Ignition Coil Guide for 2014-2016 BMW M235i
Keep your M235i's N55 engine running smoothly by understanding when and how to replace your ignition coils.
- Stick to OEM-quality brands like Bosch, Delphi, NGK, or Eldor for your M235i to ensure reliability.
- It is highly recommended to replace all six ignition coils and spark plugs at the same time to prevent future issues.
- A flashing check engine light indicates a severe misfire; pull over immediately to prevent catalytic converter damage.
- This is a simple DIY replacement that can be done in under an hour with basic tools, saving you on labor costs.
Is Your M235i Stumbling? It Could Be an Ignition Coil.
The ignition coils on the N55 engine in your 2014-2016 M235i are robust but don't last forever. Heat and vibration eventually take their toll, and failure is common as the miles add up. When a coil starts to fail, it can't produce the strong spark needed for proper combustion. This leads to noticeable problems like engine misfires, a rough idle, and a general loss of power. You'll likely see a check engine light and may get fault codes related to misfires on specific cylinders (e.g., P0300-P0306).
🎬 Watch: A guide to common symptoms of a bad ignition coil.Known Issues & TSBs
A BMW Technical Service Bulletin (TSB), SI B12 15 15, notes that it's common to find corrosion on the metal heat shield of the Delphi ignition coils used in the N55 engine. This is caused by moisture entering the spark plug area. BMW states that this corrosion does not affect the coil's function, so you don't need to replace a coil just because it looks rusty. 🎬 See this helpful tip for diagnosing a BMW engine misfire. No major recalls have been issued for ignition coils on this model.
Choosing the Right Aftermarket Ignition Coil
When shopping for a replacement, you'll find a wide range of brands and prices. For a performance car like the M235i, it's not the place to cut corners. Cheap, unproven brands can fail quickly and may even cause damage to your engine's computer (DME). It's best to stick with brands known for their quality and reliability.
Brand Quality Tiers for BMW M235i
- Tier 1: OEM Supplier Brands (Recommended): These brands are often the original equipment manufacturers for BMW. They offer the same quality as the part you'd get from a dealership, but without the high price tag. For the N55 engine, Bosch and Delphi are the primary OEM suppliers. Many owners and technicians also trust NGK and Eldor, with Eldor being a supplier for newer BMW models. Choosing any of these is a safe bet for reliability and performance.
- Tier 2: Reputable Aftermarket Brands: Brands like Standard Ignition and Hitachi produce reliable parts that meet or exceed OEM specifications. They are a solid choice if OEM-supplier brands aren't available.
- Tier 3: Budget Brands: This category includes brands like DriveWire, True Tech, and other generic store brands. While the low price is tempting, their quality can be inconsistent. Using these parts on a high-performance engine like the N55 is a risk that can lead to more problems down the road.
Pro Tip: Replace in Sets
If one ignition coil fails, the others are likely not far behind. They have all been exposed to the same heat and wear. To ensure consistent performance and avoid future misfires, it's highly recommended to replace all six ignition coils at the same time, especially if your car has over 60,000 miles. It's also a good idea to replace the spark plugs at the same time if they are due.
How Much Does an Ignition Coil Replacement Cost?
The cost can vary depending on the brand of parts you choose and whether you do the work yourself or hire a professional. The replacement is a simple DIY job for most home mechanics.
| Item | Estimated Cost |
|---|---|
| New OEM (from dealer) | $70 - $100 per coil |
| New Aftermarket (OEM quality) | $35 - $65 per coil |
| Shop Labor | $98 - $143 |
| Total Professional Replacement (All 6 Coils) | $400 - $800+ |
Frequently Asked Questions
Can I drive with a bad ignition coil?
It's not recommended. Driving with a misfire can cause unburnt fuel to enter the exhaust, potentially damaging your expensive catalytic converter. If the check engine light is flashing, you should stop driving and have the vehicle serviced as soon as possible.
How difficult is it to replace the ignition coils on an M235i?
This is a very DIY-friendly job. The coils are located directly on top of the engine and are easily accessible after removing the engine cover. The process involves unplugging the electrical connector, pulling the old coil out, and pushing the new one in. It typically takes less than an hour to replace all six.
🎬 Watch: Step-by-step walkthrough for replacing M235i spark plugs and coils.Should I use dielectric grease on the new coils?
Yes, applying a small amount of dielectric grease to the inside of the coil boot where it meets the spark plug is a good practice. It helps with installation and prevents moisture from getting in, but do not apply it to the electrical connector pins.
Do I need to mix and match brands?
No, you should not mix different brands of ignition coils. Different brands can have slightly different internal resistance and performance characteristics. Always replace coils in a full set with the same brand to ensure balanced engine performance.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12138616153 12137594937 12138657273
Coil Type: Pencil Coil, Connector: 3-pin
We Have This Part in Stock
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 M235i:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your M235i Stumbling? It Could Be an Ignition Coil.
- Known Issues & TSBs
- Choosing the Right Aftermarket Ignition Coil
- Brand Quality Tiers for BMW M235i
- Pro Tip: Replace in Sets
- How Much Does an Ignition Coil Replacement Cost?
- Frequently Asked Questions
- 🎟️ Get 5% Off