Emissions System

On M52/S52-equipped BMWs, the factory crankcase ventilation (CCV) system is a notorious weak link. Between brittle plastic corrugated hoses that crumble from heat soak and an internal cyclone diaphragm prone to tearing, a failing CCV leads to massive oil consumption, vacuum leaks, and that dreaded "howling" whistle.

This kit addresses these issues with all new components and hardware. Both oil separator hoses, the cyclone separator itself, the mounting grommet, and the retaining bolts are included. Servicing this system is guaranteed to restore performance lost as a result of worn CCV components.

Kit includes:

Cyclone Separator/Crankcase Pressure Regulator Valve High Performance Silicone Breather Hose Return Hose Mounting Grommet Hex Bolt (3)

Restore proper engine ventilation with this premium replacement Crankcase Breather Valve (11127809512).

Designed to match the performance of the original BMW unit (OE 11-12-7-809-512 / 11-12-7-803-790), this valve maintains correct crankcase pressure, helps prevent oil buildup, and supports clean, efficient engine operation.

Crafted from high-quality, long-lasting materials and shaped to replicate the factory design, it installs easily in place of the stock breather without any modifications required.

Whether you’re addressing pressure-related drivability issues, refreshing your engine’s ventilation system, or performing preventative maintenance, this breather valve provides dependable performance and protects your BMW’s engine for the long haul.

Oil venting and circulation continues to be a problem on BMW engines and now even more so on the turbocharged N54 and N55 engines. The existing stock system does a very poor job of separating fluid and vapor and this leads to an oily film or even small pools of oil throughout the turbos and intake. We're seeing a lot more 135 and 335 cars with drivability and performance issues because oil has sneaked by the ring seals and is coating the intake piping, intercooler, intake valves, and other critical areas. The problem is worsened with higher boost levels. Oil is excellent for lubricating moving parts but terrible when it gets into the combustion chamber, effectively lowering the octane rating and reducing performance. Our own shop has gone the extra step and offers media blasting of the intake valves to strip away the oily buildup we have seen.

Our shop also strongly recommends an oil catch can be installed in the line for the crankcase vent. The oil catch can traps oil as it leaves the valve cover and holds it in a canister. Whatever minimal vapors are left over in the oil is then vented back through the canister and into the intake where it is safe to be burned up in the engine or recirculated back through the system again. This is the way the system was designed! At each oil change simply unscrew the canister and empty the trapped oil with your regular used oil. A dipstick is integrated into the cap so you can monitor the oil level. Installing one of these will avoid costly repairs in the future and help maintain your boost and performance. It's one of the smartest modifications you can make because it demonstrates a well-thought out tuning strategy and care for the condition of your engine.

The ECS Oil Catch Can is made from aluminum and with a stealthy black anodized finish. Multiple brackets are available so you're not limited on where to mount it. The location is key as heat will evaporate the oil and send too much vapor back into the engine (where cooler air will turn it back into fluid). The ECS OCC also has a factory-like appearance.

Note: Since the crankcase vent system is considered part of the overall emissions system, installing this may be a violation of local, state, and federal laws. While exemptions are made for track/race and off-road use, check with your local state inspection facility on using this in street-driven vehicles.

ECS Oil Catch Can Features:
+ Increases air intake efficiency
+ Promotes engine longevity
+ 4 chamber design promotes excellent air/oil separation
+ Large In/Out ports (no tapered sizes that slow flow)
+ Anodized black lightweight aluminum
+ Made in USA

This item fits the following BMWs with the N54 twin-turbo engine:
2008-2010 E82 BMW 135i
2007-2010 E9X BMW 335i 335xi
2006-2010 E60 BMW 535i 535xi

Modern day emissions regulations require the use of a closed crankcase ventilation (PCV) system to recirculate combustion blow-by gases from the crankcase back in to the intake to be burned.  Unfortunately, these blow by gases contain water vapor (which is a byproduct of combustion) and pick up oil mist from and the windage cloud and cam lubrication system as they travel through the crank case.  Due to less than 100% effective air/oil separation in the stock PCV system, some oil mist and water vapor gets carried back to the intake tract and over time cause oil deposits in the intake manifold, intake ports, and on the back of intake valves.  All will eventually lead to poor performance and reduced fuel economy, and the presence of this oil mist in the intake charge may even increase the risk of engine-damaging detonation. 

With forced induction, track use, and/or extended high RPM usage, these symptoms increase as the factory PCV system is overwhelmed, and a catch can becomes a must for your E46 M3. This kit is a direct fit making this an easy reversal if desired as well as maintaining a clean appearance by utilizing the open "smuggler's compartment" on the passenger side of the engine bay.

ECS engineers developed a catch can that utilizes a strategically designed 4 chamber baffle plate system engineered to create multiple changes in the direction of airflow to cause oil droplets to fall out of suspension, maximizing the efficiency of the PCV air/oil separation.  A dipstick is integrated into the cap so you can monitor the oil level, and the can is easily serviced.  At each oil change simply unscrew the canister and empty the trapped oil with your regular used oil.  The ECS Oil Catch Can is CNC machined from billet 6061-T6 aluminum and with a stealthy black anodized finish for lasting durability and appearance, and includes everything needed for an OEM-like fully reversible installation.  

The ECS Oil Catch Can is made from aluminum and with a stealthy black anodized finish. The location is key as heat will evaporate the oil and send too much vapor back into the engine (where cooler air will turn it back into fluid). The ECS OCC also has a factory-like appearance. Having a kit designed specifically for your E46 M3 makes for a clean looking setup that any skill level mechanic can install. 

Note: Since the crankcase vent system is considered part of the overall emissions system, installing this may be a violation of local, state, and federal laws. While exemptions are made for track/race and off-road use, check with your local state inspection facility on using this in street-driven vehicles.

*Click here for installation instructions*

ECS Oil Catch Can Features:
+ Increases air intake efficiency
+ Promotes engine longevity
+ 4 chamber design promotes excellent air/oil separation
+ Large In/Out ports (no tapered sizes that slow flow)
+ Anodized black lightweight aluminum
+ Made in USA

This item fits the following BMWs
E46 M3 2001-2006

This is the BMW crankcase return line that goes from the intake manifold to the top CCV connecting hose. We also offer a complete CCV repair kit
Since the late 1800’s Febi has been fabricating replacement metal parts. This history is self evident in the quality and vast amount of applications they service. With more than 34,000 repair solutions for cars and commercial vehicles you can be sure Febi has you covered.

This item fits the following BMWs:
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi
1997-2003 E39 BMW 525i 528i 530i
2004-2010 E60 BMW 525i 530i
2004-2005 E83 BMW X3 2.5i X3 3.0i X3 3.0si
2000-2006 E53 BMW X5 3.0i
1/2000-2002 Z3 BMW Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i
2003-2005 E85 BMW Z4 2.5i Z4 3.0i