SKU: 7375987926

034Motorsport PCV Breather Hose - Audi / EA839 / 2.9T / 3.0T

Sale price$161.35 Regular price$179.28
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Description

034Motorsport PCV Breather Hose - Audi / EA839 / 2.9T / 3.0TUpgrade 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

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. br*2 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 Aluminum 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

EMISSIONS DISCLAIMER:

  • This product is sold for racing use as well as use on vehicles not registered for on highway use.
  • By purchasing this product, you understand that this product is sold for racing use as well as used on vehicles not registered for on highway use, and that it is not legal for use on highway or street vehicles.
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: 7375987926

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4.9 ★★★★★
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Link
Fort Morgan, US
★★★★★ 5
Quality
Color: Black
This is by far the best frother I've used. Battery life is great. Its UX is excellent. Feels nice in the hand and has great power. Also like the on/off button as opposed to haveing to hold a switch down. Looking forward to getting their s3 scale.
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Reviewed in the United States on April 11, 2026
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Verified Purchase
Sonya the vet
Cuba, US
★★★★★ 4
Overall good frother
Color: Black
Bought the Maestri and the Zulay frother to test which one is better since both had good reviews. Returned the Zulay (see Zulay review) and kept the Maestri. Been using it for a few days now and works well. Mixes chai and hot chocolate well. It has one speed that is a good speed to mix, but not so fast that it causes the drink to spill over the top as long as the cup is filled to about 80% full. Because I tend to use the tall 20 oz Contigo autoseal cups, it could benefit from offering longer attachments to reach the bottom of the cup (note: that I did not find any company that offers longer attachment arms).
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Reviewed in the United States on January 28, 2026
S
Verified Purchase
SantaBGirl
Birmingham, US
★★★★★ 5
LOVE this frother and the creamy results!
Color: Black
I LOVE this gadget! And I'm not a gadget person. Since I got it a few days ago, I've switched from using my Nespresso coffee maker, which uses pods and which I really like, to using Starbucks instant coffee packets (cheaper and more environmentally friendly than pods). I put a packet of the coffee and two packets of Equal in a cup, add half and half, then use this frother to mix them. Within a few seconds -- no more than 5, if that -- I have a thick mound of creamy froth. Then I had the water to finish making the coffee. Fantastic. This thing is so easy and fun to use. This is not the cheapest frother available. I wanted a rechargeable unit that has sufficient power to make nice, creamy froth. Also, I didn't want to spend $10 and have the thing break and have to replace it. Reviews suggest the cheaper ones are fine if you don't regularly use a frother. I never used one before and didn't really think I would use it very often. But I like it so much, I've been using it twice a day. Also, I first saw one in use while traveling in India. Another guest at my small hotel had one, which she used to make a latte with rather than drink the rather tepid offering at the more tea-oriented hotel. That's when I decided to get one. I'll be taking it on future trips. Some come with travel containers; this one didn't. The only learning curve was making sure the cup or pitcher for the cream is deap enough not to splash out the cream. I think I'm actually using a little less cream than I used to because the volume increases so much. I use cold cream, not heated (I used to heat it in the microwave when I was using the NesPresso.) I find I like the initial contrast with the cold cream at the top, then I stir it down into the coffee. The Starbucks coffee is excellent. I've used it for iced lattes in the past, so I knew it was good. I can hardly wait for a heat wave to make them with this frother. I did try to beater attachment in eggs when I was making an omelet. Not worth the trouble -- first, the bowl I was using to beat the eggs was too shallow and egg got all over. Second, a fork works just as well. If I were whipping cream, I would definitely use it.
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Reviewed in the United States on March 7, 2026
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Verified Purchase
Amanda Gilmore
Phoenix, US
★★★★★ 5
Best frother ever
Color: White
This brother is wickedly powerful you don't need to use it for very long to get phenomenal frothing results Incorporates ingredients quickly
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Reviewed in the United States on April 16, 2026
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Verified Purchase
GoGreen
Lake Worth, US
★★★★★ 5
Works great and so much fun!
Color: Black
How did I live without this for so long? I love this little gadget! It gets used multiple times a day. It's not only great for frothing milk but it will whip eggs for a recipe and stir other ingredients as well. People who have complained that the stirring attachment was missing a piece did not read the description. The picture clearly shows there is no "boot" on that attachment, you don't want that one to spin like the frother. The Frother holds a charge for quite a while as well. I use mine multiple times a day and it is still holding a charge after weeks of daily use. Great item!
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Reviewed in the United States on February 15, 2026

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