Crankcase breather hose. Porsche 987.2/981 Boxster / Cayman

Crankcase breather hose.
The 9A110751501 crankcase breather hose is a factory-specified part of the air/oil separation and PCV ventilation system used on water-cooled Porsche flat-6 engines fitted to Boxster and Cayman models. It connects the engine crankcase to the air/oil separator (AOS) or ventilation circuit, allowing crankcase gases to vent safely while directing blow-by vapours through the appropriate filtration pathway.

Fits:
Porsche 987.2 Boxster 2009 - 2012
Porsche 981 Boxster 2012 - 2016
Porsche 981SP Boxster Spyder 2016
Porsche 987.2 Cayman 2009 - 2012
Porsche 981C Cayman 2014 - 2016
Porsche 981C Cayman GT4 2016

Diagram Ref No 3

A rubber/plastic crankcase breather hose, part of the PCV (positive crankcase ventilation) or AOS (air-oil separator) system, that channels crankcase vapours from the engine block to the AOS or intake/vent circuit.

This breather hose:
• Provides a secure, correctly routed pathway for crankcase blow-by gases and vapours.
• Maintains proper crankcase ventilation, helping to prevent pressure buildup, leaks, or oil-soaked vapour recirculating into the intake.
• Helps keep the intake tract and engine internals clean by ensuring only air (not oil mist) is drawn through the AOS/PCV system, preventing carbon build-up, oil deposits, smoky exhaust, and potential sensor contamination.
•  Ensures durability and reliability under normal operating conditions, including heat, vibration, and exposure to crankcase gases and oil vapour - thanks to genuine Porsche-grade materials and manufacturing.

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Related, superseded, cross reference or alternative numbers for comparison.

9A110751501

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