A Guide to Replacing the Ignition Coils on Your 2013-2018 BMW 320i
Experiencing a rough idle or engine misfires? Your ignition coils are the likely cause, and this is a repair you can handle.
- Ignition coil failure is a very common problem for the 2013-2018 BMW 320i, causing misfires, rough idle, and a check engine light.
- This is an extremely easy DIY repair that requires no special tools and can be done in under 30 minutes.
- Always replace all four coils at once and never mix different brands to ensure proper engine performance.
- Driving with a bad coil can cause expensive damage to your catalytic converter; fix it promptly.
Is Your 320i Running Poorly? It Could Be an Ignition Coil
Ignition coil failure is a very common issue on the N20 engine used in the 2013-2018 BMW 320i. These parts work under high heat and constant vibration, and they simply wear out over time. When a coil begins to fail, it can't produce a strong enough spark, causing the engine to run poorly. You will likely see a Check Engine Light and may get a "Drivetrain Malfunction" warning on your screen. The good news is that this is one of the easiest and most affordable DIY repairs you can do on your BMW.
Symptoms of a Bad Ignition Coil
🎬 Watch this overview of bad ignition coil symptoms.The signs of a failing coil are hard to ignore. You will likely experience one or more of the following:
- Engine Misfires: The car may stutter, hesitate, or jerk when you accelerate.
- Rough Idle: You'll feel a distinct shaking or vibration from the engine when the car is stopped.
- Check Engine Light: A misfire will almost always trigger the check engine light. Common codes are P0301, P0302, P0303, or P0304, indicating a misfire in cylinders 1, 2, 3, or 4, respectively.
- Loss of Power: With one cylinder not firing correctly, your car will feel noticeably sluggish.
- Worse Gas Mileage: Your engine burns more fuel to compensate for the lack of power, so you'll be visiting the gas station more often.
Don't Wait to Replace a Bad Coil
While you can drive short distances with a bad coil, it's not a good idea. When a cylinder misfires, unburned fuel can get into your exhaust system. This can overheat and destroy your catalytic converter, turning a simple, inexpensive fix into a very expensive one.
Choosing the Right Aftermarket Ignition Coil
You do not need to buy a part with a BMW logo on it to get excellent quality. Several companies that supply BMW directly also sell the same parts under their own brand name. For the N20 engine, the original equipment (OEM) supplier has changed over the years, including brands like Bosch, Delphi, and most recently, Eldor.
Critical Tip: Replace All Four and Don't Mix Brands
It is highly recommended to replace all four ignition coils at the same time. They all have the same amount of wear, so if one has failed, the others are likely to fail soon. It is also critical that all four coils are the same brand. Different brands can have minor electrical differences that can cause running issues.
Here’s a breakdown of the available aftermarket brands:
- Bremi & Hella: Both are well-respected German companies that are original equipment suppliers to many European car brands. They are considered a reliable, high-quality choice for your BMW.
- Denso: A top-tier Japanese OEM supplier known globally for high-quality ignition and fuel system components. Denso is an excellent alternative to German brands.
- Beck Arnley: This company is a repackager, not a manufacturer. They often source their parts from the OEM supplier, so you might find an Eldor or Bosch coil in a Beck Arnley box. They are generally a good option.
- Facet: A standard aftermarket brand offering a cost-effective replacement part.
Ignition Coil Replacement Cost
This is an inexpensive repair, especially if you do it yourself. The parts are affordable and labor at a shop is minimal due to how easy the job is.
| Part Type | Price Range (Set of 4) | Notes |
|---|---|---|
| New OEM (Dealer) | $260 - $400 | This is for Genuine BMW-branded parts from a dealership. |
| New Aftermarket | $158 - $317 | Based on the provided price range of $39.43 - $79.19 per coil. Quality varies by brand. |
| Shop Labor | $73 - $107 | Typically less than one hour of labor. |
Frequently Asked Questions (FAQ)
Is replacing the ignition coils a DIY job? 🎬 Watch this step-by-step spark plug and ignition coil replacement guide.
Yes, absolutely. This is one of the easiest jobs you can do on your 320i. The coils are right on top of the engine. You simply pull off the plastic engine cover, unplug the electrical connector on the coil, and pull the coil straight out. No tools are required.
How do I know which ignition coil is bad? 🎬 See an easy trick to diagnose an engine misfire.
The best way is to use an OBD-II scanner to read the check engine light code. A code like 'P0302' means the misfire is on cylinder 2. If you don't have a scanner, you can swap the suspected bad coil with one from another cylinder. For example, swap the coils from cylinder 1 and 2. If the misfire moves to cylinder 1, you've confirmed the coil is bad. Remember, cylinder 1 is at the very front of the engine.
Should I replace my spark plugs at the same time?
It's an excellent idea. You already have everything apart, and old spark plugs can put extra strain on new ignition coils. If your spark plugs haven't been changed in the last 50,000-60,000 miles, you should replace them. Note that you will need a special 14mm 12-point thin-wall spark plug socket for this.
Do I need to put dielectric grease on the new coils?
No. High-quality aftermarket coils come with the correct amount of dielectric grease already applied inside the boot. Adding more can actually cause a poor connection to the spark plug.
Are there any recalls for the ignition coils on my 320i?
No, there are no specific safety recalls for ignition coils on the 2013-2018 BMW 320i. While other recalls exist for this vehicle, they do not involve the ignition coils.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12138657273 12138616153 12138647689 12137594937 12131712219
Coil-on-plug design, 3-pin electrical connector, SAE connector type.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- BMW 320i: