Breather Pipes

Breather Hose.
Restore the engine ventilation routing on your Porsche 911 (996 / 997 series) with this genuine breather hose. This hose is located at the top of the oil cooler and connects the breather or ventilation circuit, ensuring proper air/oil vapour flow and system integrity.

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 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08

Diagram Ref No 30

What This Product Does:

• The breather hose is part of the engine’s ventilation or crankcase/air-oil management system. In this case, it's described as being located at the top of the oil-cooler, which may mean it connects the crankcase ventilation or engine breather output back into the intake or another system.
• Its main function: to provide a path for gases (blow-by, vapor, pressure) from the engine or oil-cooler area back into the intake system or safe discharge path.
• The hose must withstand engine heat, pressure/vacuum cycles, vibrations, and exposure to oil or vapour, and provide a leak-free connection.
• Proper functioning helps maintain correct crankcase pressure, prevents undue pressure build-up or vacuum, helps control emissions, keeps the oil cooler circuit operating correctly, and ensures the engine’s ventilation system does not allow unintended air or oil vapour to escape or enter in the wrong way.

Symptoms Of Wear Or Failure:

• Oil vapour or smell around the engine compartment, especially near the oil cooler area or hose routing, indicating leakage of crankcase gases.
  
• Visible cracks, splits, brittleness, or hose collapse — old hoses can harden, crack or collapse internally causing blockage or leakage.
  
• Unusual engine behaviour: e.g., increased oil consumption, engine smoking slightly, or unusual intake/vacuum behaviour — if ventilation is compromised.
  
• Check engine or emission warnings: A compromised breather hose may lead to induction of unmetered air or vapours, affecting engine management.
  
• Oil cooler area contamination: Because the hose is described as located at the top of the oil cooler, if oil or vapour-contaminated deposits are visible there, the hose may be failing.
  
  

Why Replacement Matters:

• Maintains correct engine ventilation: A good breather hose ensures proper crankcase/ventilation flow, and prevents pressure build-up or vacuum conditions that can lead to leaks or part failures (seals, gaskets).
  
• Protects the oil-cooler circuit and engine components: Because this hose is located at the oil-cooler top, replacing it helps ensure the oil cooler and associated hoses remain uncontaminated by vapour or oil mist escaping via degraded hoses.
  
• Improves reliability: Since these hoses are subject to heat, pressure and ageing, replacing them proactively avoids sudden failure, which could leave the car stranded or cause engine issues.

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

99610623053

The product you are viewing cross references to these numbers

Breather Hose.
Restore the integrity of your Porsche engine's oil cooling system with this OE Match Engine Oil Cooler Vent Hose

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 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08

Diagram Ref No 30

The vent hose forms part of the engine oil cooler system, providing the necessary connection between associated components and helping the system operate correctly. Positioned within the engine compartment, the hose is continually exposed to heat, vibration and temperature cycling, which can cause the original material to harden and deteriorate with age.

Replacing a brittle, cracked or damaged hose helps maintain a secure system and reduces the risk of leaks or further deterioration.

What Does an Engine Oil Cooler Vent Hose Do?

The oil cooler vent hose forms part of the connections associated with the engine oil cooling system. Its purpose is to maintain the correct routing and ventilation between the relevant components while providing a flexible connection capable of accommodating engine movement and vibration.

A serviceable hose helps provide:

Correct operation of the associated oil cooler system Secure connection between components Resistance to engine movement and vibration Reliable sealing and system integrity

Why Do Oil Cooler Vent Hoses Fail?

Engine compartment hoses naturally deteriorate with age. Continuous exposure to heat causes the material to gradually lose flexibility, while vibration and repeated heating and cooling cycles can accelerate deterioration.

Common causes include:

• Age and high mileage
• Constant engine heat
• Repeated heat cycles
• Rubber becoming hard or brittle
• Cracking around connection points
• Oil and chemical contamination
• Engine vibration
• Previous removal or incorrect installation

Older hoses may appear serviceable externally but can crack when disturbed during maintenance.

When Should the Hose Be Replaced?

Replacement should be considered if:

• Cracks or splits are visible
• The hose has become hard or brittle
• Connections are loose or deteriorated
• Leakage or residue is visible around the hose
• The hose is damaged during removal
• The oil cooler system is being serviced
• The engine is undergoing major maintenance or refurbishment

Preventative replacement is particularly worthwhile when surrounding components have already been removed, avoiding additional labour should an ageing hose fail later.

Porsche Engine Oil Cooler Hoses & Cooling System Components

The engine oil cooling system plays an important role in maintaining stable operating temperatures and protecting internal engine components. Hoses and connections within the system are therefore important service items, particularly as Porsche vehicles become older.

Heat, vibration and age can cause original hoses to become brittle, cracked or unreliable. Inspecting and replacing deteriorated hoses during oil cooler or engine maintenance helps prevent leaks and provides greater confidence in the integrity of the system.

When replacing an oil cooler vent hose, it is also worthwhile inspecting nearby hoses, connectors, seals and fittings for similar age-related deterioration.

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

99610623053

The product you are viewing cross references to these numbers

Hose clamp, 12-22 mm - Various Applications.



Fits:
Porsche 911 - 1978 to 1989
Porsche 964 - 1989 to 1994
Porsche 993 - 1994 to 1998
Porsche 986 Boxster - 1997 to 2004
Porsche 996 - 1997 to 2005
Porsche 997.1 - 2005 to 2008



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

99951255400

The product you are viewing cross references to these numbers

Oil separator breather hose.



Fits:
Porsche 996 3.4L C2 / C4 1997-01
Porsche 996 3.8L C2 / C4 / C4S 2001-04

Click 'Zoom in' for large parts diagram.
Diagram ref no 12

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

99610620850

The product you are viewing cross references to these numbers

Oil separator breather hose.



Fits:
Porsche 996 3.4ltr Carrera 2 / 4
Porsche 996 3.8ltr Carrera 2 / 4 / 4S


Click 'Zoom in' for large parts diagram.
Diagram ref no 12

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

99610620850

The product you are viewing cross references to these numbers

Oil separator breather hose.



Fits:
Porsche 996 3.4L C2 / C4 1997-01
Porsche 996 3.8L C2 / C4 / C4S 2001-04

Click 'Zoom in' for large parts diagram.
Diagram ref no 13

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

99610622451

The product you are viewing cross references to these numbers

Oil separator breather hose.



Fits:
Porsche 996 3.4ltr Carrera 2 / 4
Porsche 996 3.8ltr Carrera 2 / 4 / 4S

Click 'Zoom in' for large parts diagram.
Diagram ref no 13

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

99610622451

The product you are viewing cross references to these numbers

Oil separator breather hose.

Fits:
Porsche 996 3.4L 1997-2001

Diagram ref no 5

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

99610714555

The product you are viewing cross references to these numbers

Oil separator breather hose.
Replace the critical crankcase ventilation hose with our OE-match quality Oil Separator Breather Hose (P/N 99610714555), engineered specifically for the Porsche 911 (996) (1998-2001) with the 3.4 L flat-six engine.

Fits:
Porsche 996 3.4L 1997-2001

Diagram ref no 5

Why replace it?
Over time, the factory breather hose can balloon, crack or collapse, causing poor ventilation, increased crankcase pressure, oil leaks, erratic idle, and possible check-engine lights. Installing this OE-match hose restores correct system pressure and durability.

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

99610714555

The product you are viewing cross references to these numbers