A Guide to Replacing Ignition Coils on the 2018-2022 BMW M5 (F90)
Keep your M5's high-performance S63 engine running smoothly by understanding its ignition coils.
- Ignition coil failure is a common maintenance item on the F90 M5, often causing misfires, rough idle, and a check engine light.
- For a high-performance engine like the S63, choosing a quality aftermarket brand like Delphi is a reliable, cost-effective alternative to expensive OEM parts.
- It is highly recommended to replace all eight coils and spark plugs at the same time to ensure consistent performance and avoid future repairs.
- Be aware of potential coolant leaks from the expansion tank, as this can cause corrosion and premature failure of the coils below it.
Understanding Ignition Coil Failure in Your M5
Ignition coils are wear-and-tear items. The intense heat and vibration in the M5's engine bay eventually cause them to break down. A failing coil can't produce the strong spark your engine needs, leading to a range of noticeable problems. Common signs include a rough idle, hesitation when you accelerate, and a general loss of power. You will almost certainly see the Check Engine Light illuminate, with diagnostic trouble codes pointing to an engine misfire (P0300-P0308).
Known Issue: Coolant Tank Leaks
Some F90 M5 owners have experienced leaks from the coolant expansion tank, which is located above some of the ignition coils on the driver's side. Dripping coolant can fall onto the coils and seep into the spark plug wells, causing corrosion and premature coil failure. If you notice corrosion on the coils under the tank, inspect the tank and its connections immediately.
Choosing the Right Aftermarket Ignition Coil
When replacing ignition coils on your M5, you have a choice between Original Equipment (OEM) and aftermarket parts. OEM coils, often made by brands like Eldor or Bosch for BMW, offer a guaranteed fit and performance. Aftermarket coils can be a more budget-friendly option, but quality can vary significantly. For a high-performance engine like the S63, it's crucial to choose a reputable aftermarket brand.
- Tier 1 (OEM Supplier Quality): Delphi is a well-known OEM supplier that manufactures parts to high standards. Many BMW owners and shops consider Delphi coils a reliable alternative to the dealer part, sometimes even believing they offer improved reliability over other OEM brands that may have failed prematurely. They are designed as a direct-fit replacement.
- Tier 2 (Reputable Aftermarket): Brands like Spectra offer coils made with premium copper and are engineered to meet high standards. They provide a cost-effective solution that is widely available.
- Tier 3 (Economy): Brands like URO Parts and DriveWire fall into the economy category. While attractively priced, forum discussions suggest their reliability can be inconsistent for high-performance applications. Some users reserve these brands for less critical components or for older vehicles where cost is the primary concern. For an M5, especially one that is driven hard, investing in a higher-tier coil is strongly recommended. 🎬 Watch this guide on upgrading to Dinan performance ignition coils.
Pro Tip: Replace in Sets
Because all eight coils operate under the same conditions, they tend to have a similar lifespan. If one coil fails, others are likely not far behind. To save on future labor and ensure consistent performance, it is highly recommended to replace all eight ignition coils at the same time, especially if the vehicle has over 40,000-50,000 miles or is tuned.
Cost of Replacing Ignition Coils
| Part Type | Price Range (Per Coil) | Notes |
|---|---|---|
| New Aftermarket | $36.14 - $96.05 | Price varies by brand quality. |
| New OEM (Dealer) | $60 - $125 | Genuine BMW parts are the most expensive option. |
| Shop Labor | $200 - $400 (for all 8) | Labor can take 2-4 hours. Some owners report the job is more difficult than on other BMWs. |
Frequently Asked Questions
Should I replace my spark plugs at the same time?
Yes. The labor to access the ignition coils is the same as for the spark plugs. Since spark plugs are also a critical wear item, replacing them at the same time as your coils is efficient and considered best practice for maintaining engine health. 🎬 Follow this step-by-step tutorial for replacing your S63 spark plugs. Worn spark plugs can even cause new ignition coils to fail prematurely.
Is this a DIY-friendly job?
For an experienced DIY mechanic, yes. However, the F90 M5's engine bay is very compact. The job requires removing engine covers, and on the driver's side, the coolant expansion tank must be moved to access the rear coils. The Digital Motor Electronics (DME), the car's main computer, must also be disconnected and moved. Some owners report the job taking up to 6 hours due to the tight access. 🎬 See how to navigate the engine bay in this DIY video. If you are not comfortable with this level of work, it is best to leave it to a professional.
What happens if I don't replace a bad ignition coil?
Ignoring a failing ignition coil can lead to more serious problems. A consistent misfire allows unburned fuel to enter the exhaust system, which can overheat and damage the expensive catalytic converters. It also causes poor performance, terrible fuel economy, and can potentially leave you stranded if the car stalls.
Are there any recalls for the 2018-2022 M5 ignition coils?
My search did not find any specific recalls or Technical Service Bulletins (TSBs) from BMW or the NHTSA for ignition coil failure on the 2018-2022 M5. However, individual failures are a known maintenance item.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12138616153 12138647689 12138611236 12137594937
The BMW M5 uses a 'coil-on-plug' direct ignition system, with one individual coil for each of the eight cylinders. This eliminates the need for traditional spark plug wires and provides a more efficient spark.
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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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