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Oil Separation & Breather System

Oil Separation & Breather System

Every car has a crankcase vent system that is supposed to suppress oil from making it into the intake ports and combustion chamber. A good functioning system will separate oil from the atmosphere and return it to the oil pan (or collect it in a catch can) while allowing the leftover vapors to burn in the combustion chamber or recirculate through the system. This has always been known as a PCV system (Positive Crankcase Ventilation) but BMW has several other names for it - oil separator, crankcase vent (CCV), and cyclonic separator. Failures in the system will allow raw oil to enter the intake and eventually into the engine itself which can have disastrous effects on engine performance and longevity. As emissions regulations on oil and gas venting have gotten more stringent the PCV systems have gotten more complex and failure prone. And because the CCV is intertwined with other systems you could experience rough running, loss of power, higher oil consumption, misfiring, stalling, or other annoying issues. There is no replacement interval for these so we recommend inspecting your crankcase vent system as part of your regular maintenance routines. Symptoms of a bad crankcase vent are: whitish or yellowish film on the underside of the oil cap, whistling/squealing noises (not caused by a belt), suction on the oil cap that makes it hard to unscrew, large amounts of white smoke from the exhaust, and excessive oil consumption.

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CCV/PCV Breather Hoses (6)

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E82 135i N54, E9X 335 N54, E60 535 Vargas Upgraded PCV Valve ...

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T#:389684

Part#: VTT-N54-PCV

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$ 68.99 USD

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The crankcase oil vent system on the N52/N54 is one of its weakest and cheaply designed systems. We see crankcase vent issues on even stock engines but with more boost the problems are exponential. This Vargas upgraded PCV valve, and an oil catch can, are what the N54 engine needs and may alleviate most of your oil and boost leak issues. The PCV valve is supposed to let oil either return to the oil pan or pass through the intake manifold and get burned up in the combustion chamber. However, BMW used a weak plastic vent valve that doesn't seal well when under boost. Instead of closing and venting the oil out of the intake, it's forced through this valve and into the intake and coating your valves with oil residue and carbon. Most boost equals more oil forcing its way by. This upgraded N54 PCV valve uses higher grade materials, including aluminum, to provide a better seal and prevent oil from entering the intake. It's an easy install and a must-have item when considering any turbo work.

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VTT Gen-1 PCV CAP - B58

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T#:4813265

Part#: VTT-B58-PCV-CAP

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$ 149.99 USD

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Vargas has developed a solution to problematic PCV systems! Stock diaphragms on the gen-1 B58 Valve cover are fragile and can crack or tear over time. This can cause loss of crankcase vacuum and smoking. The VTT PCV cap replaces the factory plastic cap with a billet aluminum piece which uses a Billet Banjo fitting, and VTT's Vaccum/Boost adapter to move vacuum directly from the head ports to the manifold. This cap will also allow you to run a catch can on the low side if desired. VTT Recommends using this cap alongside their High Side Catch Can and crankcase breather for maximum efficiency. Installation is as simple as popping the stock cap off, removing the diaphragm, and placing the VTT components in place. Kit Includes: One Billet PCV Cap One Billet Banjo Fitting One Vaccum/Boost adapter One line with built-in check valve

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Bav Auto Crankcase Pressure Regulator Valve - BMW M52 M54

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T#:640207

Part#: 11617501566

In Stock

Sale - Save 20% $ 32.99

This product was last offered at the strikethrough price on
05-03-2026

$ 26.39 USD

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This product was last offered at the strikethrough price on
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$ 26.39 USD

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BMW has an ongoing issue with oil separators freezing in cold weather if driving is done before the vehicle is fully warmed up. There is often a howling noise followed by numerous oil leaks. The crankcase breather valve is used to purge the oil vapor from the engine block into the valve cover. However, sometimes condensation can cause it to freeze, causing the entire oil separator system to fail, crack, and disintegrate. Replace this and all the other components of the oil separator system to prevent damage to all the aspects of your engine. As long as you have everything off, you can rest assured that new parts will last and be reliable. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Bav Auto Crankcase Ventilation Return Hose - E46 E39 E60 Z3

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T#:638072

Part#: 11617504536

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Sale - Save 20% $ 26.99

This product was last offered at the strikethrough price on
05-03-2026

$ 21.59 USD

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This product was last offered at the strikethrough price on
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This is the BMW crankcase return line that goes from the intake manifold to the top CCV connecting hose. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Bav Auto Vent Hose - From Valve Cover to Oil Separator - E36 E39 Z3 ...

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T#:579869

Part#: 54546

Ships on Aug 11, 2026

Sale - Save 20% $ 26.99

This product was last offered at the strikethrough price on
05-03-2026

$ 21.59 USD

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$ 26.99

This product was last offered at the strikethrough price on
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$ 21.59 USD

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Bav Auto Crank Case Ventilation Valve - E31 E38 E39 M62 4.4L ...

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T#:640206

Part#: 11617501563

In Stock

Sale - Save 20% $ 47.99

This product was last offered at the strikethrough price on
05-03-2026

$ 38.39 USD

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Sale - Save 20%

$ 47.99

This product was last offered at the strikethrough price on
05-03-2026

$ 38.39 USD

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An integral part of the emissions system, the PCV valve lets the crankcase breathe. This allows proper intake and exhaust flow, resulting in proper running and operation. When the crankcase vent valve fails it can cause excessive oil consumption, engine fault codes, and poor idle. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Engine Crankcase Breather Element

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T#:35795496

Part#: 11617533400

Ships in 9 Business Days

$ 40.99 USD

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$ 40.99 USD

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Commonly referred to as the "oil separator" or PCV URO Parts is one of the leading manufacturers of high quality direct replacement aftermarket components, covering a wide range of makes and models. All of their replacement parts are manufactured to ISO 9000 certification standards, so you can expect long lasting performance from URO Parts.

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Billet 1/2" Check Valve - N54

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T#:557954

Part#: VTT-CHECK-1

Ships in 2 Business Days

$ 36.99 USD

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Vargas Turbo has you covered when you are installing a custom turbo setup. With all of the adapters you need and all the valves necessary, the only real limiting factor is your imagination!

This is a 1/2" (fits -8AN hos perfectly as well) CNC Billet check valve that can be used for a variety of uses including a vacuum/boost check valve when removing the stock PCV system, and still wanting to run the vacuum to the crankcase. Rated at over 100 psi, with a cracking psi of .25psi.

This part fits the following BMW engines:
2006-2012 N54

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Billet Check Valve - 10 Barb

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T#:597641

Part#: VTT-CHECK-2

Ships in 3 Business Days

$ 36.99 USD

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Vargas Turbo has you covered when you are installing a custom turbo setup. With all of the adapters you need and all the valves necessary, the only real limiting factor is your imagination!

VTT CNC ORB Plug - -10AN

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T#:642075

Part#: VTT-10ORB

Ships on Jul 29, 2026

$ 23.99 USD

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$ 23.99 USD

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Flapper Delete Fitting - N54

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T#:557962

Part#: VTT-FLAPPER-DELE

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$ 57.99 USD

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$ 57.99 USD

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Vargas Turbo has you covered when you are installing a custom turbo setup. With all of the adapters you need and all the valves necessary, the only real limiting factor is your imagination!

The VTT PCV Flapper delete is used to get rid of the factory flapper, and add a -10 fitting on N54 powered vehicles. This will allow you to run a single or dual external catch can, or your own custom set up.

This fitting is made from 6061-T6 aircraft aluminum anodized black and comes with O-ring, and a stainless steel holding clip.

This part fits the following BMW engines:
2006-2012 N54

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Bav Auto Intake Manifold Cover w/ PCV Valve - BMW E31 E32 E34 E38 M6...

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T#:639843

Part#: 11617501562

Special Order: No Guaranteed ETA

Sale - Save 15% $ 59.99

This product was last offered at the strikethrough price on
05-03-2026

$ 50.99 USD

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This product was last offered at the strikethrough price on
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$ 50.99 USD

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An integral part of the emissions system, the PVC valve lets the crankcase breathe. This allows proper intake and exhaust flow, resulting in proper running and operation. Often split from underhood heat and age, this vents excess oil into the engine compartment. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Bav Auto Upper Oil Separator Vent Tube - E36 E46 E60 E84 Z3 Z4 M54 M5...

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T#:640502

Part#: 11617504535

In Stock

Sale - Save 20% $ 24.99

This product was last offered at the strikethrough price on
05-03-2026

$ 19.99 USD

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$ 24.99

This product was last offered at the strikethrough price on
05-03-2026

$ 19.99 USD

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Runs from the top of the oil separator up to rear of the intake manifold. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Oil Separator Valve

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5X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:22064588

Part#: AS819M

In Stock

$ 41.99

This product was last offered at the strikethrough price on
05-03-2026

$ 31.99 USD

Limited Qty Sale

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$ 41.99

This product was last offered at the strikethrough price on
05-03-2026

$ 31.99 USD

Limited Qty Sale

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BMW has an ongoing issue with oil separators freezing in cold weather if driving is done before the vehicle is fully warmed up. There is often a howling noise followed by numerous oil leaks. The crankcase breather valve is used to purge the oil vapor from the engine block into the valve cover. However, sometimes condensation can cause it to freeze, causing the entire oil separator system to fail, crack, and disintegrate.

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Oil Separator Hose - E46, Z4

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T#:579880

Part#: 55080

In Stock

Sale - Save 20% $ 24.99

This product was last offered at the strikethrough price on
05-03-2026

$ 19.99 USD

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Qty

Sale - Save 20%

$ 24.99

This product was last offered at the strikethrough price on
05-03-2026

$ 19.99 USD

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Cold climate version for extra insulation! Fits all E46 and Z4 chassis equipped with an M54 engine.

PCV Adapter Fitting N54

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T#:557961

Part#: VTT-PCV-ADAPTER

Ships on Jul 29, 2026

$ 145.99 USD

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$ 145.99 USD

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Vargas Turbo has you covered when you are installing a custom turbo setup. With all of the adapters you need and all the valves necessary, the only real limiting factor is your imagination!

This is the adapter fitting that is required to convert your N54 to external PCV if you want to keep your crankcase under vacuum at idle, and anytime you have a vacuum condition in your intake manifold. They are made from 6061-T6 with black anodizing for a long-lasting finish. Includes complete adapter, with all o-rings, and retaining clip.

This must be used in conjunction with the Vargas billet check valve, and PCV delete fitting or requires plugging of the intake PCV ports. Installs inline on the throttle body, and adds a -8AN male to adapt to a catch cans, or any custom set up.

Made from 6061-T6 with black anodizing for a long-lasting finish. Includes complete adapter, with all o-rings, and retaining clip

This part fits the following BMW engines:
2006-2012 N54

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Oil Separator Valve

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T#:22064593

Part#: AS826M-D851

Ships on Aug 5, 2026

$ 62.99 USD

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$ 62.99 USD

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BMW has an ongoing issue with oil separators freezing in cold weather if driving is done before the vehicle is fully warmed up. There is often a howling noise followed by numerous oil leaks. The crankcase breather valve is used to purge the oil vapor from the engine block into the valve cover. However, sometimes condensation can cause it to freeze, causing the entire oil separator system to fail, crack, and disintegrate.

Show More Show Less

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Oil Separation & Breather System
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