Audi S4 Ignition Coil Guide for 1992-2003 Models
Solve misfires and restore lost power by choosing the right ignition coil for your C4 or B5 generation S4.
- First, confirm if you have a C4 (1992-94) with a single coil or a B5 (2000-02) with six individual coils.
- For the B5 S4, it is strongly recommended to replace all six coils at once to prevent future failures.
- OEM-equivalent brands like Beru, NGK, and Delphi offer the best reliability and performance for the S4 engine.
- Replacing ignition coils is a very simple DIY job that can be done in under 30 minutes with basic or no tools.
Understanding Your S4's Ignition System: C4 vs. B5
Before buying an ignition coil, you must know which Audi S4 you own. The 1992-2003 range covers two very different cars in North America.
- C4 Audi S4 (1992-1994): This model has a 2.2L 5-cylinder turbocharged engine (engine code: AAN). It uses a single ignition coil pack that sends power to the spark plugs through spark plug wires.
- B5 Audi S4 (2000-2002): This model features a 2.7L V6 bi-turbo engine (engine code: APB). It uses a modern coil-on-plug system with six individual ignition coils, one for each spark plug. This system is known for coil failures, making it a common replacement item.
Important: The 2003 model year marked the start of the B6 S4 with a V8 engine. These V8 models use different ignition coils not covered here. Always verify your engine type before ordering.
Signs of a Failing Ignition Coil
When an ignition coil starts to fail, your car's performance will suffer. On the B5 S4, a single bad coil can make the car almost undrivable, while a failing coil on the C4 will affect all cylinders. Common symptoms include:
- Check Engine Light: A failing coil will almost always trigger the check engine light. You may see codes like P0300 (random misfire) or P0301-P0306 (misfire on a specific cylinder).
- Engine Misfires: The engine may sputter, shake, or jerk, especially when you try to accelerate. This can feel like a sudden loss of power.
- Rough Idle: Your car may vibrate or run unevenly when stopped.
- Reduced Power & Fuel Economy: Your S4 will feel sluggish, and you'll notice you're using more gas than usual.
- Backfiring: In some cases, unburned fuel can explode in the exhaust, causing a loud popping sound.
Choosing the Right Aftermarket Ignition Coil
Not all aftermarket brands are created equal. For a high-performance engine like the S4's, choosing a quality coil is important for reliability. Aftermarket brands can be grouped into tiers.
Pro Tip: Replace in Sets
For the B5 S4, it is highly recommended to replace all six ignition coils at the same time. If one coil has failed due to age and heat, the others are likely to fail soon after. This saves you from repeated repairs.
Tier 1: OEM & OE-Equivalent Brands
These brands are known to be Original Equipment Manufacturers (OEM) for Audi and other German automakers. They offer the best quality and reliability, often identical to the part you'd get from a dealer.
- Beru: Widely considered an OEM supplier for Audi ignition components. A top choice for reliability.
- NGK: A trusted name in ignition systems, known for high-quality coils and spark plugs.
- Delphi: A major OEM supplier with a strong reputation for durable and reliable electronic parts.
Tier 2: Quality Aftermarket Brands
These brands are well-established in the aftermarket and offer a good balance of price and quality. They are a solid choice for owners looking for a reliable part without the OEM price tag.
- Standard Ignition (SMP): A long-standing brand with a generally positive reputation for reliable components.
- Walker Products: A known aftermarket manufacturer that produces a wide range of engine management parts.
Tier 3: Value-Focused Brands
These brands compete on price and are best for those on a tight budget. While they can function correctly, their long-term durability may not match that of higher-tier brands. Owner reviews are often mixed.
- URO Parts: Known for being a budget-friendly option, but quality can sometimes be inconsistent.
- DriveWire, Global Parts, Skyward, Spectra: These are often private-label brands that offer a low-cost alternative. They can be a viable option, but be aware that you may be trading longevity for a lower initial cost.
Cost of Replacing an Audi S4 Ignition Coil
| Part Type | Estimated Cost (Per Coil) |
|---|---|
| New OEM | $60 - $160 |
| New Aftermarket | $27 - $85 |
| Shop Labor | $50 - $100 |
Frequently Asked Questions (FAQ)
Is it difficult to replace an S4 ignition coil?
No, this is one of the easiest jobs you can do. On the B5 S4, the coils are directly on top of the engine. You simply unplug the electrical connector and pull the coil straight up. The C4's single coil is also easily accessible. The entire job typically takes less than 30 minutes.
🎬 Watch this step-by-step guide on replacing your B5 S4 coil packs.Are 'performance' red-top ignition coils worth it?
For most owners with stock or lightly modified cars, standard OEM-quality coils from brands like Beru or NGK are more than enough. So-called 'R8 coils' are a popular modification but often require adapters and provide little to no benefit on an otherwise stock engine.
Were there any recalls for S4 ignition coils?
While Volkswagen and Audi had widespread recalls for ignition coils on other engines (like the 1.8T and 3.0L), the 2.7T in the B5 S4 and the 2.2T in the C4 S4 were generally not included in these major campaigns. Some vehicles may have had coils replaced under specific Technical Service Bulletins (TSBs) for misfire issues.
Should I also change my spark plugs?
Yes, it is an excellent idea to replace your spark plugs at the same time you replace your ignition coils. Worn spark plugs can put extra strain on the coils, causing them to fail prematurely. Since you already have the coils out, replacing the plugs adds very little extra time or effort.
Helpful Videos
Technical Specifications
OEM Part Numbers: 034905105 034905101 058905105 078905104A
Ignition System Type: C4 S4 (1992-1994) uses a single coil with spark plug wires. B5 S4 (2000-2002) uses a coil-on-plug direct ignition system.
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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 S4:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Understanding Your S4's Ignition System: C4 vs. B5
- Signs of a Failing Ignition Coil
- Choosing the Right Aftermarket Ignition Coil
- Pro Tip: Replace in Sets
- Tier 1: OEM & OE-Equivalent Brands
- Tier 2: Quality Aftermarket Brands
- Tier 3: Value-Focused Brands
- Cost of Replacing an Audi S4 Ignition Coil
- Frequently Asked Questions (FAQ)
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