A/C Receiver Drier Guide for the 2007-2015 Audi S6
Weak A/C in your S6? The receiver drier is a critical, often-overlooked part you need to understand.
- Crucially, verify your S6 generation: 2007-2011 (C6) use a canister drier, while 2012-2015 (C7) use a desiccant bag.
- The receiver drier MUST be replaced any time the A/C system is opened for service to protect new parts and validate warranties.
- This is not a DIY job. Replacement requires specialized refrigerant handling equipment and should be done by a professional.
- For best results and longevity, choose an OEM-quality brand like Mahle or Nissens.
Is Your S6 A/C Not As Cold As It Used To Be?
When the air conditioning in a high-performance car like the Audi S6 starts to weaken, it's a major frustration. While issues can range from the compressor to a refrigerant leak, a small but crucial component called the A/C receiver drier is almost always involved in a proper repair. Understanding its role is key to getting your A/C blowing ice-cold again.
Critical: C6 vs. C7 Generation Difference
The 2007-2015 model years span two different S6 platforms (C6 and C7), and the receiver drier part is completely different between them. Ordering the correct one is essential.
- 2007-2011 Audi S6 (C6): These models use a traditional, separate canister-style receiver drier. It is a standalone part that is typically mounted near the A/C condenser. The common OEM part number is 4F0820191B or a predecessor.
- 2012-2015 Audi S6 (C7): These models use a modern desiccant cartridge or 'bag' that fits inside a chamber on the A/C condenser itself. This is a serviceable part, but it is not a separate canister. The common OEM part number is 8K0298403A.
You must verify your vehicle's year before ordering to ensure you get the correct part.
Symptoms of a Failing A/C Receiver Drier
A receiver drier doesn't usually fail on its own. Its symptoms mean it has become saturated with moisture or clogged with debris, often from another component failure or just from age.
- Weak or Warm Air: This is the most common symptom. A clogged drier restricts refrigerant flow, preventing the system from cooling effectively.
- Musty or Moldy Smell: When the desiccant is saturated, it can't absorb more moisture. This can lead to mold growth in the evaporator, causing a bad smell from the vents.
- Frost on A/C Lines or Drier: A severe blockage can cause a rapid pressure drop, making the outside of the drier or its lines cold enough to freeze moisture from the air.
- Rattling Noises: In rare cases, the desiccant bag inside the drier can rupture, and the small beads can travel through the system, causing noise.
Choosing the Right Aftermarket Brand
Since the receiver drier must be replaced any time the A/C system is opened, choosing a quality aftermarket part is a smart financial move. Here’s how the available brands stack up for your S6.
Tier 1: OEM-Equivalent Brands
These brands are known OEM suppliers for German vehicles. They offer the best fit, performance, and longevity, often being the same part you'd get from a dealer, just in a different box.
- Mahle: A premier German parts manufacturer and a common OEM supplier for Audi. Choosing a Mahle (or Mahle Behr) drier is the safest bet for OEM quality and perfect fitment.
- Nissens: A well-respected European brand specializing in climate control and cooling components. Nissens parts are known for their high quality and are a reliable alternative to Genuine Audi parts.
Tier 2: Standard Aftermarket Brands
This brand offers a cost-effective solution that meets or exceeds original specifications, providing a good balance of value and performance for most repairs.
- Global Parts Distributors (GPD): A large distributor of aftermarket A/C parts. They provide a direct-fit, budget-friendly alternative to premium brands, using quality desiccant material.
Pro Tip: The Golden Rule of A/C Repair
Always replace the receiver drier whenever the A/C system is opened for service (e.g., replacing a compressor, condenser, or hose). The desiccant inside absorbs moisture from the air within minutes of being exposed. Failing to replace it will cause your new, expensive components to fail prematurely and will void most warranties.
Known Issues & Technical Service Bulletins (TSBs)
As of early 2026, there are no specific safety recalls for the A/C receiver drier on the 2007-2015 Audi S6. However, Audi has issued TSB 2064077/6 for insufficient cooling on some models, including the S6, which may be caused by a leaking A/C evaporator. The symptoms can be identical to a bad drier, so a professional diagnosis with a leak detector is important to avoid replacing the wrong parts.
| Part or Service | Estimated Cost |
|---|---|
| New OEM Drier (Part Only) | $60 - $165 |
| New Aftermarket Drier (Part Only) | $27.37 - $72.64 |
| Shop Labor & System Recharge | $400 - $700 |
| Total Professional Job (Aftermarket Part) | $427 - $773 |
Frequently Asked Questions (FAQ)
Can I replace the A/C receiver drier myself?
This is not recommended for DIY mechanics. The job requires specialized, expensive equipment to safely recover old refrigerant and then recharge the system with the precise amount of new refrigerant and oil. Improper handling is dangerous and illegal in many areas. This job is best left to a qualified technician.
Why must it be replaced if the system is opened?
The desiccant material inside the drier is extremely absorbent. The moment it is exposed to the atmosphere, it begins soaking up moisture from the air. It can become fully saturated and useless in a very short time. Installing a new, sealed drier is the only way to guarantee the system stays free of corrosive moisture.
My A/C has a musty smell. Is the drier bad?
It could be. A saturated drier that can no longer absorb moisture can contribute to mold growth in the system. This symptom warrants a check of the entire A/C system, including the cabin air filter and the evaporator drain tube, but a saturated drier is a likely contributor.
What's the difference between a receiver/drier and an accumulator?
They perform similar functions but are used in different types of A/C systems. Your Audi S6 uses an expansion valve system, which requires a receiver/drier on the high-pressure side. Accumulators are used on orifice tube systems and are located on the low-pressure side.
Technical Specifications
OEM Part Numbers: 4F0820191B 4F0820191A 4F0820191 8K0298403A
For 2007-2011 (C6) models, the part is a canister-style drier. For 2012-2015 (C7) models, the part is a desiccant cartridge that fits into the condenser.
We Have This Part in Stock
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 S6:
- 🛍️ Shop This Part
- Is Your S6 A/C Not As Cold As It Used To Be?
- Critical: C6 vs. C7 Generation Difference
- Symptoms of a Failing A/C Receiver Drier
- Choosing the Right Aftermarket Brand
- Tier 1: OEM-Equivalent Brands
- Tier 2: Standard Aftermarket Brands
- Pro Tip: The Golden Rule of A/C Repair
- Known Issues & Technical Service Bulletins (TSBs)
- Frequently Asked Questions (FAQ)
- 🎟️ Get 5% Off