Oil Separators & Vent lines
Engine Crankcase Breather Hose Kit (Silver lids)
The engine crankcase breather hose is a key part of your vehicle’s positive crankcase ventilation (PCV) system. Its main role is to route pressurized gases from the engine crankcase to the PCV valve (also called the air/oil separator). The PCV valve captures harmful oil vapers , drains them back into the engine, and redirects the cleaned air to the intake system to be burned during normal combustion.
Without a properly functioning breather hose, your engine can develop performance issues, oil leaks, and even emissions failures.
Fits:
Porsche 957 Cayenne S / GTS 4.8L 2009 - 2010
Why the Engine Crankcase Breather Hose Matters
During combustion, engines naturally produce positive crankcase pressure. This pressure combines with heat and oil vapers inside the crankcase. The breather hose is designed to handle this flow and keep your PCV system working efficiently.
Over time, however, exposure to heat, oil, and pressure makes the breather hose a common failure point. When damaged, it can cause poor performance, check engine lights, and increased emissions.
Common Symptoms of a Failing Crankcase Breather Hose
- Cracks, leaks, or breaks – Heat and oil vapers degrade rubber or plastic over time, leading to air leaks.
- Broken connectors or clips – Brittle plastic can snap during service or due to age.
- Visible damage – Hoses may split, soften, or harden, creating noticeable holes.
- Check Engine Light (CEL) – Unmetered air from a leak often triggers intake-related fault codes.
- Engine misfires or rough idle – Severe air leaks upset the air/fuel mixture, causing misfires.
Oil residue or odour – Escaping vapers leave oily deposits on the hose, engine block, and nearby components. In severe cases, you may smell burning oil.
Why You Shouldn’t Ignore a Bad Breather Hose
A faulty crankcase breather hose affects engine performance, fuel efficiency, and emissions compliance. Left untreated, it can cause long-term engine damage and costly repairs.
If you notice any of the above signs, it’s important to inspect and replace your crankcase breather hose as part of regular PCV system maintenance.
Diagram ref no 13 (Cyl 1-4) or 14 (Cyl 5-8)
NOTE: This part is compatible only with 957 Cayenne S/GTS models produced from the 2009 model year onwards. It is not compatible with earlier models equipped with the silver AOS.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810723501
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10
Engine Crankcase Breather Hose Kit
The engine crankcase breather hose is a key part of your vehicle’s positive crankcase ventilation (PCV) system. Its main role is to route pressurized gases from the engine crankcase to the PCV valve (also called the air/oil separator). The PCV valve captures harmful oil vapers , drains them back into the engine, and redirects the cleaned air to the intake system to be burned during normal combustion.
Without a properly functioning breather hose, your engine can develop performance issues, oil leaks, and even emissions failures.
Fits:
Porsche 957 Cayenne S / GTS 4.8L 2009 - 2010
Why the Engine Crankcase Breather Hose Matters
During combustion, engines naturally produce positive crankcase pressure. This pressure combines with heat and oil vapers inside the crankcase. The breather hose is designed to handle this flow and keep your PCV system working efficiently.
Over time, however, exposure to heat, oil, and pressure makes the breather hose a common failure point. When damaged, it can cause poor performance, check engine lights, and increased emissions.
Common Symptoms of a Failing Crankcase Breather Hose
- Cracks, leaks, or breaks – Heat and oil vapers degrade rubber or plastic over time, leading to air leaks.
- Broken connectors or clips – Brittle plastic can snap during service or due to age.
- Visible damage – Hoses may split, soften, or harden, creating noticeable holes.
- Check Engine Light (CEL) – Unmetered air from a leak often triggers intake-related fault codes.
- Engine misfires or rough idle – Severe air leaks upset the air/fuel mixture, causing misfires.
Oil residue or odour – Escaping vapers leave oily deposits on the hose, engine block, and nearby components. In severe cases, you may smell burning oil.
Why You Shouldn’t Ignore a Bad Breather Hose
A faulty crankcase breather hose affects engine performance, fuel efficiency, and emissions compliance. Left untreated, it can cause long-term engine damage and costly repairs.
If you notice any of the above signs, it’s important to inspect and replace your crankcase breather hose as part of regular PCV system maintenance.
Diagram ref no 13 (Cyl 1-4) or 14 (Cyl 5-8)
NOTE: This part is compatible only with 957 Cayenne S/GTS models produced from the 2009 model year onwards. It is not compatible with earlier models equipped with the silver AOS.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810723603
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10

Fits:
Porsche 957 Cayenne S / GTS 2009-10
Click 'Zoom in' for large parts diagram.
Diagram ref no 13 (Cyl 1-4) or 14 (Cyl 5-8)
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810723
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10
Fits:
Porsche 957 Cayenne S / GTS 4.8L 2009 - 2010
Diagram ref no 13 (Cyl 1-4) or 14 (Cyl 5-8)
NOTE: This part is compatible only with 957 Cayenne S/GTS models produced from the 2009 model year onwards. It is not compatible with earlier models equipped with the silver AOS.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810723
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10

Fits:
Porsche 957 Cayenne S / GTS >>2008
Click 'Zoom in' for large parts diagram.
Diagram ref no 13 (Cyl. 1-4) or 14 (Cyl 5-8).
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810723
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10

Fits:
Porsche 957 Cayenne S / GTS >>2008
Click 'Zoom in' for large parts diagram.
Diagram ref no 13 (Cyl. 1-4) or 14 (Cyl 5-8).
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810723
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10
Fits:
Porsche Cayenne 957 (9PA1) S / GTS 4.8L 2007-10
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810743700
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10
O-RING SIZE (MM): 20 x 3.8
Fits:
Porsche Cayenne 957 4.8L S / GTS 2007-10
Click 'Zoom in' for large parts diagram.
Diagram ref no 17
- Porsche 957 Cayenne S/GTS 4.8L 2007-10

Fits:
Porsche 957 Cayenne S / GTS 4.8L 2007-10
Engine type 4801
Click 'Zoom in' for large parts diagram.
Diagram ref no 19
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810724502
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10

Fits:
Porsche 957 Cayenne S / GTS 4.8L 2007-10
Engine type 4801
Click 'Zoom in' for large parts diagram.
Diagram ref no 19
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810724502
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10
Fits:
Porsche 957 Cayenne S / GTS 4.8L 2007-10
Click 'Zoom in' for large parts diagram.
Diagram ref no 1
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
94810724702
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne S/GTS 4.8L 2007-10
Oil Separators & Vent Lines – Maintain Clean Airflow and Engine Efficiency
The oil separator and vent line system plays a critical role in your Porsche’s crankcase ventilation process. By separating oil vapour from the engine’s blow-by gases, these components ensure only clean air is returned to the intake system — reducing emissions, preventing carbon build-up, and maintaining consistent engine performance.
At Design911, we stock a complete range of oil separators, breather hoses, and vent lines designed for Porsche engines of all generations. Manufactured from high-grade, heat- and oil-resistant materials, these components are built to handle the demands of high-performance driving, ensuring a tight seal, proper ventilation, and long-lasting reliability.
Whether you’re maintaining a daily-driven 911 or servicing a track-ready Cayman, our oil separators and vent lines help preserve your engine’s efficiency, longevity, and power output.
What Do Oil Separators & Vent Lines Do?
The oil separator and vent system controls crankcase pressure and removes oil vapour from the air circulating inside the engine.
Core Functions:
- Separate oil vapour from crankcase gases, keeping intake air clean.
- Prevent oil from entering the intake manifold or combustion chamber.
- Maintain stable crankcase pressure for efficient engine breathing.
- Reduce harmful emissions and extend engine life.
- Support consistent power delivery and smooth idle performance.
By ensuring clean ventilation and stable pressure, these components protect your Porsche’s engine from oil contamination and performance loss.
Why Do Oil Separators & Vent Lines Fail?
Over time, heat cycles, oil vapours, and pressure fluctuations cause these parts to degrade or clog, leading to poor ventilation and increased oil consumption.
- Common Causes of Failure Include:
- Clogged internal membranes in the separator.
- Cracked or brittle vent lines from heat and age.
- Oil leaks from worn seals or connections.
- Vacuum leaks, causing rough idling or poor throttle response.
- Build-up of sludge or condensation within breather hoses.
Typical symptoms include increased oil consumption, blue exhaust smoke, rough idle, or oil leaks around the intake area, all indicating the need for inspection or replacement.
Why Replace Components?
Replacing a faulty oil separator or vent line restores proper crankcase ventilation and prevents costly engine issues like carbon build-up or oil contamination. Our precision-engineered replacements are designed for accurate fitment and long-term durability, ensuring your Porsche operates efficiently.
Key Benefits:
- Restores clean airflow and stable crankcase pressure.
- Reduces oil leaks and smoke from the exhaust.
- Improves fuel efficiency and throttle response.
- Constructed from high-quality, heat- and oil-resistant materials.
- Direct-fit compatibility with Porsche engines.
- Ideal for maintenance, rebuilds, or performance tuning.
Upgrading or replacing your oil separator and vent lines is essential for maintaining your Porsche’s smooth performance and clean emissions system.
Highlights:
- High-quality Porsche oil separators, breather hoses, and vent lines.
- Ensures clean crankcase ventilation and stable engine pressure.
- Reduces oil leaks, smoke, and carbon build-up.
- Durable construction for long-term reliability.
- Direct-fit for Porsche 911, Cayman, Boxster, Panamera & more.
- Perfect for preventive maintenance or full engine rebuilds.