Emissions System

Fuel Tank Breather Valve

T#:25075803

Part#: 13907643106

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05-03-2026

$ 55.19 USD

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

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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Bav Auto Crankcase Pressure Regulator Valve - BMW M52 M54

T#:640207

Part#: 11617501566

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

$ 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

T#:638072

Part#: 11617504536

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

$ 21.59 USD

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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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Crank Case Vent Hose Kit - S63 4.4L Engine

T#:23913949

Part#: CRNKVENTKITKT

Ships in 5 Business Days

$ 224.99 USD

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Elevate your S63 4.4L engine's capabilities with our meticulously designed Crank Case Vent Hose Kit. Crafted from premium-grade materials, this kit ensures superior ventilation, mitigating pressure accumulation within the engine, thereby enhancing its overall performance.

Engineered to precise specifications, our kit seamlessly replaces the OEM vent hoses, guaranteeing a perfect fit. By reducing stress on the engine, it prolongs its lifespan and maintains peak functionality. Rely on this kit to provide unparalleled performance and unwavering reliability for your S63 4.4L engine.

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

T#:579869

Part#: 54546

Ships on Aug 11, 2026

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

$ 21.59 USD

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Performance Oil Separator Kit - M52/S52

T#:51356040

Part#: 059015LA02KT2KT

Ships on Oct 5, 2026

Sale - Save 19% $ 104.99

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

$ 84.77 USD

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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)

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Engine Oil Separator Package - Level 2 - E46 325, E39 525i M54 ...

T#:24344785

Part#: M54OILSEPKT

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05-03-2026

$ 133.54 USD

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If you need to perform a complete oil separator system service, this Level 2 kit provides you with all of the main components necessary to service your engine oil separator system. This Level 2 kit includes the following: Oil Separator Hose from oil separator to dipstick tube Hose from oil separator to valve cover Hose from intake manifold back to the connector hose Hose from oil separator up to the intake manifold Throttle body gasket Throttle body inlet boot ICV rubber grommet Oil dipstick tube o-ring seal It is highly recommended to replace the oil dipstick tube with the updated design by BMW as this also a common place for sludge to build up.

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

T#:640206

Part#: 11617501563

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

T#:639843

Part#: 11617501562

Special Order: No Guaranteed ETA

Sale - Save 15% $ 59.99

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05-03-2026

$ 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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Oil Separator Hose - E46, Z4

T#:579880

Part#: 55080

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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.

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

T#:640502

Part#: 11617504535

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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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Rear Oxygen Sensor Set - N52, N54

T#:55353594

Part#: 11787545074/5KT2

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$ 366.99 USD

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Sluggish oxygen sensors do a lot more than just light up your dashboard with an annoying Check Engine Light—they directly choke your BMW’s performance.

Front Oxygen Sensor Set - E9x, E82, E88, Z4

T#:55317713

Part#: BFR1/2O2SKT2

In Stock

$ 400.99

This product was last offered at the strikethrough price on
07-14-2026

$ 337.99 USD

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Over time, that degradation robs your BMW of its crisp throttle response, tanks your fuel economy, and leaves you staring at a failed emissions ticket

Bosch Oxygen Sensor Set - Pre and Post Catalytic Converter - N55 ...

T#:55857772

Part#: 11787589475KT2

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$ 335.99 USD

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$ 335.99 USD

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Extreme exhaust heat and carbon buildup degrade your factory oxygen sensors over time, sending lazy data to your DME and robbing you of performance.

Bosch Oxygen Sensors - Bank 1 And 2 Pre-Cat - N52

T#:56110313

Part#: 11787558055KT

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$ 307.99 USD

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Your engine's air fuel ratio needs to be dead on. Worn out factory pre-cat oxygen sensors delay vital data to the DME, leading to sub optimal fueling, lost horsepower, and dangerous hesitation under load.

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O2 Sensor Bung and Plug

T#:339000

Part#: TEN9949O2S

Ships in 6 Business Days

Starting at $ 12.95 USD

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Starting at $ 12.95 USD

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This weld-in bung allows an O2 sensor to be screwed into your exhaust system. It's required for custom exhaust systems, and is also useful for air/fuel ratio measurements when dyno testing.

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Sub-Categories

Fuel Tank Breather Valve

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

Bav Auto Crankcase Pressure Regulator Valve - BMW M52 M54

Bav Auto Crankcase Ventilation Return Hose - E46 E39 E60 Z3

Crank Case Vent Hose Kit - S63 4.4L Engine

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

Performance Oil Separator Kit - M52/S52

Engine Oil Separator Package - Level 2 - E46 325, E39 525i M54 ...

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

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

Oil Separator Hose - E46, Z4

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

Rear Oxygen Sensor Set - N52, N54

Front Oxygen Sensor Set - E9x, E82, E88, Z4

Bosch Oxygen Sensor Set - Pre and Post Catalytic Converter - N55 ...

Bosch Oxygen Sensors - Bank 1 And 2 Pre-Cat - N52

O2 Sensor Bung and Plug

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