Unlock the Secret to a Smooth Ride: How to Change Ignition Coil BMW E90

Are you experiencing misfires, rough idling, or a lack of power in your BMW E90? These symptoms could indicate a faulty ignition coil. Replacing the ignition coil is a relatively straightforward DIY project that can save you a considerable amount of money at the mechanic. This guide will walk you through the process of replacing an ignition coil on your BMW E90, providing detailed instructions and helpful tips.

Understanding the Ignition Coil

The ignition coil is a vital component in your car’s ignition system. It transforms the low-voltage electrical signal from the ignition control module into a high-voltage spark that ignites the fuel-air mixture in the combustion chamber. When an ignition coil fails, it can cause a variety of problems, including:

• Misfires: The engine may misfire, resulting in a rough idle, loss of power, and potentially engine damage.
• Reduced Fuel Efficiency: A faulty ignition coil can lead to incomplete combustion, reducing fuel efficiency.
• Engine Stalling: In severe cases, a failed ignition coil can cause the engine to stall.

Tools and Materials You’ll Need

Before you begin, gather the necessary tools and materials. You’ll need:

• New Ignition Coil: Make sure to purchase the correct ignition coil for your specific BMW E90 model.
• Torque Wrench: This ensures you tighten the bolts to the proper specifications.
• Socket Set: You’ll need a variety of sockets, including 10mm, 13mm, and 16mm.
• Ratchet: To loosen and tighten the bolts.
• Extension Bar: To reach tight spaces.
• Pliers: For removing the old spark plug wire.
• Gloves: To protect your hands from grease and dirt.
• Safety Glasses: To protect your eyes from debris.
• Clean Rags: For cleaning up spills and debris.

Steps to Replace the Ignition Coil

1. Identify the Faulty Coil:

• Start by identifying the faulty ignition coil. This can be done by checking for signs of damage, such as cracks, burns, or corrosion. You can also use a diagnostic scanner to check for misfire codes, which can help pinpoint the problem.

2. Disconnect the Battery:

• Always disconnect the battery before working on any electrical components. This prevents accidental shocks and ensures your safety.

3. Locate the Ignition Coil:

• The ignition coils are typically located on top of the engine, near the spark plugs. They are usually black or brown cylindrical components with a wire connector.

4. Remove the Spark Plug Wire:

• Carefully pull the spark plug wire off the ignition coil. It may be necessary to use pliers to help remove the wire.

5. Remove the Ignition Coil Bolt:

• Using a 10mm socket and ratchet, remove the bolt that secures the ignition coil to the spark plug.

6. Remove the Ignition Coil:

• Once the bolt is removed, gently pull the ignition coil straight up and out of the spark plug well.

7. Install the New Ignition Coil:

• Carefully align the new ignition coil with the spark plug well and gently push it down until it seats securely.

8. Secure the Ignition Coil:

• Using the 10mm socket and wrench, tighten the bolt that secures the ignition coil to the spark plug. Be sure to tighten the bolt to the proper torque specification, which can be found in your owner’s manual or online.

9. Connect the Spark Plug Wire:

• Carefully connect the spark plug wire to the new ignition coil. Ensure the wire is securely connected.

10. Reconnect the Battery:

• Reconnect the battery.

11. Start the Engine:

• Start the engine and allow it to run for a few minutes to ensure the new ignition coil is working properly.

Troubleshooting and Common Problems

• Difficulty Removing the Ignition Coil: If you’re having trouble removing the ignition coil, it may be stuck. Try using a penetrating oil to loosen the coil.
• Damaged Spark Plug Wire: If the spark plug wire is damaged, you’ll need to replace it as well.
• Incorrect Ignition Coil: Make sure you purchase the correct ignition coil for your specific BMW E90 model.
• Misfire After Replacement: If you’re still experiencing misfires after replacing the ignition coil, it’s possible that you have a faulty spark plug, a damaged wire, or a problem with the ignition control module.

Important Tips and Considerations

• Use a Torque Wrench: Always use a torque wrench to tighten the bolts to the proper specifications. This prevents overtightening and damaging the parts.
• Clean the Spark Plug Well: Before installing the new ignition coil, clean the spark plug well with a clean rag to remove any dirt or debris.
• Inspect Other Components: If you’re replacing the ignition coil, it’s a good idea to inspect other components in the ignition system, such as the spark plugs and wires, for signs of wear or damage.
• Consult a Mechanic: If you’re uncomfortable performing this repair yourself, consult a qualified mechanic.

Driving After Replacing the Ignition Coil

After replacing the ignition coil, it’s important to drive the car for a few days and monitor its performance. Pay attention to any unusual noises, vibrations, or changes in engine performance. If you notice any problems, contact a mechanic for further diagnosis.

Final Thoughts: Boosting Your BMW’s Performance

Replacing a faulty ignition coil is a vital step in keeping your BMW E90 running smoothly. By following the steps outlined in this guide, you can save money and gain valuable knowledge about your car’s ignition system. Remember to prioritize safety and use the correct tools and materials to ensure a successful repair.

Quick Answers to Your FAQs

Q: How often should I replace my ignition coils?

A: Ignition coils typically last for 50,000 to 100,000 miles. However, factors like driving conditions and maintenance can affect their lifespan.

Q: What are the signs of a failing ignition coil?

A: Common signs include misfires, rough idling, loss of power, reduced fuel efficiency, and engine stalling.

Q: Can I drive my car with a bad ignition coil?

A: It’s not recommended to drive your car with a bad ignition coil for an extended period. It can cause further damage to the engine.

Q: How much does it cost to replace an ignition coil?

A: The cost of replacing an ignition coil can vary depending on the model of your car, the cost of the part, and labor costs.

Q: Can I replace just one ignition coil?

A: Yes, you can replace just one ignition coil if it’s the only one that’s faulty. However, it’s a good idea to inspect the other ignition coils for signs of wear or damage and replace them if necessary.