inspect the old spark plugs for signs of wear, such as excessive carbon buildup or electrode erosion.

Step 4: Preparing and Installing New Spark Plugs

Before installing the new spark plugs, check the gap on each plug using a spark plug gap tool. Adjust the gap as necessary to meet the manufacturer's specifications. Apply a small amount of dielectric grease to the spark plug's threads and carefully insert it into the spark plug socket. Slowly thread the new spark plug into the cylinder head by hand to avoid cross-threading. Once snug, use the spark plug socket and torque wrench to tighten the spark plug to the recommended torque specified in your vehicle's manual. Repeat this process for each spark plug.

Step 5: Reinstalling Ignition Coils and Engine Cover

With the new spark plugs installed, it's time to reattach the ignition coils. Place each ignition coil back onto its respective spark plug. Ensure they are fully seated and aligned properly. Insert and tighten the bolts to secure the ignition coils in place. Reconnect the electrical connectors to each ignition coil. Finally, reinstall the engine cover by carefully aligning it and pressing it back into place.

Congratulations! You have successfully replaced the spark plugs in your BMW N55 engine. Regularly replacing your spark plugs will help maintain optimal engine performance, fuel efficiency, and smooth operation. By following this step-by-step guide and using the recommended tools and materials, you can confidently perform this maintenance task yourself, saving time and money. However, if you feel uncomfortable or unsure at any point during the process, it's always best to consult a professional mechanic. Enjoy the enhanced performance and reliability of your BMW with fresh spark plugs!