Oil Separation & Breather System for BMW Z Series E85/6 (2003-2008)

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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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Turner Motorsport - Corporate Logo
T#:46203577
Part#: 058973LA02
In Stock
$ 101.99

This product was last offered at the strikethrough price on
06-24-2026

$ 78.99 USD
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$ 78.99 USD
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Due to weak plastic construction, the factory plastic crankcase ventilation breather hose is known to fail. After years of exposure to piping-hot engine bay temperatures and chemical-laden oil vapors, the corrugated plastic tubing can crack, crumble, or fail altogether.

We set out to bulletproof your N52 CCV system with a durable silicone breather hose, designed to provide a comprehensive upgrade and permanent replacement for the factory plastic hose. By replacing the flimsy, heat-hardened OEM plastic hose with a four-ply fluorosilicone hose, you'll experience peace of mind knowing your N52 is free from the inevitable return of oil leaks, vacuum leaks, and drivability concerns that would have been.

This breather hose is found at the front of the engine, and is used to connect the oil separator to the valve cover. It replaces OEM part number 11157522931.

Features:

Silicone construction ensures a durable replacement that is sure to outlast OE plastic
Designed as a direct replacement for the factory breather hose
Retains heating function and OE electrical connector
Design:

Four-ply wire-reinforced fluorosilicone hose is designed to resist degradation due to exposure to oil vapors
O-rings are pre-installed in OE connectors for a lasting seal
Includes pre-installed zinc-coated hose clamps for durability and corrosion resistance
Product Development:

Our Silicone CCV Hose Upgrade was designed, engineered, tested, and quality inspected by our Research and Development team in our Wadsworth, Ohio, facility. We strive for the highest level of precision and quality through leading-edge product development technology, including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modelling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.

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Turner Motorsport - Corporate Logo
T#:2895
Part#: 11617533400-E85
Ships in 1 day
Sale - Save 5% $ 406.99

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

$ 386.64 USD
Free Shipping
Sale - Save 5%
$ 406.99

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

$ 386.64 USD
Free Shipping
This Crankcase Vent / Oil Separator Repair Kit includes the updated oil separator valve, oil dipstick guide tube and hoses. This kit fits E85 Z4 2.5i Z4 3.0i 2003-2005.

This item fits the following BMWs:
2003-2006 E85 BMW Z4 2.5i Z4 3.0i
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Turner Motorsport - Corporate Logo
T#:46203579
Part#: 058981LA02
In Stock
$ 101.99

This product was last offered at the strikethrough price on
06-14-2026

$ 59.99 USD
Free Shipping
$ 59.99 USD
Free Shipping

Due to weak plastic construction, the factory plastic crankcase ventilation breather hose is known to fail. After years of exposure to piping-hot engine bay temperatures and chemical-laden oil vapors, the corrugated plastic tubing can crack, crumble, or fail altogether.

Upgrade your N52 CCV system with this durable silicone oil separator hose, designed to provide a comprehensive upgrade and permanent replacement for the factory plastic hose. By replacing the flimsy, heat-hardened OEM plastic hose with a four-ply fluorosilicone hose from Turner Motorsport, you'll experience peace of mind knowing your N52 is free from the inevitable return of oil leaks, vacuum leaks, and drivability concerns that would have been.

This hose is located underneath the intake manifold and is used to connect the oil separator to the induction tract. It replaces OEM part number 11617559530.

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URO Crankcase Vent Hose - 11157522931
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:26171673
Part#: 11157522931
In Stock
$ 39.79 USD
Free Shipping on orders $49 and up

Connecting the cyclone oil separator to the engine valve cover, this hose is crucial for maintaining optimal engine performance. Over time, exposure to heat from engine components can cause the plastic hose to become brittle, resulting in cracks, tears, or splits. These issues can lead to vacuum and oil leaks, triggering a check engine light.

  • High-quality replacement for BMW crankcase vent hose
  • Ensures optimal engine performance
  • Resistant to heat and wear
  • Helps prevent vacuum and oil leaks
  • Easy to install
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URO Oil Separator Valve - BMW E60 E90 Z4 N52
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:592960
Part#: 11617531423
In Stock
$ 57.12 USD
Free Shipping
$ 57.12 USD
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he 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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Crankcase Pressure Regulator Valve
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:373032
Part#: 11617501566
Ships in 1 Business Day
$ 25.99 USD
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$ 25.99 USD
Free Shipping on orders $49 and up
Commonly referred to as the "oil separator" or PCV

Upper Oil Separator Vent Tube
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URO - Corporate Logo
T#:362022
Part#: 11617504535
Ships in 1 Business Day
$ 20.99 USD
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$ 20.99 USD
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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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URO Crankcase Ventilation Return Hose - 11157567801
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:26171675
Part#: 11157567801
Ships in 1 Business Day
$ 39.99 USD
Free Shipping on orders $49 and up

For your BMW's optimal performance, ensure the functionality of the hose connecting the oil dipstick to the crankcase vent valve. Positioned below the intake manifold, this hose is susceptible to clogging with oil film and condensation, leading to potential failure over time. Cracks and swelling in old hoses can result in oil and vacuum leaks, compromising engine performance.

  • Essential component for BMW engine functionality
  • Prevents clogging and potential hose failure
  • Minimizes oil and vacuum leaks
  • Convenient replacement when replacing crankcase vent valve
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Crankcase Ventilation Dipstick Hose - BMW M52TU M54
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:359570
Part#: 11157532629
Ships in 1 Business Day
$ 12.99 USD
Free Shipping on orders $49 and up

This tube runs from the oil separator to the lower dipstick tube.

 

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.

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Return Pipe
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URO - Corporate Logo
T#:372847
Part#: 11617504536
Ships in 1 Business Day
$ 16.99 USD
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$ 16.99 USD
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Runs from the intake manifold back to connecting hose
Crankcase Ventilation Hose
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:378279
Part#: 11617533398
Ships in 1 Business Day
$ 21.99 USD
Free Shipping on orders $49 and up
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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"Cold Climate" Crankcase Pressure Regulator Valve
Superior performance for both warm and cold climates
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:376770
Part#: 11617533400
Ships in 1 Business Day
$ 70.99

This product was last offered at the strikethrough price on
04-10-2026

$ 40.99 USD
Free Shipping
$ 40.99 USD
Free Shipping
Commonly referred to as the "oil separator" or PCV


URO Crankcase Ventilation Hose - BMW M52TU M54
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:377307
Part#: 11157532649
Ships in 1 Business Day
$ 12.99 USD
Free Shipping on orders $49 and up
$ 12.99 USD
Free Shipping on orders $49 and up
From oil separator to dipstick tube
Crankcase Vent Hose - From Valve Cover to Oil Separator - E46 E39 E6...
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:2853
Part#: 11611432559
Ships in 1 Business Day
$ 14.99 USD
Free Shipping on orders $49 and up
$ 14.99 USD
Free Shipping on orders $49 and up
This Crankcase Vent Hose - From Valve Cover to Oil Separator fits BMWs with the M52 or M54 6 cylinder engine including E46 323i 325i 328i 330i E39 525i 528i 530i E60 525i 530i X3 2.5i 3.0i X5 3.0i Z3 2.5 2.8 3.0i Z4 2.5i 3.0i.

This item fits the following BMWs:
1999-2005 E46 BMW 323i 323ci 328i 328ci 330i 330ci 330xi
1999-2005 E46 BMW 325i 325ci 325xi - only with M54 engine
1999-2003 E39 BMW 528i 528i 530i
2004-2005 E60 BMW 525i 525xi 530i 530xi
2004-2006 E83 BMW X3 2.5i X3 3.0i
2000-2006 E53 BMW X5 3.0i
1999-2002 Z3 BMW Z3 2.3 Z3 2.5i Z3 2.8i Z3 3.0i
2003-2006 E85 BMW Z4 2.5i Z4 3.0i
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