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Oil Separators & Vent lines

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DISPLAYING 1 to 16 (of 27 products)
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OILSEPKIT997S
Product Information
Product Information
Oil separator kit, complete. 
oematch


Fits:
Porsche 997.1 Carrera 2S / 4S 3.8L

Kit contains  3 oil separators, feed and return lines and breather lines.



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

OILSEPKIT997S
99710703801
99710713800
99710714301
99710714603
99710602402
99710602802
99710714502
90038502301

The product you are viewing cross references to these numbers
OILSEPKIT997SP
Product Information
Product Information
Oil separator kit, complete. 

porsche

Fits:

Porsche 997.1 Carrera 2S / 4S 3.8L

Kit contains  3 oil separators, feed and return lines and breather lines.
All components are Genuine Porsche parts



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

OILSEPKIT997SP
99710703801
99710713800
99710714301
99710714603
99710602402
99710602802
99710714502

The product you are viewing cross references to these numbers
Special Order item
99610702652
Product Information
Product Information
Oil Separator. One of the most common failures in the Boxster or 996 is the Air/Oil Separator, also referred to as the AOS.

porsche

Fits:
Porsche 996 3.6L
Porsche 997 3.6L

Oil Separator. One of the most common failures in the Boxster or 996 is the Air/Oil Separator, also referred to as the AOS.

The AOS is basically a small diaphragm distillery which distills the minute amounts of oil mist in the crankcase, liquifies it and sends it back to the crankcase. The "clean" air is now sent into the air intake (after the throttle body) to be burned off by the engine.

When the AOS starts to fail it cannot separate all of the oil out of the mist and some liquid oil is sent to the air intake.

A few drops of oil is enough to generate the GREAT SMOKE BOMB for which our cars are famous for.
A big smoke bomb once in a while is completely normal, due to the architecture of the flat-6 engine, which may let a drop of oil flow into one of the combustion chambers sporadically.

Click pictrue for large parts diagram.
Diagram Ref No 1.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99610702652
99610702651
99610702650
99610702652

The product you are viewing cross references to these numbers
99610702652/1
Product Information
Product Information
Oil / air Separator.

Fits:
Porsche 996 3.6L
Porsche 997 3.6L

Oil Separator. One of the most common failures in the Boxster or 996 is the Air/Oil Separator, also referred to as the AOS.

The AOS is basically a small diaphragm distillery which distills the minute amounts of oil mist in the crankcase, liquifies it and sends it back to the crankcase. The "clean" air is now sent into the air intake (after the throttle body) to be burned off by the engine.

When the AOS starts to fail it cannot separate all of the oil out of the mist and some liquid oil is sent to the air intake.

A few drops of oil is enough to generate the GREAT SMOKE BOMB for which our cars are famous for.
A big smoke bomb once in a while is completely normal, due to the architecture of the flat-6 engine, which may let a drop of oil flow into one of the combustion chambers sporadically.

Diagram Ref No 1.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99610702652
99610702651
99610702650
99610702652

The product you are viewing cross references to these numbers
Special Order item
99610714530
Product Information
Product Information
Breather hose, Oil separator to crankcase.

porsche

Fits:
Porsche 996 C2 / C4 / C4S 3.6L 2002-05
Porsche 997.1 C2 / C2S / C4 / C4S 3.6L 2005-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 5

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Related, superseded, cross reference or alternative numbers for comparison.

99610714530
99610714530

The product you are viewing cross references to these numbers
99610714530/1
Product Information
Product Information
Breather hose, Oil separator to crankcase.

oematch

Fits:
Porsche 996 C2 / C4 / C4S 3.6L 2002-05
Porsche 997.1 C2 / C2S / C4 / C4S 3.6L 2005-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 5

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Related, superseded, cross reference or alternative numbers for comparison.

99610714530
99610714530
012258
99610714530

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Special Order item
99710714301
Product Information
Product Information
Breather line. Primary to secondary oil separator. Cylinder 1-3.

porsche

Fits:
Porsche 997.1 Carrera 4/ Carrera 4S 3.8L 2004-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 7

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Related, superseded, cross reference or alternative numbers for comparison.

99710714301
99710714301

The product you are viewing cross references to these numbers
99710714301/1
Product Information
Product Information
Breather line. Primary to secondary oil separator. Cylinder 1-3.

oematch

Fits:
Porsche 997.1 Carrera 4/ Carrera 4S 3.8L 2004-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 7

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99710714301
99710714301

The product you are viewing cross references to these numbers
Special Order item
99710714603
Product Information
Product Information
Breather line. Primary to secondary oil separator. Cylinder 4-6.

porsche

Fits:
Porsche 997.1 Carrera 4/ Carrera 4S 3.8L 2004-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 5
99710714603/1
Product Information
Product Information
Breather line. Primary to secondary oil separator. Cylinder 4-6.

oematch

Fits:
Porsche 997.1 Carrera 4/ Carrera 4S 3.8L 2004-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 5

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99710714603
99710714603

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Special Order item
99610622652
Product Information
Product Information
Plastic coolant hose connector for Oil separator. Porsche 996 / 997

porsche

Fits:
Porsche 996 C2 / C4 / C4S 1998-05
Porsche 997 CARRERA 2005-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 18

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99610622652
99610622651
99610622652

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99610622652PRM
Product Information
Product Information
HD Aluminium construction Coolant hose connector for Oil separator.

Fits:
Porsche 996 C2 / C4 / C4S 1998-05
Porsche 997 CARRERA 2005-08

Diagram ref no 18

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Related, superseded, cross reference or alternative numbers for comparison.

99610622652PRM
99610622652
99610622651

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Special Order item
99610622352
Product Information
Product Information
Crankcase Housing Ventilation Hose.
Ensure reliable crankcase ventilation on your Porsche with this genuine OEM breather hose. Designed to connect the crankcase/bleed port to the PCV/intake system, this hose helps maintain correct vacuum/pressure balance, removes oil vapour efficiently and supports engine health in models such as the 911 (996 / 997.1 series).

Fits:
  • 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 997 MK1 Carrera 2 3.6L 2005-08
  • Porsche 997 MK1 Carrera 4 3.6L 2005-08

Diagram Ref No 19

What This Product Does:

  • The crankcase ventilation hose provides a path for filtered crankcase gases (blow-by, vapours, oil mist) to be routed from the engine’s crankcase or oil separator back into the intake or PCV (positive crankcase ventilation) system rather than being vented uncontrolled.
  • It helps maintain correct engine vacuum/pressure balance within the crankcase, removes oil vapours, prevents buildup of excess pressure that could cause leaks or gasket failures, and supports emissions compliance.

Symptoms Of Wear Or Failure:
  • Visible cracks, splits or brittleness in the hose; rubber/engine bay hoses degrade under heat/oil/vapour over time.
  • Oil residue, grime or wetness around the hose or its connectors — if vapour is leaking, you may see oil-moisture deposit around the breather circuit.
  • Mis-fires, rough idle or engine running poorly — because un-metered air (via a damaged breather hose) may be introduced, altering the air/fuel ratio.
  • Check Engine Light (CEL) or fault codes concerning intake air leak, crankcase pressure or PCV system faults.
  • Oil smells in the engine bay / smoke from the breather area — indicating the hose may no longer be securing the vapours correctly.

Why Replacement Matters:
  • Protects engine internals & seals: Proper ventilation prevents excessive crankcase pressure which can force oil past seals or gaskets, causing leaks or damage.
  • Maintains performance & emissions: A damaged breather hose can upset engine vacuum and air-fuel mixture, affecting power, idle quality and emissions.
  • Prevents bigger failures: A failing hose is inexpensive; ignoring it could lead to more costly repairs (seal replacement, engine bay oil contamination, intake system clean-up).



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99610622352
99610622352
99610622351

The product you are viewing cross references to these numbers
Special Order item
99610124151
Product Information
Product Information
Crankcase oil separator gasket, 1-3 cyl.

porsche

Fits:
Porsche 986 Boxster 1997-04
Porsche 987.1 Boxster 2005-08
Porsche 987C.1 Cayman 2005-08
Porsche 996 Carrera 3.4L / 3.6L 1998-05
Porsche 997.1 Carrera 3.6L / 3.8L 2005-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 20

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99610124151
99610124251
99610124151
280.300

The product you are viewing cross references to these numbers
Special Order item
99710714502
Product Information
Product Information

Engine oil separator breather hose. From air oil separator to engine.

porsche

Fits:
Porsche 997.1 Carrera S / Carrera 4S 2005-08

Click 'Zoom in' for large parts diagram.
Diagram ref no 8



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99710714502
99710714502

The product you are viewing cross references to these numbers
99710714502/1
Product Information
Product Information

Engine oil separator breather hose. From air oil separator to engine.

Fits:
Porsche 997.1 Carrera S / Carrera 4S 2005-08

Diagram ref no 8



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99710714502
99710714502

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DISPLAYING 1 to 16 (of 27 products)
1 2
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About Oil Separators & Vent lines

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.

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