Oil Separation & Breather System for BMW 3 Series E46 (1999-2005)

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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 S54 CSL Silicone Crankcase Vent Hose - E46 M3 Z3M
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:10681673
Part#: 018562LA02
In Stock
Sale - Save 25% $ 93.99

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

$ 70.49 USD
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Sale - Save 25%
$ 93.99

This product was last offered at the strikethrough price on
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$ 70.49 USD
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The factory rubber/plastic hoses become brittle and crack over time. Brittle and cracked hoses can cause multiple vacuum leaks that are impossible to repair without hose replacement. Vacuum leaks can cause many problems including rough running, missing, stalling at idle, and even a no-start condition.

The factory hoses offered through BMW are plastic and will yield the same results of becoming brittle and damaged over time. Our solution is a premium replacement that will outlast everyone of the OEM replacements. Our Silicone Crankcase Vent Hose can be used to replace the factory brittle hose to ensure your S54 is free from vacuum leaks and performing properly.

CSL Vent Hose (11157833649) - Silicone Crankcase Vent hose is a direct replacement

Key benefits:

Lifetime replacement of the brittle OEM plastic crankcase breather hose that is susceptible to cracking overtime from constant heat cycling

Design:

Retains OEM hose end fittings to ensure proper seal

“Black” 3 ply reinforced silicone w/ “White” Turner logo

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Turner Motorsport - Corporate Logo
T#:7196695
Part#: 018562LA01
In Stock
Sale - Save 25% $ 41.99

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

$ 31.49 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 41.99

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

$ 31.49 USD
Free Shipping on orders $49 and up
The factory rubber/plastic hoses become brittle and crack over time. Brittle and cracked hoses can cause multiple vacuum leaks that are impossible to repair without hose replacement. Vacuum leaks can cause many problems including rough running, missing, stalling at idle, and even a no-start condition. Replace the brittle or broken line that attaches between the oil separator and air box. Our Turner Silicone Crankcase Hose can be used in place of both the standard and CSL intake boxes.

Our engineers at Turner sought out to solve the degrading issues that happens with the factory crankcase vent hose and found the best solution is a silicone replacement. Our Turner Silicone Crankcase Vent Hose can be used to replace the factory brittle hose to prevent vacuum leaks and lackluster performance. Simply take your factory crankcase vent hose and remove the ends; the factory ends can be installed on the new Silicone Vent Hose with the supplied clamps for a tight seal.

Turner Silicone Crankcase Vent Hose replaces the following part #'s:

CSL Vent Hose (11157833649) - Silicone Crankcase Vent hose is a direct replacement
Non-CSL Vent Hose(11157831311) - Silicone hose will make a "U" bend with direct fitment and can also be trimmed for your own preferable fit.

- Key benefits:

Lifetime replacement of the brittle OEM plastic crankcase breather hose that is susceptible to cracking overtime from constant heat cycling
- Design:

Turner logo forward facing when hood is open
Retains OEM hose end fittings to ensure proper seal and reduce cost
“Black” 3 ply reinforced silicone w/ “White” Turner logo
includes 2 German style 430 stainless worm-drive clamps for installation
- Special care instructions:

Do not overtighten hose clamps, hand tight is recommended.
Carefully cut the OEM plastic casing from both plastic fittings for reuse

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AN CSL Crankcase Vent Hose - (00-04.5)
For Vehicles Fitted with a CSL Intake Plenum
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:16907195
Part#: 043464LA02
In Stock
Sale - Save 20% $ 178.99

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

$ 143.19 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 178.99

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

$ 143.19 USD
Free Shipping on orders $49 and up

A combination of billet fittings and AN lines for an upgraded and serviceable crankcase vent hose. Attaches between the oil separator and the CSL air box.

The factory rubber/plastic hoses become brittle and crack over time. Brittle and cracked hoses can cause multiple vacuum leaks that are impossible to repair without hose replacement. Vacuum leaks can cause many problems including rough running, missing, stalling at idle, and even a no-start condition. The factory hoses offered through BMW are plastic and will yield the same results of becoming brittle and damaged over time.

We have created a full motorsport style solution with our CSL Crankcase made from machined 6061 billet aluminum with AN style fittings and nylon fiber braided lines. This is a fully serviceable replacement that will outlast every one of the OEM replacements. Our AN crankcase line can be used to replace the factory brittle hose to ensure your S54 is free from vacuum leaks and performing properly.

OEM CSL Vent Hose (11157833649) - Direct Replacement

Key benefits:

Lifetime replacement of the brittle OEM plastic crankcase breather hose
Fully Serviceable
Motorsport Aesthetic to compliment your CSL Intake Plenum
Design:

Fittings are made from billet 6061-T6 aluminum and finished in Type II black anodizing
Pre-anodized machined Turner branding
Nylon fiber braided lines
Fittings are a direct replacement for the plastic OEM fittings

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CSL Crankcase Vent Hose - AN Lines and Fittings (04.5-06)
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:17405917
Part#: 043464LA03
In Stock
Sale - Save 20% $ 177.99

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

$ 142.39 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 177.99

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

$ 142.39 USD
Free Shipping on orders $49 and up

A combination of billet fittings and AN lines for an upgraded and serviceable crankcase vent hose. Attaches between the oil separator and the CSL air box.

The factory rubber/plastic hoses become brittle and crack over time. Brittle and cracked hoses can cause multiple vacuum leaks that are impossible to repair without hose replacement. Vacuum leaks can cause many problems including rough running, missing, stalling at idle, and even a no-start condition. The factory hoses offered by BMW are plastic and will yield the same results of becoming brittle and damaged over time.

We have created a full motorsport-style solution with our CSL Crankcase made from machined 6061 billet aluminum with AN-style fittings and nylon fiber braided lines. This is a fully serviceable replacement that will outlast every one of the OEM replacements. Our AN crankcase line can be used to replace the factory brittle hose to ensure your S54 is free from vacuum leaks and performing properly.

OEM CSL Vent Hose (11157833649) - Direct Replacement for cars with secondary shut-off valve. (11157834056)

Key benefits:

Lifetime replacement of the brittle OEM plastic crankcase breather hose
Fully Serviceable
Motorsport Aesthetic to compliment your CSL Intake Plenum
Design:

Fittings are made from billet 6061-T6 aluminum and finished in Type II black anodizing
Pre-anodized machined Turner branding
Nylon fiber braided lines
Fittings are a direct replacement for the plastic OEM fittings
Not for sale or use in the state of California on any pollution-controlled vehicle as per the California Air Resources Board.

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Bremmen Parts - Corporate Logo
T#:2528129
Part#: 11617533400S1
In Stock
Sale - Save 14% $ 110.99

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

$ 94.99 USD
Free Shipping on orders $49 and up
Sale - Save 14%
$ 110.99

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

$ 94.99 USD
Free Shipping on orders $49 and up
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 all the components of the oil separator system together 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. Don't forget to order a valve cover gasket, throttle body gasket, and a new intake boot to make your separator change easier and more comprehensive.
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Crankcase Vent Hose
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:30629661
Part#: 11157831311
In Stock
Sale - Save 21% $ 30.99

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

$ 24.47 USD
Free Shipping on orders $49 and up
Sale - Save 21%
$ 30.99

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

$ 24.47 USD
Free Shipping on orders $49 and up

Bremmen Oil Separator Kit - Level 1 - E39 E46 E83 Z3 Z4
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:641646
Part#: 11617501566S1
In Stock
Sale - Save 15% $ 95.99

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

$ 81.59 USD
Free Shipping
Sale - Save 15%
$ 95.99

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

$ 81.59 USD
Free Shipping
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 all the components of the oil separator system together to prevent damage to all the aspects of your engine. Level 1 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
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Bremmen Crankcase Ventilation Hose - E39 E53 E60 E83 E46
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:640147
Part#: 11611432559
In Stock
Sale - Save 22% $ 23.99

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

$ 18.76 USD
Free Shipping on orders $49 and up
Sale - Save 22%
$ 23.99

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

$ 18.76 USD
Free Shipping on orders $49 and up
Crankcase Vent Hose - From Valve Cover to Oil Separator - Fit BMWs with the M52 or M54 6 cylinder engine

Crankcase Ventilation Hose
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:30629689
Part#: 11157532649
In Stock
Sale - Save 24% $ 15.99

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

$ 12.23 USD
Free Shipping on orders $49 and up
Sale - Save 24%
$ 15.99

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

$ 12.23 USD
Free Shipping on orders $49 and up