SKU: 58796797493

034Motorsport PCV Breather Hose - Audi B9 RS4/RS5 & C8 S6/S7 2.9TT - 034-101-3109

Sale price$184.50 Regular price$205.00
Save 10%

Pay in installments of $51.25 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 18 - Jul 23

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

034Motorsport PCV Breather Hose - Audi B9 RS4/RS5 & C8 S6/S7 2.9TT - 034-101-3109034 Motorsport PCV Breather Hose Audi B9 RS4 RS5 & C8 S6 S7 2. 9TT 034 101 3109. Upgrade your failure prone PCV breather hose with the high performance, reliable 034Motorsport PCV Breather Hose, engineered for enhanced durability and long lasting performance. The 034Motorsport PCV Breather Hose isn't just an upgrade for tuned vehicles it's also a critical safety enhancement for all EA839 equipped vehicles. The PCV breather hose on the EA839 relies on

034 Motorsport - PCV Breather Hose - Audi B9 RS4/RS5 & C8 S6/S7 2.9TT - 034-101-3109.

Upgrade your failure-prone PCV breather hose with the high-performance, reliable 034Motorsport PCV Breather Hose, engineered for enhanced durability and long-lasting performance. The 034Motorsport PCV Breather Hose isn't just an upgrade for tuned vehicles - it's also a critical safety enhancement for all EA839-equipped vehicles.

The PCV breather hose on the EA839 relies on a pair of internal check valves to switch between ventilation pathways and prevent the loss of crankcase vacuum or entrance of boost pressure to the engine crankcase; however, these factory components are prone to premature failure. Once these check valves fail, they can no longer regulate crankcase pressure properly, causing the crankcase to pressurize and potentially allowing hot oil to escape that can lead to serious engine damage, including the risk of fire. This failure occurred to a development vehicle in Ashes to Asphalt, documenting the absolute worst case scenario of when the PCV system can fail. This failure can occur on bone-stock vehicles or vehicles tuned with Stage 1, 2, or 3 power levels. The 034Motorsport PCV Breather Hose is designed to offer reliable crankcase ventilation for the EA839 V6 at all power levels.

The 034Motorsport PCV Breather Hose fixes these critical safety issues, allowing the PCV system to operate flawlessly at all power levels for years to come.

Upgrade your factory corrugated plastic, failure-prone PCV breather hose with the high-performance, reliable 034Motorsport PCV Breather Hose, engineered for enhanced durability and long-lasting performance.

The PCV, or Positive Crankcase Ventilation system, on the EA839 is located on bank 2 of the engine (The right side of the engine). It is designed to ventilate the engine's positive crankcase pressure through the breather hose into the intake tract or charge air system. The breather hose plays an integral role in this ventilation system, which uses two check valves to control the flow of crankcase pressure.

How Does the PCV System Operate?

The Positive Crankcase Ventilation System on the EA839 works to remove excess pressure from the crankcase system and relies on the vacuum from the engine's intake system to operate properly. At idle or cruising while not in boost, the engine's charge air system operates under vacuum, drawing air in continuously. During this state, the PCV system utilizes this vacuum to release crankcase pressure into the charge air system through the connection just after the throttle body.

However, when the vehicle is under boost (during acceleration), this connection becomes pressurized, meaning it can no longer provide a vacuum source for crankcase ventilation. When this happens, a check valve in the breather hose closes off this connection, preventing boost pressure from entering the crankcase. At this point, the breather hose is able to draw vacuum from the turbo inlet connection, as this creates vacuum through a siphoning effect as the turbocharger draws air in through the intake.

Whether you are sitting at a stoplight or romping on a backroad, a properly operating PCV system is crucial for maintaining the engine's performance and preventing harmful pressure buildup.

Why is the OE PCV System Insufficient?

The check valves within the factory breather hose are an integral component of ensuring correct operation. However, since these check valves deal with the high temperatures of an engine bay and the transition between vacuum and boost pressure, they are susceptible to premature failure. When they fail, excess pressure can enter the crankcase, causing it to operate under conditions it was not designed for. In fact it's likely these are the same as what Audi uses on naturally aspirated engines, which makes them not up to the task of dealing with pressures associated with turbocharged engines.

As the crankcase of the engine is not designed to operate under pressure, it typically will find the path of least resistance to release this excess pressure. The seals and components inside your engine, which are designed to operate under vacuum, aren't built to handle this excess pressure. In some cases, the path of least resistance is unfortunately the oil cap, which can loosen and expel hot oil into the engine bay, potentially causing a fire.

Audi issued a TSB (Technical Service Bulletin) concerning this failure of the PCV Breather Hose as of 2020, though in our testing 034Motorsport has concluded that even the newest variant of breather hose is susceptible to failure.

Some other solutions on the market neglect the importance of maintaining adequate vacuum pressure from the charge air system and intake tract to ensure proper operation of the PCV system. Because the PCV system relies on these two separate vacuum sources under normal operation, removing one would prevent the crankcase ventilation system from functioning properly.

When these solutions remove the intake tract as a vacuum source, it disrupts the PCV system's ability to vent crankcase pressure at idle or in a cruising state while not in boost. Because the crankcase no longer has sufficient vacuum pressure, seals that are designed to operate with this vacuum pressure can fail prematurely. This lack of vacuum pressure can also lead to the potential of pressurization of the crankcase system and engine damage.

Additionally, many aftermarket solutions have check valves that do not provide sufficient flow to accommodate the boost levels of Stage 3 equipped vehicles. These check valves are too small and this inefficiency can cause restrictions, resulting in reduced flow from the crankcase, causing crankcase pressure to build up.

During the development of the 034Motorsport Stage 3 Dynamic+ tuning suite, the development B9 Audi S4 experienced an unfortunate OEM PCV breather hose failure.

This failure caused oil to be expelled through the oil cap and onto the hot turbocharger, immediately causing an engine oil fire. This failure was documented in our video Ashes to Asphalt, documenting the extent of the damage and how 034Motorsport was able to make the most out of the situation.

Because of this failure, it made engineering a proper solution that was able to withstand the harsh engine bay temperatures and elevated boost levels of utmost priority for 034Motorsport Engineers.

What is The Fix?

034Motorsport began by benchmarking the factory PCV system for flow capacity and other check valves on the market. Due to this, we opted to engineer and develop our own proprietary check valves that offer fantastic restrictionless-flow capability when open, and create a strong seal when closed, capable of holding over 40+ PSI of pressure and dealing with the high temperatures this system is subject to. These check valves utilize a durable synthetic rubber diaphragm that offers superior high heat and chemical resistance.

034Motorsport engineers designed the 034Motorsport PCV Hose to be used with the OEM Factory Air Oil Separator, as we found during testing that this unit provides excellent crankcase pressure control and is capable of supporting the flow needed at Stock through Stage 3 power levels without failure.

The 034Motorsport Check Valves are housed in a high-flow 4-ply reinforced silicone hose, specially designed to not collapse or inflate under vacuum or boost pressure. These silicone hoses are molded to allow for the factory engine cover to be utilized with the 034Motorsport PCV Breather System installed.

The 034Motorsport PCV Breather Hose uses OE-style multi-use connections, which allow for easy installation and removal when servicing your turbo inlet.

The OEM breather hose includes a new turbo inlet system as well, increasing the cost of this failure-prone component. whereas with the 034Motorsport PCV Breather System installed, there is no need for excessively costly OEM replacement components, as the 034Motorsport Breather Hose is engineered to last the lifetime of your vehicle.

The result is the 034Motorsport PCV Breather Hose, which isn't just an upgrade for performance enthusiasts€”it's a critical safety enhancement for all EA839-equipped vehicles. It has been extensively tested on several 034Motorsport development vehicles for upwards of 2 years at varying power levels to ensure its performance and reliability, whereas the OEM breather hose can fail in as little as 3 months! The 034Motorsport PCV Breather Hose is suitable for all vehicles including those that are bone stock or upgraded with Dynamic+ Stage 1, 2, or 3 tuning!

Features:

  • Direct Replacement of the Failure Prone OE PCV Hose
  • Ensures High Flow Crankcase Ventilation to Prevent Crankcase Pressurization
  • Eliminates Potential Boost Leak at OE Plastic Check Valve Housing
  • Supports Boost Pressures to 40+ PSI
  • Compatible with OEM and Upgraded Turbocharger Inlets
  • CNC-Machined, Billet Aluminium Check Valve Body (Black Anodized), with a Heat and Chemical Resistant, Durable Rubber Diaphragm
  • 4-Ply, Reinforced, Silicone Hose
  • Retains Factory Engine Cover
  • Simple Installation

Fitment:

* 034-101-3109 is for B9/C8 2.9TT engines such B9 RS4/RS5 and C8 S6/S7.

Make Model Years Chassis Engine Note
Audi A6 2019-Present C8 3.0 TFSI Select: B9/B9.5/C8 3.0T Engines
Audi A7 2019-Present C8 3.0 TFSI Select: B9/B9.5/C8 3.0T Engines
Audi allroad 2019-Present C8 3.0 TFSI Select: B9/B9.5/C8 3.0T Engines
Audi S4 2018-Present B9/B9.5 3.0 TFSI Select: B9/B9.5/C8 3.0T Engines
Audi S5 2018-Present B9/B9.5 3.0 TFSI Select: B9/B9.5/C8 3.0T Engines
Audi SQ5 2018-Present B9/B9.5 3.0 TFSI Select: B9/B9.5/C8 3.0T Engines
Audi S6 2019-Present C8 2.9 TFSI Select: B9/B9.5/C8 2.9T Engines    
Audi S7 2019-Present C8 2.9 TFSI Select: B9/B9.5/C8 2.9T Engines    
Audi RS4 2018-Present B9/B9.5 2.9 TFSI Select: B9/B9.5/C8 2.9T Engines    
Audi RS5 2018-Present B9/B9.5 2.9 TFSI Select: B9/B9.5/C8 2.9T Engines    


Recommended product: 
Audi B9 RS4/RS5 ECU tuning

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 58796797493

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.0 ★★★★★
Based on 17 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
T
Verified Purchase
TB52
Bozeman, US
★★★★★ 3
Charming and Summery, But Longer Than It Should Be
Format: Paperback
⭐️⭐️⭐️💫 (3.5 Stars) I listened to Every Summer After on audio, and at first, it really felt like it had the potential to be a solid 4-star read for me. The beginning is charming, easy to sink into, and definitely has that cozy, nostalgic summer atmosphere that so many readers love. It’s a cute, pleasant story with a smooth flow, and the type of book you can listen to without needing to focus too deeply. However, as the story went on, the pacing became a real issue. At around ten hours, this audiobook felt unnecessarily long. The plot didn’t have enough depth or twists to justify that length, and I honestly think it would have been a much stronger book if it wrapped up closer to the seven-hour mark. Around the midpoint, I found myself losing interest at times simply because the narrative stretched itself thin. When it comes to the writing itself, Carley Fortune keeps things very simple. There’s nothing particularly inspiring, profound, or memorable about the prose. It’s straightforward and easy to follow, but it doesn’t stand out, and I wouldn’t say it’s developed enough to be considered a distinct “writing style.” It does the job, but it never elevates the story or adds emotional depth the way some authors can. I also didn’t fall deeply in love with the characters. They were fine, but not the type that stay with you after the book is over. Because the character connection never fully clicked for me, the slower pacing felt even more noticeable, and some of the emotional beats didn’t land as strongly as they were intended to. Overall, Every Summer After is an easy, pleasant listen — perfect if you’re looking for something light, summery, and uncomplicated. While the overly long runtime, very simple writing, and limited emotional connection kept it at 3.5 stars for me, it’s still a sweet story that delivers exactly what many readers look for in a nostalgic summer romance. I’m still open to exploring more of Carley Fortune’s books, and I’m curious to see how her other stories compare!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 12, 2025
J
Verified Purchase
joycelyn
Houston, US
★★★★★ 5
a perfect summer romance
Format: Paperback
this book was phenomenal!! i loved every page and i fell in love with the story and characters. it’s told in past and present timelines over the course of six summers and one weekend 12 years later. you get small town, second chance romance, childhood best friends to lovers to strangers to lovers, and more! some of my fav tropes in one book <3 i love the parallel events between the past and present chapters, seeing how percy and sam grown and matured but also stay the same throughout the years (iykyk - the friendship bracelets, “swear on it”, ice cream). their attraction and connection are undeniable! the book perfectly captures friendship, teenage angst, first love, loss, mistakes, and forgiveness. it’s also about finding your person, someone who understands you like no other. the writing was spectacular - it was so magical and enchanting as it encapsulated summer nostalgia at a lakeside cottage. i felt like i experienced every summer with percy and sam. i love how real and relatable the characters are. percy and sam are two flawed characters that let their fears get in their way, but they try their best to repair what they broke. i adore sam so so much, he’s the sweetest and kindest guy who loves really hard. the sarcasm and banter between the two were soo good too, i loved how we get a glimpse of what they were like at 13 and then at 30. this is the PERFECT summer read, i highly recommend it!! i promise you’ll love this if you love ‘love and other words’ by christina lauren! i didn’t think i’d find a book like laow that hits the same, but reading this book made my lil laow heart so happy 💞 i’m blown away by the fact that this is carley fortune’s debut novel and i hope there is more to come!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 16, 2023
B
Verified Purchase
Bartika
Louisville, US
★★★★★ 5
A book that hugs back.
Format: Hardcover, Format: Hardcover
I picked this book for my brother-in-law when we were celebrating my sister’s pregnancy, and the title ‘Why a daughter needs a dad’ sealed the deal. The illustrations are beautiful and full of tenderness. The messages on each page are simple and meaningful. I could so clearly picture him reading it to his baby girl someday. It’s the kind of book that isn’t just read – it’s felt. A thoughtful gift for someone you love – especially during such a special season of life.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 13, 2026
C
Verified Purchase
Cameron Hutcheson
Los Angeles, US
★★★★★ 5
Great book, well written!
Format: Hardcover
I love reading this with my daughter, we have so much fun and the book is great! Fun pictures, fun ideas and very entertaining.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 30, 2026
T
Verified Purchase
Teresa Safford
Charlottesville, US
★★★★★ 5
The most beautiful and touching book!!!
Format: Hardcover
One of the most touching gifts you could give from your little girl to her daddy! Cried when I read it! The illustrations are beautiful and the story is so touching!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 18, 2025

recommand products