Oil Separators & Vent lines
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Boxster 987 MKII 2.9L 2009-2012
- Porsche Boxster S 987 MKII 3.4L 2009-2012
- Porsche Boxster 981 2.7L 2012-16
- Porsche Boxster 981 S / GTS 3.4L 2012-16

Fits:
Porsche 986 Boxster 1997-2004
Porsche 996 Carrera 1998-2004
Diagram Ref No 11
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99951255101
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005


Fits:
Porsche 986 Boxster 1997-04
Porsche 996 C2 / C4 3.4L 1998-01
Click pictrue for large parts diagram.
Diagram Ref No 9.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99951263000
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01

Fits:
Porsche 986 Boxster - 1997 to 2004
Porsche 996 C2 / C4 3.4ltr - 1998 to 2001
Click 'Zoom in' for large parts diagram.
Diagram ref no 9
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99951263000
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01


Fits:
Porsche 987 Boxster 2005-08
Porsche 987C Cayman 2006-08
Porsche 996 C2 / C4 / C4S 3.6L 2002-05
Click pictrue for large parts diagram.
Diagram Ref No 9.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99951268309
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08


Fits:
Porsche 996 1998-02 3.4L
Porsche Boxster 986
Click 'Zoom in' for large parts diagram.
Diagram Ref No 10.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610723752
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01

Fits:
Porsche 996 1998-02 3.4L
Porsche Boxster 986
Click 'Zoom in' for large parts diagram.
Diagram Ref No 10.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610723752
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01


Fits:
Porsche 987 Boxster 2.7L / 3.2L 2005-08
Porsche 987C Cayman 2.7L / 3.4L 2005-08
Porsche 996 Carrera 3.6L 2003-05 (M96.03)
Porsche 997 Carrera 3.6L 2005-08 COUPE / CABRIO (M96.05)
Click 'Zoom in' for large parts diagram.
Diagram Ref No 10.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610717550
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
Fits:
Porsche 987 Boxster 2.7L / 3.2L 2005-08
Porsche 987C Cayman 2.7L / 3.4L 2005-08
Porsche 996 Carrera 3.6L 2003-05 (M96.03)
Porsche 997 Carrera 3.6L 2005-08 COUPE / CABRIO (M96.05)
Diagram Ref No 10.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610717550
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08

Fits:
Porsche Boxster 986 2.5L 1999
Vehicles with chassis numbers from 65X01420
Diagram Ref No 5.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610714506
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99

Fits:
Porsche Boxster 986 2.5L 1999
Vehicles with chassis numbers from 65X01420
Diagram Ref No 5.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610714506
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99

Fits:
Porsche Boxster 986 2.5L 1997>>1999
Vehicles with chassis numbers upto 65X01419
Diagram Ref No 5
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610714505
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99


Fits:
Porsche Boxster 986 2.7L
Porsche Boxster 986 3.2L
Diagram Ref No 5.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610714600
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02


Fits:
Porsche 987.2 Boxster / Boxster S 2009-12
Porsche 987C.2 Cayman / Cayman S 2009-12
Click 'Zoom in' for large parts diagram.
Diagram ref no. 1
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9A110702007
The product you are viewing cross references to these numbers
- Porsche Boxster 987 MKII 2.9L 2009-2012
- Porsche Boxster S 987 MKII 3.4L 2009-2012
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12


Fits:
Porsche 996 C2 /C4 / C4S 1999-05 (not for TURBO and GT3)
Porsche 986 Boxster 2.7L / 3.2L 2000-05
Note: We recomend a new vent line 99610794700 and new hardware 90006731601 x 2.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610792600
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005

Porsche Motorsports Air Oil Separator. A must for any M96 engine that will be used on track. Helps to reduce the amount of oil that gets into the intake manifold when tracking your Porsche Boxster, Cayman or 911 vehicle with the M96/M97 engine. Modifications will be required on vehicles not already fitted with a Motorsports AOS Requires Qty 2 bolt part number 90006731601 (sold separately).
Porsche 987.1 Boxster
Porsche 987C.1 Cayman
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
98710792600
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08


Fits:
Porsche 987.1 Boxster 2005-08
Porsche 987C.1 Cayman 2006-08
Click 'Zoom in' for large parts diagram.
Diagram ref no 4
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
98710724601
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
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.