Audi A6 (C6) Engine Crankcase Breather Hose: A Guide for 2006-2010 Models
If you're hearing a hissing sound or experiencing a rough idle, your A6's crankcase breather hose may be the culprit.
- The original plastic breather hose on the 3.2L V6 is known to become brittle and crack, causing vacuum leaks.
- Symptoms often include a loud hissing noise, a rough idle, and a Check Engine Light.
- A quality aftermarket brand like Gates offers a more durable and cost-effective solution compared to the expensive OEM part.
- Audi used two different hose designs in 2006; you must verify the correct part for your VIN.
Is Your Audi A6 Breather Hose Failing?
The original crankcase breather hoses on the 2006-2010 Audi A6, particularly on the 3.2L V6 engine, are known to fail with age. The factory-installed hoses are made of a hard plastic that becomes brittle over time due to constant exposure to engine heat. Eventually, they crack or even break apart completely. This failure creates a vacuum leak, allowing unmetered air into the engine, which can cause a variety of noticeable problems.
Symptoms of a Cracked Breather Hose
- Loud Hissing or Sucking Noise: This is one of the most common signs. A distinct hissing sound from the engine bay at idle points to air being sucked through a crack in the hose.
- Rough Idle: The engine may run poorly or shake at idle because the vacuum leak disrupts the carefully balanced air-to-fuel ratio.
- Check Engine Light: A vacuum leak will often trigger the Check Engine Light. You may see fault codes related to a lean air/fuel mixture (like P0171), an intake air system leak (P2279), or the idle being higher than expected (P0507).
- Oil Leaks: While a cracked hose causes a vacuum leak, a clogged breather system can cause the opposite problem. Blockages from oil sludge increase pressure inside the engine, which can force oil out of gaskets and seals.
Check Your VIN for the Correct Part
Audi changed the design of the PCV and breather hose system midway through the 2006 model year. Early models have a different hose assembly than later models. Always verify the correct part number for your specific vehicle using your VIN to avoid ordering the wrong part.
Choosing the Right Aftermarket Part: OEM vs. Gates
When replacing this part, you have a choice between an original Audi part (OEM) and an aftermarket one. Given the known issues with the original's material, a quality aftermarket part is often a smarter choice.
- OEM (Original Equipment Manufacturer): An OEM hose will be a direct fit, but it is made from the same brittle plastic that likely failed in the first place. It is also significantly more expensive.
- Gates (Aftermarket): Gates is a well-regarded brand that manufactures aftermarket hoses designed to be direct replacements. These hoses are made from modern materials that are resistant to oil, fuel vapors, and high temperatures, offering a more durable solution than the original design. For this specific part, an aftermarket hose from a reputable brand like Gates provides better value and potentially a longer service life.
Pro Tip: Inspect While You're There
The breather hose is often handled or removed when performing other maintenance, like changing spark plugs or valve cover gaskets. Because the old hose is so brittle, it frequently breaks during these jobs. If you are working in this area, it's wise to inspect the hose carefully and consider replacing it proactively to avoid having it fail unexpectedly.
Cost of Replacing the Engine Crankcase Breather Hose
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Gates) | $24.54 |
| New OEM | $200 - $275 |
| Shop Labor | $120 - $360 |
Frequently Asked Questions
Can I replace the breather hose myself?
Yes, this is a job that a DIYer can handle. It typically takes about one to two hours. The main difficulty is the brittle nature of the old plastic connectors, which can break easily upon removal. Access can also be tight, as the hose may run under the throttle body. Taking your time and being gentle is key.
What happens if I don't replace a broken breather hose?
Driving with a broken breather hose will cause a persistent rough idle, poor engine performance, and bad fuel economy. The constant vacuum leak can also put stress on other components over time. If the system is clogged instead of cracked, the resulting pressure buildup can cause multiple engine oil leaks.
Is there a recall for this part on my Audi A6?
No, there are no official recalls from the NHTSA for the engine crankcase breather hose on the 2006-2010 Audi A6. Recalls for this vehicle generation typically concern airbags or other systems.
Why are there different part numbers for the same year?
Audi updated the PCV system during the 2006 model year. This means an early 2006 A6 may have a different breather hose assembly than one built later in the year. It is critical to confirm the correct part for your car's VIN before purchasing.
Technical Specifications
OEM Part Numbers: 06E103217M 06E103217H 06E103217L
The breather hose assembly connects the valve covers to the PCV valve (oil separator). It is typically a multi-piece hose made of molded plastic. There are at least two major design variations depending on the vehicle's production date.
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: