Audi A6 Engine Crankcase Breather Hose Guide (2011-2015)
Addressing the common whistling noises, oil leaks, and check engine lights on your C7 Audi A6.
- A loud whistling noise from the engine at idle is a tell-tale sign of a failed breather hose or PCV valve.
- Before purchasing parts, call an Audi dealer with your VIN to check for the 10-year/120k-mile extended warranty (U38) on the PCV valve.
- For the 3.0T engine, the repair is extremely labor-intensive; always use a high-quality part to avoid repeating the job.
- The repair is simple on the 2.0T engine but very difficult and expensive on the 3.0T engine due to part location.
Is Your Audi A6 Making a Whistling Noise?
A failing crankcase breather hose or PCV valve is one of the most common issues on the 2011-2015 Audi A6. These parts are made of plastic and rubber that can become brittle and crack over time, leading to vacuum leaks and other problems. Symptoms often start subtly but can become more serious if ignored.
Common Failure Symptoms
- Whistling or Hissing Noise: A high-pitched whistle, hiss, or sucking sound from the engine bay at idle is a classic sign of a failed PCV diaphragm or a cracked hose. This is often the first symptom owners notice. 🎬 Watch: Hear what a failing PCV whistling noise sounds like.
- Check Engine Light: The failure will disrupt the engine's air-fuel mixture, triggering a check engine light with codes for a lean condition (P0171), intake system leak (P227900), or a specific PCV valve performance issue (P052E00).
- Rough Idle: The engine may idle erratically, surge, or even stall because of the unmetered air entering through the leak.
- Increased Oil Consumption: A faulty valve can suck excessive oil vapor into the combustion chamber, causing your engine to burn oil. You might notice blue smoke from the exhaust.
- Oil Leaks: When the system is clogged, pressure builds inside the crankcase and can force oil out of gaskets and seals, leading to new or worsening oil leaks.
Known Issues for 2011-2015 Audi A6
Audi has acknowledged issues with the PCV system on these vehicles. A Technical Service Bulletin (TSB 2060259/1) notes that an elbow piece on the breather assembly can crack on 3.0T engines. More importantly, Audi issued a Crankcase Ventilation Valve Extended Warranty (U38) for some 2013-2016 models with the 3.0L engine, extending coverage to 10 years or 120,000 miles. Before buying a part, contact an Audi dealer with your VIN to see if your vehicle is covered under this warranty extension.
Choosing the Right Aftermarket Part: 2.0T vs. 3.0T Engines
The engine in your A6 dramatically changes this repair. The 2.0T engine's PCV and breather hose assembly is on top of the engine and is relatively easy to access. However, on the 3.0T supercharged engine, the entire assembly is buried underneath the supercharger.
For 3.0T Supercharged Engines: The labor to replace this part is very expensive (5-8+ hours), as the supercharger must be removed. Because of the high labor cost, using a budget-friendly part is a major risk. If a cheap part fails, you will pay for the same expensive repair twice. It is strongly recommended to use an OEM-quality part.
For 2.0T Turbocharged Engines: Since the part is easy to access and replace (1-2 hours), an aftermarket part is a more reasonable choice. You can save money without risking a huge labor bill if the part fails prematurely.
Aftermarket Brand Quality
- Gates: Gates is a well-known manufacturer of hoses and rubber products with a reputation for quality. They are generally considered a reliable aftermarket choice.
- Vaico: Vaico offers parts that can be a decent value, but quality can be inconsistent. Some users report success, while others advise caution. It may be a suitable option for the easily accessible 2.0T part.
- URO Parts: URO is typically a budget-focused brand. While the price is low, these parts have a higher risk of poor fitment or early failure. This brand should be avoided for the 3.0T engine due to the difficult installation.
Pro Tip: The plastic connectors on these breather hoses are very brittle and often break during removal, even with care. It's wise to plan on replacing any hose you need to disconnect during the repair.
Cost to Replace an Audi A6 Crankcase Breather Hose
| Part/Service | 2.0T Engine Cost | 3.0T Engine Cost |
|---|---|---|
| New Aftermarket Part | $50 - $150 | $100 - $220 |
| Shop Labor | $150 - $300 | $900 - $2,000+ |
| Estimated Total | $200 - $450 | $1,000 - $2,220+ |
Cost estimates are for reference only and will vary based on location, the specific parts needed, and the repair shop.
Frequently Asked Questions
Can I still drive my A6 with a bad breather hose?
You can drive for a short time, but it is not recommended. A vacuum leak will cause poor engine performance and fuel economy. A clogged system can lead to blown seals and expensive oil leaks. It is best to get it repaired promptly.
Is this a DIY job?
For the 2.0T engine, yes. An experienced DIY mechanic can replace the top-mounted PCV assembly in 1-2 hours. For the 3.0T engine, this is a very advanced and difficult job that requires removing the supercharger and dealing with fuel lines and coolant. It is not recommended for beginners.
🎬 See this step-by-step guide for replacing the 2.0T PCV valve.Why is the repair so expensive for the 3.0T engine?
The entire PCV system, including the breather hoses, is located in the engine valley, underneath the supercharger. To access it, a technician must spend several hours removing the supercharger, fuel rails, and other components. The high cost is almost entirely due to this extensive labor.
🎬 Watch: Essential tips and tricks for the 3.0T supercharger removal.How do I check for the Audi PCV warranty extension?
Call any authorized Audi dealership service department and provide them with your vehicle's 17-digit VIN. They can look up your vehicle and tell you if the U38 warranty extension for the crankcase ventilation valve is active for your car.
Helpful Videos
Technical Specifications
OEM Part Numbers: 06E103207AP 06E103213 06E103547AE 06E103547T 06E103547AK
Component of the Positive Crankcase Ventilation (PCV) system. Typically made of plastic and rubber. Connects the PCV/oil separator to the intake system. Different designs are used for the 2.0T and 3.0T engines.
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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 A6:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Audi A6 Making a Whistling Noise?
- Common Failure Symptoms
- Known Issues for 2011-2015 Audi A6
- Choosing the Right Aftermarket Part: 2.0T vs. 3.0T Engines
- Aftermarket Brand Quality
- Cost to Replace an Audi A6 Crankcase Breather Hose
- Frequently Asked Questions
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