A Guide to Replacing Ignition Coils on the 2020-2024 Audi S8
Experiencing misfires or a check engine light on your twin-turbo V8? Your ignition coils may be the culprit.
- A misfire code (P030X) is the most common sign of failure, but a TSB warns it can also indicate a more serious internal engine issue.
- Due to 2-4 hours of labor to access the coils, it is strongly recommended to replace all 8 coils and spark plugs at the same time.
- OEM-equivalent brands like Bosch and Delphi offer factory quality without the dealer markup and are recommended for this vehicle.
- If the check engine light is flashing, pull over and have the vehicle towed to prevent expensive catalytic converter damage.
Is Your S8's Engine Acting Up?
A rough idle, hesitation when you accelerate, or a sudden check engine light can be frustrating in a high-performance vehicle like the Audi S8. These are common signs that one or more of your ignition coils are failing. Due to the high heat generated by the twin-turbo V8, ignition coils are considered a wear-and-tear component that will eventually need replacement.
Symptoms of a Failing Ignition Coil
When a coil starts to go bad, the spark it produces becomes weak or inconsistent. This prevents the fuel in that cylinder from burning properly, leading to a misfire. You might notice one or more of the following issues:
- Check Engine Light: This is the most common sign. A diagnostic scan will usually show a misfire code, such as P0300 (random misfire) or P0301-P0308 (indicating a misfire in a specific cylinder). 🎬 See how to troubleshoot a specific cylinder misfire code.
- Rough Idle: The engine may shake or vibrate more than usual when the car is stopped.
- Engine Hesitation: When you press the gas, the car may feel sluggish, jerky, or slow to respond.
- Reduced Fuel Economy: An engine that isn't running efficiently will burn more fuel.
- Flashing Check Engine Light: If the light is blinking, it signals a severe misfire that is dumping unburned fuel into the exhaust. Stop driving immediately to prevent catastrophic damage to your expensive catalytic converters.
Important: A Misfire Isn't Always a Bad Coil
Audi has issued a Technical Service Bulletin (TSB 13 20 09 / 2060876/1) for the 2019-2021 S8 (and other models with the 4.0T V8). It warns that a random misfire code (P030000) can sometimes be caused by corrosion on the cylinder walls, which is a much more serious internal engine issue. If you replace a coil and spark plug and the misfire does not go away, professional diagnosis is required.
🎬 Watch a professional technician diagnose a complex Audi S8 misfire.Choosing the Right Aftermarket Ignition Coil
For the 2020-2024 S8, you have several good aftermarket options. Since brands like Bosch are often the Original Equipment Manufacturer (OEM), their aftermarket parts provide the same quality without the dealership price tag. Here’s how the available brands generally stack up:
- OEM-Equivalent Brands (Tier 1): Bosch and Delphi are excellent choices. They are major OEM suppliers known for reliability and performance that matches the factory part. You can install these with confidence, knowing they meet Audi's specifications.
- Quality Aftermarket (Tier 2): Standard Ignition (SMP) is a well-respected brand. Their parts are known to be reliable replacements, and their Blue Streak line is often engineered to improve upon original weaknesses, such as better seals to prevent moisture damage.
- Economy Brands (Tier 3): Brands like DriveWire, Global Parts, and Holstein offer a more budget-friendly price point. While they can be a viable option for a quick repair, some owners on forums report a higher failure rate with lower-cost coils, sometimes leading to recurring misfire problems. For a high-performance engine like the S8's, investing in a Tier 1 or Tier 2 brand is often worth the extra cost for long-term peace of mind.
Pro Tip: Replace Coils and Plugs Together
The ignition coils on the 4.0T V8 are buried under wiring harnesses and other components, making the replacement a labor-intensive job of 2-4 hours. Since coils and spark plugs have a similar service life, it is highly recommended to replace all eight coils and all eight spark plugs at the same time. This saves you from having to pay for the same difficult labor charge again in the near future when another old coil fails.
Cost of Replacing Audi S8 Ignition Coils
The total cost will depend on the parts you choose and your shop's labor rate. Your S8 requires eight individual coils.
| Part/Service | Estimated Cost |
|---|---|
| New OEM Ignition Coils (Set of 8) | $440 - $600 |
| New Aftermarket Coils (Set of 8) | $290 - $530 |
| Shop Labor | $300 - $900 |
| Total Estimated Cost | $590 - $1,430 |
(Cost estimates are for a full set of 8 coils and do not include spark plugs.)
Frequently Asked Questions
Can I just replace the one bad ignition coil?
Yes, you can. However, ignition coils tend to fail around the same time. Because accessing the coils on the S8 requires 2-4 hours of labor, most owners and mechanics choose to replace all eight at once to avoid repeating the costly repair when the next coil fails.
Are there any recalls for the 2020-2024 S8 ignition coils?
No, there are no specific recalls for ignition coil failure on the 2020-2024 Audi S8. There is an important Technical Service Bulletin (TSB) that notes misfire codes can sometimes point to a more serious engine issue, not just a bad coil.
Is this a DIY job?
For an experienced DIY mechanic, it is possible. However, it is more complex than on many other cars. It involves removing engine covers, braces, and carefully moving large wiring harnesses to access the coils. Given the complexity and the risk of damaging plastic clips, many owners prefer to have a professional handle this job.
🎬 Watch this detailed walkthrough of the 4.0T coil and plug replacement.I replaced the coil, but the misfire is still there. What now?
If a new coil and spark plug don't fix the misfire in a specific cylinder, the problem could be a faulty fuel injector or, in a worst-case scenario, a mechanical engine problem like the one described in Audi's TSB 13 20 09. At this point, professional diagnosis with a compression test is recommended.
Helpful Videos
Technical Specifications
OEM Part Numbers: 079905110P 06H905110P 06H905110L 06H905110H
This vehicle uses eight individual coil-on-plug style ignition coils. Each coil is secured by one T30 Torx bolt.
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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.
- Audi S8:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your S8's Engine Acting Up?
- Symptoms of a Failing Ignition Coil
- Important: A Misfire Isn't Always a Bad Coil
- Choosing the Right Aftermarket Ignition Coil
- Pro Tip: Replace Coils and Plugs Together
- Cost of Replacing Audi S8 Ignition Coils
- Frequently Asked Questions
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