Main points
- Glow plugs are responsible for heating the combustion chamber in diesel engines, allowing the fuel to ignite more easily, especially in cold conditions.
- Use a socket wrench and a breaker bar to loosen the glow plugs.
- If the glow plug is still stuck, you may need to use a specialized tool to remove it.
The BMW 320d E90 is a popular and reliable vehicle, but like any car, it requires regular maintenance to keep it running smoothly. One essential maintenance task is changing the glow plugs. Glow plugs are crucial for starting the engine in cold weather, and if they fail, you might experience difficulty starting your car, especially in colder temperatures. This guide will walk you through the process of changing glow plugs on your BMW 320d E90, providing detailed instructions and helpful tips.
Why Change Glow Plugs?
Glow plugs are responsible for heating the combustion chamber in diesel engines, allowing the fuel to ignite more easily, especially in cold conditions. Over time, glow plugs can wear out or fail, leading to various issues such as:
- Difficult starting: A faulty glow plug can lead to a long cranking time, especially in cold weather.
- Rough idling: If one or more glow plugs are not functioning properly, it can cause the engine to idle unevenly.
- Reduced fuel efficiency: Faulty glow plugs can affect the combustion process, leading to lower fuel efficiency.
- Engine damage: In severe cases, a failed glow plug can cause engine damage.
Tools and Materials You’ll Need
Before you begin, you’ll need to gather the following tools and materials:
- New glow plugs: Ensure you purchase glow plugs specifically designed for your BMW 320d E90.
- Torque wrench: A torque wrench is essential for tightening the glow plugs to the correct specifications.
- Socket set: You’ll need sockets of various sizes to remove and install the glow plugs.
- Breaker bar: A breaker bar provides extra leverage for loosening the glow plugs.
- Ratchet: A ratchet is needed to turn the sockets.
- Extension bar: An extension bar can provide additional reach for accessing the glow plugs.
- Penetrating fluid: Penetrating fluid can help loosen stubborn glow plugs.
- Clean rags: Clean rags are essential for wiping away any dirt or oil.
- Safety glasses: Always wear safety glasses to protect your eyes from debris.
- Gloves: Gloves protect your hands from dirt and grease.
Step-by-Step Instructions
Now, let’s dive into the step-by-step process of changing your BMW 320d E90’s glow plugs:
1. Prepare the Vehicle: Park your BMW 320d E90 on a level surface and engage the parking brake. Disconnect the negative terminal of the battery to prevent electrical shocks.
2. Locate the Glow Plugs: The glow plugs are located on the top of the engine, near the cylinder head. They are typically arranged in a circle, with one glow plug per cylinder.
3. Remove the Air Intake: To access the glow plugs, you’ll need to remove the air intake. This usually involves loosening a few clamps and pulling the intake hose out of the way.
4. Remove the Glow Plug Covers: The glow plugs are covered by protective caps. Use a socket wrench to remove these caps.
5. Loosen the Glow Plugs: Use a socket wrench and a breaker bar to loosen the glow plugs. Be careful not to damage the surrounding components. If the glow plugs are stubborn, apply penetrating fluid and allow it to soak for a few minutes.
6. Remove the Old Glow Plugs: Once the glow plugs are loose, use a socket wrench to remove them completely.
7. Install the New Glow Plugs: Thread the new glow plugs into the cylinder head. Be careful not to cross-thread them. Tighten the glow plugs to the specified torque using a torque wrench.
8. Reinstall the Glow Plug Covers: Replace the glow plug covers and tighten them securely.
9. Reinstall the Air Intake: Reattach the air intake hose and secure it with the clamps.
10. Reconnect the Battery: Reconnect the negative terminal of the battery.
11. Start the Engine: Start the engine and let it run for a few minutes to ensure everything is functioning correctly.
Troubleshooting Common Problems
While changing glow plugs is a relatively straightforward process, you may encounter some issues. Here’s how to troubleshoot common problems:
- Stuck Glow Plugs: If you’re having trouble removing a glow plug, try applying penetrating fluid and allowing it to soak for a few minutes. If the glow plug is still stuck, you may need to use a specialized tool to remove it.
- Damaged Glow Plug Threads: If the threads in the cylinder head are damaged, you’ll need to repair them before installing new glow plugs.
- Incorrect Torque: Make sure you tighten the glow plugs to the correct torque specifications. Overtightening can damage the glow plug or the cylinder head, while under-tightening can lead to leaks.
Tips for Success
Here are some tips to ensure a smooth and successful glow plug replacement:
- Use the correct tools: Using the right tools is essential for a safe and efficient job.
- Be patient: Changing glow plugs can be time-consuming, especially if you’re dealing with stubborn ones. Be patient and take your time.
- Clean the area: Keep the work area clean and free of debris to prevent contamination.
- Inspect the old glow plugs: Examine the old glow plugs for signs of wear or damage. This can help you identify any potential issues with the engine.
- Check the glow plug wiring: Inspect the glow plug wiring for any damage or corrosion. Replace any damaged wiring.
The Importance of Regular Maintenance
Changing glow plugs is an important part of regular vehicle maintenance. By replacing them as needed, you can prevent potential engine problems and ensure your BMW 320d E90 starts reliably, even in cold weather.
Final Thoughts: A Smooth Ride Ahead
By following these steps and tips, you can confidently change the glow plugs on your BMW 320d E90. Remember to use the correct tools and take your time to avoid damaging any components. Regularly maintaining your glow plugs will ensure your engine runs smoothly and efficiently for years to come.
Top Questions Asked
Q: How often should I change the glow plugs on my BMW 320d E90?
A: The recommended replacement interval for glow plugs on a BMW 320d E90 is around 60,000 miles or every 4-5 years. However, it’s always best to consult your owner’s manual for specific recommendations.
Q: Can I change the glow plugs myself or should I take it to a mechanic?
A: While changing glow plugs is a relatively straightforward task, it does require some mechanical skills and the right tools. If you’re comfortable working on your car, you can certainly do it yourself. However, if you’re not confident in your abilities, it’s best to take it to a qualified mechanic.
Q: What are the symptoms of a bad glow plug?
A: Common symptoms of a bad glow plug include difficulty starting the engine, especially in cold weather, rough idling, reduced fuel efficiency, and engine misfires.
Q: What happens if I don’t replace a bad glow plug?
A: If you don’t replace a bad glow plug, it can lead to further engine damage, including premature wear and tear on other engine components. In severe cases, it can even cause the engine to seize up.