Oil separator main centre. Porsche 997 3.8L C2S / C4S

Oil Separator main centre.
Oil Separator - Main Centre unit - is a direct-fit replacement for the factory crankcase ventilation system component used on Porsche 911 (997) Carrera 3.8L 2S / 4S engines. This separator plays a vital role in maintaining crankcase pressure equilibrium by separating oil mist from blow-by gases before routing clean air back into the intake manifold.

Fits:
Porsche 997 3.8L Carrera 2S / 4S 2005 - 2008

Diagram Ref No 1.

• Function: Separates oil vapours from crankcase gases to prevent oil ingestion
• Position: Engine – main centre, crankcase ventilation housing
• Benefits: OE-style fit, improved oil vapor separation, durable diaphragm construction
• Installation: Direct-fit replacement; verify hose routing and seals during reassembly

Over time, the oil separator’s diaphragm and housing can degrade from heat cycling, oil vapour, and pressure changes, leading to vacuum leaks, oil smoke, or excessive consumption.

Replace this unit when:
• You see oil residue or smoke from the exhaust or intake
• The engine shows rough idle, whistling sounds, or high vacuum
• Oil consumption has increased significantly
• During engine service or PCV system maintenance

Replacing restores balanced crankcase pressure, prevents oil ingestion, and maintains clean combustion — ensuring your Porsche 997’s 3.8L engine performs at its best.

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Related, superseded, cross reference or alternative numbers for comparison.

99710703801

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