034 Catch Can Kit For B9 Audi RS4/RS5 2.9T EA839

Upgrade your failure-prone PCV breather hose with the high-performance, 034Motorsport Catch Can Kit, engineered for enhanced durability to capture crankcase oil deposits before entering your intake tract.

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 a breather hose into the intake tract or charge air system. The 034Motorsport Catch Can was engineered to improve upon the factory PCV system, implementing a baffled Billet Aluminum Catch Can to trap crankcase oil deposits before entering your intake tract. The Catch Can Kit utilizes a re-engineered breather hose that plays an integral role in this ventilation system.

How Does the PCV System Operate? The Positive Crankcase Ventilation System, or PCV for short, works to remove excess pressure from the crankcase system and relies on vacuum from the engine’s intake system to operate properly. This system operates with two components, an Air Oil Separator and a Breather Hose.

In the EA839, crankcase pressure is generated by the engine rotating assembly moving under normal operation, and can contain oil in the form of liquid & vapor, water vapor from condensation, and blow-by gases. The Air Oil Separator acts as a collection chamber for this crankcase pressure and oil, separating some, but not all of the oil and water vapor, allowing the oil to drain back into the engine oil pan. The crankcase pressure not caught in this chamber is evacuated through the breather hose to be ingested by the engine.

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 breather hose 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 upper intake manifold 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 to replace the flawed breather hose design. 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.

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

The Billet Aluminum Catch Can is engineered to fit in line with the factory Air Oil Separator and 034Motorsport’s re-engineered breather hose to capture crankcase oil deposits. The 034Motorsport Catch Can Kit allows the full PCV system to properly vent crankcase pressure while keeping oil vapor and liquid oil out of the intake tract, resulting in drastically reduced carbon buildup and extended life from the EA839. The Catch Can Body was meticulously designed to ensure it collects liquid oil and oil vapors through its baffle plate, while still allowing effective flow to vent crankcase pressure through the intake tract as designed.

This offers increased reliability of the crankcase ventilation on the EA839 V6 at all power levels and an additional layer of protection over the standard 034Motorsport Breather Hose replacement.

034Motorsport engineers designed the 034Motorsport Catch Can Kit to be used with the OEM Factory Air Oil Separator rather than design a bespoke 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.

For added convenience, there is an integrated dipstick allowing for a quick and easy way of checking levels. The Catch Can also includes an integrated drain line that allows for service-free use of the 034Motorsport Catch Can, draining the captured oil back to the oil pan.

The 034Motorsport Catch Can Kit uses OE-style multi-use connections, which allow for easy installation and removal when servicing your turbo inlet or catch can.

The 034Motorsport Catch Can Kit 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 Catch Can is suitable for all vehicles including those that are bone stock or upgraded with Dynamic+ Stage 1, 2, or 3 tuning!

Why Do You Want a Catch Can?

The Air Oil Separator acts as a collection chamber, capturing some of the oil and water vapor present in the crankcase while regulating pressure. Any uncollected vapors are expelled through the breather hose, and the oil captured in the air oil separator is drained back into the oil pan.

As this crankcase pressure is evacuated through the breather hose and into engine’s intake tract, the uncollected vapors pass through and enter the intake system. This can cause oil to pool within the intake tract, generate carbon buildup on intake valves, or be ingested by the engine resulting in dirty combustion.

The 034Motorsport Catch Can intercepts this uncollected oil vapor with an intricate baffle that allows the 034Motorsport Breather Hose to continue venting the crankcase pressure and water vapor into the intake tract to be ingested by the engine. Once collected by the 034Motorsport Catch Can, this oil vapor pools within its large body. This decreases oil in your intake tract, reduces carbon buildup on intake valves, and results in an overall cleaner combustion process.

As the catch can system is under 212*F, it allows small amounts water vapor to condensate and mix with the oil, resulting in a milky texture. This mixture is then drained through the integrated drain line back into the oil pan, allowing the water vapor to pass through the PCV system uninterrupted and be burned off in the combustion cycle.

Within the operation of the complex PCV system, this water vapor is intended to be burnt off during the combustion process. This small amount of water that is collected in the catch can drains back into the oil pan, re-vaporizes, and re-enters the PCV system to be burnt off without causing any issues.

Features:

• Direct Replacement of the Failure Prone OE PCV Hose
• Ensures High Flow Crankcase Ventilation to Prevent Crankcase Pressurization
• Unlike Other Kits, Our Solution is the Only One on the Market That Can Hold The Pressures and Flow Enough to Ensure Proper PCV and Turbocharger System Performance
• Supports Boost Pressures to 40+ PSI
• Compatible with OEM and Upgraded Turbocharger Inlets
• Eliminates Potential Boost Leak at OE Plastic Check Valve Housing
• CNC-Machined, Billet Aluminum Check Valve Body (Black Anodized), with a Heat and Chemical Resistant, Durable Rubber Diaphragm
• Large Diameter, 4-Ply, Reinforced, Silicone Hoses
• OE hose diameter: ~16mm
• 034 hose diameter: 22.5mm
• Prevents Crankcase Oil Deposits in Intake Manifold and on Intake Valves
• Reduces Carbon Buildup
• Integrated Dipstick for Easy Level Checks
• Retains Factory Engine Cover
• Service-Free Use with Included Catch Can Oil Drain!
• Simple Bolt-In Installation

 

Part Number Interface:

• 06M 129 041 (3.0T)
• 06M 129 041 F (2.9T)
   

What's Included:

• 034Motorsport Valve Cover Breather Fittings (Black Anodized)
• 034Motorsport Catch Can Assembly (Black Anodized)
• 2x) 034Motorsport Breather Check Valves
• 1x) 034Motorsport Reinforced Silicone Hose
• Catch Can Oil Drain Kit
• No-Drill Mounting Bracket
• Installation Hardware