A Guide to the Serpentine Belt on Your 2008-2018 Audi S5
Understand the symptoms of a failing serpentine belt and how to choose the right replacement for your S5's V8 or V6 engine.
- A squealing noise is the most common early warning sign of a problem with the serpentine belt system.
- For a reliable repair, always replace the serpentine belt, tensioner, and idler pulleys together as a kit.
- Continental is an OEM supplier for Audi, making it a top choice for aftermarket replacement belts.
- Replacement is a labor-intensive job on the S5 that requires moving the front of the car into a "service position."
Is Your Audi S5 Serpentine Belt Failing?
A serpentine belt has a limited lifespan and will wear out over time due to heat and constant use. The general replacement interval is between 50,000 and 90,000 miles, but you should start visually inspecting it during oil changes after 50,000 miles. Look for cracks, fraying, glazing, or missing pieces of rubber.
Common symptoms of a failing belt or tensioner include:
- Squealing Noises: A high-pitched squeal or chirp from the engine bay, especially on cold starts or when you rev the engine, is a classic sign of a slipping or worn belt.
- Accessory Failure: You may notice the battery warning light on your dash (alternator is not charging), heavy or difficult steering (power steering pump has lost power), or the A/C blowing warm air.
- Overheating: On some engines, the water pump is driven by the serpentine belt. If the belt fails, the engine can overheat quickly.
Tensioner and Pulley Issues
Often, a squealing noise isn't the fault of the belt itself, but a failing belt tensioner or idler pulley. These components keep the belt tight. It is highly recommended to replace the belt, tensioner, and any idler pulleys as a complete kit to ensure the longevity of the repair.
Choosing the Right Aftermarket Serpentine Belt
For a high-performance vehicle like the S5, choosing a quality replacement belt is critical. You don't need to buy a part from the dealer to get excellent quality.
Brand Quality Tiers
- OEM Supplier (Tier 1): Brands like Continental (Contitech) and INA are original equipment manufacturers for Audi. A Continental belt is often the same part you would get from a dealership, just without the Audi logo. INA is a trusted OEM for tensioners and pulleys. Choosing these brands ensures a perfect fit and factory-grade performance.
- High-Quality Aftermarket (Tier 2): Brands like Gates and Dayco are well-respected in the industry and produce reliable belts that meet or exceed OEM specifications. They are a dependable choice and are widely available. For European vehicles, many mechanics have a slight preference for Continental, but Gates and Dayco are also excellent options.
When shopping, look for serpentine belt "kits." These kits bundle the belt with the necessary tensioner and idler pulleys, which is the correct way to service the system and prevent a repeat failure.
🎬 Watch a professional mechanic replace the Audi S5 serpentine belt.Serpentine Belt Replacement Cost for Audi S5
The cost to replace the serpentine belt on an S5 is higher than on many other vehicles, primarily due to labor. The tight engine bay, especially on the 4.2L V8, requires a technician to put the car in a "service position" by removing the front bumper and moving the radiator support forward to gain access. 🎬 See how to properly put your Audi into the service position. This adds significant time to the job.
| Part Type | Estimated Cost |
|---|---|
| New OEM Belt | $61 - $85 |
| New Aftermarket Belt | $17 - $73 |
| Shop Labor | $250 - $600 |
| Total Estimated Cost (Aftermarket Kit) | $350 - $800+ |
Cost estimates are for the belt and/or kit plus labor and will vary by location and shop.
Frequently Asked Questions
Can I just replace the belt and not the tensioner?
While you can, it is not recommended. The tensioner and pulleys wear out at a similar rate to the belt. A worn tensioner can cause a new belt to fail prematurely, leading to the same problem again in a short time. Replacing them as a kit is the best practice.
Are there any recalls for the Audi S5 serpentine belt?
No, there are no active recalls from the NHTSA for the serpentine belt system on the 2008-2018 Audi S5. Recalls for this vehicle range primarily concern airbags and seat belt systems.
Is this a difficult DIY job?
Yes, for most home mechanics, this is a difficult job. Unlike many cars where the belt is easily accessible, the S5 requires significant disassembly of the front end to gain clearance. This job is best left to an experienced DIYer or a professional mechanic.
What is the difference between the 4.2L V8 and 3.0T V6 belt systems?
The primary difference is that the 3.0T engine uses a second, separate belt to drive its supercharger. The main serpentine belt still drives the other accessories like the alternator and A/C. The 4.2L V8 uses a single serpentine belt for all its accessories. 🎬 Watch this step-by-step drive belt replacement for the 4.2L V8 engine. The replacement procedure and access issues are similar for both.
Helpful Videos
Technical Specifications
OEM Part Numbers: 079903137AA 079903137AB 06E903137R 06E903137Q
Belt construction is typically EPDM (ethylene propylene diene monomer) rubber with polyester tensile cords. Length and number of ribs vary by engine (4.2L V8 vs. 3.0T V6) and accessory configuration.
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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 S5: