Emissions System

Rubber breather pipes in various BMW applications are susceptible to cracking. Over time, engine heat and weather conditions can weaken these hoses, leading to breaks or leaks. This results in significant vacuum leaks that can severely affect engine performance.

Moreover, BMW faces a problem with oil separators freezing in cold weather, particularly if the engine isn't adequately warmed up during driving. Typical signs include a howling noise and subsequent oil leaks.

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. This catch can is located on the cooler side of the engine where the oil will condense easier and stay in the can. 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. The Burger Tuning oil catch can is the best we have seen so far. 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 BMS Oil Catch Can is made from aluminum and with a stealthy black anodized finish. It installs on the cooler side of the engine with a dedicated bracket and new oversized vent lines. 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 BMS OCC also has a factory-like appearance. Since BMS designed their catch can from scratch they can guarantee it fits and performs correctly for the N54/N55 engine, unlike other catch cans on the market that are poorly retrofitted from other applications and under-sized for the N54 engine.

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

BMS Oil Catch Can Features:
+ Increases air intake efficiency
+ Promotes engine longevity
+ Double-baffled design allows excellent air/oil separation
+ Large In/Out ports (no tapered sizes that slow flow)
+ Stealth mounting on cooler side of engine bay (promotes condensation of oil to vapor)
+ Anodized black lightweight aluminum
+ N54 version mounts out of sight under the cowl
+ Made in USA with a lifetime guarantee

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. This catch can is located on the cooler side of the engine where the oil will condense easier and stay in the can. 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. The Burger Tuning oil catch can is the best we have seen so far. 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 BMS Oil Catch Can is made from aluminum and with a stealthy black anodized finish. It installs on the cooler side of the engine with a dedicated bracket and new oversized vent lines. 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 BMS OCC also has a factory-like appearance. Since BMS designed their catch can from scratch they can guarantee it fits and performs correctly for the N54/N55 engine, unlike other catch cans on the market that are poorly retrofitted from other applications and under-sized for the N54 engine.

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

BMS Oil Catch Can Features:
+ Increases air intake efficiency
+ Promotes engine longevity
+ Double-baffled design allows excellent air/oil separation
+ Large In/Out ports (no tapered sizes that slow flow)
+ Stealth mounting on cooler side of engine bay (promotes condensation of oil to vapor)
+ Anodized black lightweight aluminum
+ N54 version mounts out of sight under the cowl
+ Made in USA with a lifetime guarantee

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 535xiThis 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

Due to weak rubber construction and exposure to heat, this vacuum hose may be brittle and/or broken.

Replace it with this high-quality piece from Bremmen Parts to ensure proper turbocharger functionality.