A BMW 750i Owner's Guide to Ignition Coil Replacement (2006-2019)
Eliminate engine misfires and restore the smooth, powerful performance of your BMW 750i's V8 engine.
- A failing ignition coil is a very common cause of misfires, rough idle, and power loss on the BMW 750i.
- For best results, replace all eight coils and spark plugs at the same time, not just the one that failed.
- Stick with high-quality, OEM-supplier brands like Delphi, Bosch, or NGK. Delphi is often the preferred choice due to a history of better reliability.
- Avoid budget brands like URO Parts for this critical component, as forum consensus points to a high risk of premature failure.
Is Your BMW 750i Running Rough? It Could Be an Ignition Coil.
A failing ignition coil is one of the most common reasons for a BMW 750i to develop a rough idle, hesitate during acceleration, or lose power. Because the V8 engines in these cars are sensitive to ignition timing, even one faulty coil can significantly impact performance and drivability. Fortunately, diagnosing and replacing an ignition coil is a straightforward job that many owners can do themselves.
Warning: Do Not Ignore a Misfire
While you can technically drive with a bad ignition coil, it's not recommended for long. A misfiring cylinder can dump unburned fuel into the exhaust system, which can quickly overheat and destroy your expensive catalytic converters, turning a minor repair into a major expense.
Symptoms of a Failing Ignition Coil
When a coil starts to go bad, the signs are usually obvious. Look out for:
- Engine Misfires: The engine may stutter, hesitate, or jerk, especially when you accelerate. 🎬 Watch a real-world diagnostic and test drive for N63 misfires.
- Rough Idle: Your car may vibrate or shake noticeably when stopped and in gear.
- Check Engine Light: A failing coil will almost always trigger the check engine light. A scanner will typically show codes from P0300 (random misfire) to P0301-P0308 (indicating a misfire on a specific cylinder). 🎬 Check out this quick tip for diagnosing engine misfires.
- Loss of Power: Your 750i will feel sluggish and less responsive than usual.
- Reduced Fuel Economy: The engine's computer tries to compensate for the misfire, often by using more fuel.
Choosing the Right Aftermarket Ignition Coil
Not all aftermarket coils are created equal. For a high-performance vehicle like a BMW 750i, choosing a quality part is essential. The brands available can be grouped into tiers.
Tier 1: OEM-Equivalent and High-Quality Brands
These brands are known to either be the original equipment manufacturer (OEM) for BMW or produce parts that meet or exceed OEM standards. For peace of mind and long-term reliability, these are your best choices.
- Delphi: BMW began using Delphi as a primary supplier after some original Bosch coils showed higher failure rates. Many in the BMW community consider Delphi the go-to replacement for reliability. A technical service bulletin even instructed dealers to replace failing Bosch coils with Delphi parts on some models.
- Bosch: As the original supplier for many years, Bosch is a well-known option. While they had a period of reported issues, many owners still use them without problems, and they remain a major OEM supplier.
- NGK: Famous for their spark plugs, NGK also produces high-quality ignition coils. They are a trusted name in the performance and import vehicle community.
- Eldor: This is another OEM supplier for modern BMWs and is considered a top-quality choice, often used on newer and high-performance models.
Tier 2: Budget Brands
This category includes brands like URO Parts, DriveWire, and other lower-cost options. While the price is tempting, forum discussions and owner experiences frequently describe these parts as lower quality, with a much higher risk of premature failure. For a critical component like an ignition coil on a 750i, saving a few dollars here often leads to doing the job twice. It is generally recommended to avoid these brands for this specific part.
Pro Tip: Replace in Sets
If one ignition coil has failed due to age and heat, the others are likely not far behind. To save yourself time and future headaches, it is highly recommended to replace all eight ignition coils at the same time. It is also the perfect time to replace your spark plugs, as you already have everything taken apart.
Cost of Replacing BMW 750i Ignition Coils
| Item | Estimated Cost |
|---|---|
| New Aftermarket Coil (Per Coil) | $30 - $96 |
| New OEM Coil (Per Coil) | $75 - $150 |
| Shop Labor (Per Hour) | $125 - $250 |
| DIY Replacement (8 Coils + Plugs) | $400 - $900 (Parts Only) |
| Shop Replacement (8 Coils + Plugs) | $1200 - $2500+ (Parts & Labor) |
Frequently Asked Questions
Can I replace just the one bad coil?
You can, but it's not recommended. Ignition coils are exposed to the same heat and wear. If one has failed, the others are likely weakened and may fail soon, requiring you to do the job again. Replacing all eight at once is the most reliable repair.
Is this a difficult job to do myself?
For most mechanically inclined owners, this is a very manageable DIY job. The coils are located on top of the engine and are accessible after removing the plastic engine covers. The job typically requires basic hand tools and can be completed in under two hours.
🎬 See this step-by-step walkthrough for replacing coils and plugs.What's the difference between Bosch and Delphi coils?
Bosch was the original supplier for many BMWs. Due to some reliability concerns, BMW later began using and recommending Delphi coils, which many owners now prefer. Both are considered quality brands, but Delphi is often seen as the updated, more reliable choice for this generation.
What other parts should I replace at the same time?
It is standard practice to replace all eight spark plugs when you replace the ignition coils. The labor is nearly identical, and fresh plugs ensure the new coils perform optimally. Always check for the correct spark plug type for your specific 750i model year.
Do I need to use dielectric grease?
Yes, applying a small amount of dielectric grease to the inside of the new coil boot is recommended. This helps protect against moisture and makes it easier to remove the coil in the future.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12138616153 12137594937 12138647684 12137571643
This vehicle uses one 'pencil' style ignition coil per cylinder, for a total of eight coils. They are located directly on top of the valve cover, connecting the vehicle's wiring harness to the spark plug.
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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.
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