Coolant Hoses - Engine Bay

O-ring 39,20 x 3,00 water cooling. 

Fits:
Porsche 996 turbo - 2000 to 2005
Porsche 996 GT3 - 1999 to 2004
Porsche 997.1 turbo - 2007 to 2009
Porsche 997 GT3 - 2007 to 2011
Porsche Carrera GT - 2003 to 2006
Porsche 918 Spyder

Diagram ref no 14

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99970741040

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O-ring 39,20 x 3,00 water cooling
This OE match O-ring is a direct replacement for the original Porsche sealing ring used within the water cooling systems of Porsche 996 Turbo, 996 GT3, 997 Turbo, and 997 GT3 models. Manufactured to OE specifications, it features precise dimensions of 39.20mm x 3.00mm to ensure correct sealing performance and factory-style fitment.
Sold individually

Fits:
Porsche 996 turbo - 2000 to 2005
Porsche 996 GT3 - 1999 to 2004
Porsche 997.1 turbo - 2007 to 2009
Porsche 997 GT3 - 2007 to 2011
Porsche Carrera GT - 2003 to 2006
Porsche 918 Spyder

Diagram ref no 14

Proper sealing within the cooling system is essential for maintaining coolant pressure and preventing leaks that could lead to overheating or engine damage. OE Match construction ensures compatibility with original Porsche cooling system components and reliable sealing performance under demanding operating conditions.

Ideal for preventative maintenance, cooling system servicing, or engine rebuild work, this O-ring helps restore proper sealing integrity and reliable coolant circulation.

The O-ring creates a pressure-tight seal between cooling system components, preventing coolant leaks and maintaining correct cooling system pressure. It helps ensure efficient coolant circulation and reliable engine temperature control.

Function
• Seals coolant system connections and housings
• Prevents coolant leakage under pressure
• Maintains correct cooling system pressure
• Supports reliable engine temperature regulation
• Resists heat, coolant exposure, and pressure cycling

Cooling system O-rings harden and lose elasticity over time due to heat exposure, coolant chemicals, and pressure cycling. A deteriorated seal can cause coolant leaks, pressure loss, overheating, and potential engine damage. Replacing worn O-rings during servicing helps maintain cooling system integrity and prevents costly repairs.

When to replace
•  Coolant leaks around sealed connections
•  During cooling system disassembly or servicing
•  Signs of flattened, cracked, or hardened seals
•  Loss of coolant pressure
•  During engine rebuild or preventative maintenance

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99970741040

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O-ring – 46.7 x 3.53 – used in various applications within the car's cooling system.

Fits:
Porsche 987 Boxster 2005-12
Porsche 987 Cayman 2006-12

Porsche 981 Boxster 2012-16 
Porsche 981 Boxster Spyder 2016 
Porsche 981 Cayman 2014-16 
Porsche 981 Cayman GT4 2016 

Porsche 718 (982) Boxster 2017>> 
Porsche 718 (982) Boxster Spyder 2019>>
Porsche 718 (982) Cayman 2017>>
Porsche 718 (982) Cayman GT4 2019>>

Porsche 996 GT3 / RS 1999-05
Porsche 996 Turbo / GT2 2001-05

Porsche 997 Carrera 2005-12
Porsche 997 Turbo / GT2 RS 2007-13
Porsche 997 GT3 / RS 2007-11

Porsche 991 Carrera 2012-19
Porsche 991 Turbo / GT2 RS 2014-20
Porsche 991 GT3 / RS 2014-21

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99610680103

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O-ring – 46.7 x 3.53 – used in various applications within the car's cooling system.

Fits:
Porsche 987 Boxster 2005-12
Porsche 987 Cayman 2006-12

Porsche 981 Boxster 2012-16 
Porsche 981 Boxster Spyder 2016 
Porsche 981 Cayman 2014-16 
Porsche 981 Cayman GT4 2016 

Porsche 718 (982) Boxster 2017>> 
Porsche 718 (982) Boxster Spyder 2019>>
Porsche 718 (982) Cayman 2017>>
Porsche 718 (982) Cayman GT4 2019>>

Porsche 996 GT3 / RS 1999-05
Porsche 996 Turbo / GT2 2001-05

Porsche 997 Carrera 2005-12
Porsche 997 Turbo / GT2 RS 2007-13
Porsche 997 GT3 / RS 2007-11

Porsche 991 Carrera 2012-19
Porsche 991 Turbo / GT2 RS 2014-20
Porsche 991 GT3 / RS 2014-21

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99610680103

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Protective Ring For Engine Coolant Pipe.
Sold Each.
x2 Required Per Car.

Fits:
Porsche 996 Turbo / GT2 2001>>2005
Porsche 996 GT3 1999>>2005
Porsche 997.1 Turbo / GT2 MKI 2007>>2009
Porsche 997.1 GT3 MKI 2007>>2009
Porsche 997.2 Turbo / GT2 RS MKII 2010>>2013
Porsche 997.2 GT3 MKII 2010>>2011

Diagram Ref No 16

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99610621470

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Water coolant hose return. 

Fits:
Porsche 997.1 turbo - 2007 to 2008
Porsche 997.2 GT2 - 2001 to 2012
Porsche 997 GT3 - 2007 to 2012

Click 'Zoom in' for large parts diagram.
Diagram ref no 2 or 45

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99710632872

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Water coolant hose, return.

Fits:
Porsche 997.1 Carrera 3.6 / 3.8L 2005-08*
Porsche 997.1 Turbo 2007-09*
*for cars with Tiptronic transmission (option I249)

Click 'Zoom in' for large parts diagram.
Diagram ref no 3

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99710674205

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Water coolant hose, return.


Fits:
Porsche 997.1 2007-09*

Porsche 997.2 2010-13*
*for cars with 6-speed Manual transmission (option I480)

Click 'Zoom in' for large parts diagram.

Diagram ref no 2

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99710674106

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Water Coolant Hose, Return.

Fits:
Porsche 997.1 GT2 / GT3/RS MKI 2005>>2008

Porsche 997.2 GT2/RS / GT3/RS MKII 2009>>2012

Diagram Ref No 3

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99710688996

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Water coolant hose, return.


Fits:
Porsche 997.1 Turbo 2007-09*

Porsche 997.2 Turbo 2010-13*
*for cars with 6-speed Manual transmission (option I480), not for GT2/GT3

Click 'Zoom in' for large parts diagram.

Diagram ref no 2

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99710674107

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Water coolant hose, supply
This original Porsche coolant hose forms part of the engine cooling system, helping route coolant through the supply side of the cooling circuit and maintain correct engine temperature control.

Fits:
Porsche 997.1 2005 - 2008
Porsche 997.2 2009 - 2012

Diagram ref no 17

This hose is used in the water cooling system on selected Porsche 997 models.

What This Part Does / Functions:
• Routes coolant through the supply side of the engine cooling system
• Helps maintain correct coolant flow and operating temperature
• Connects specified cooling system components where fitted
• Helps prevent coolant loss when correctly sealed and installed
• Replaces a cracked, swollen, leaking or heat-damaged original hose
• Provides correct OE Porsche hose shape, material and connection fitment
• Supports reliable cooling system operation.

Why Replace This Part?
Coolant hoses are exposed to heat cycles, coolant pressure, engine bay temperatures, vibration and age-related rubber deterioration. Over time, the hose can harden, swell, crack, split or leak. A failing coolant supply hose may cause coolant loss, low coolant warnings, overheating risk or visible coolant residue around the hose connections.

Replacing it with an OE Genuine Porsche water coolant supply hose helps restore the correct factory coolant routing and reliable cooling system sealing.

Common Symptoms of a Faulty Coolant Supply Hose
•  Coolant leak from the hose or hose connections
•  Dried coolant residue around the cooling system
•  Low coolant warning
•  Coolant smell from the engine bay
•  Engine temperature rising above normal
•  Hose swelling, cracking or softening
•  Coolant pressure loss
•  Damage found during cooling system inspection.

When to Replace This Part
•  If the original coolant hose is cracked, swollen, leaking or damaged
•  During cooling system overhaul
•  When replacing related coolant pipes, water pump, thermostat or radiator components
•  If coolant loss is traced to this hose
•  After engine bay service where the hose has been disturbed
•  If the hose has become brittle or oil-contaminated
•  During preventative maintenance on older cooling systems
•  When restoring the cooling system with OE Genuine Porsche parts.

Where It Fits on the Car
This hose fits in the engine cooling / water cooling system of the Porsche 997. It is identified as a supply-side coolant hose and is shown in Porsche cooling diagrams as diagram reference no. 17.

 Correct routing, clamp positioning and sealing are important to prevent coolant leaks and maintain proper cooling system operation.



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99710674006

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Water coolant hose, supply
OE Match coolant supply hose for selected Porsche 997.1 and 997.2 models. This replacement carries coolant along the supply circuit and provides an alternative to the original Porsche component.

Fits:
Porsche 997.1 2005 - 2008
Porsche 997.2 2009 - 2012

Diagram ref no 17

What This Product Does

The hose joins designated connections within the water-cooling supply circuit. Its role is to carry coolant between those connections, supporting circulation and temperature management. OE Match develops replacement components around Porsche applications, with specification review and sample evaluation forming part of its approval process.

Functions

• Carries coolant along the designated supply route.
• Links the relevant cooling-circuit connections.
• Supports a sealed fluid path when properly fitted.

Technical Details

• Brand: OE Match
• Component: coolant supply hose.
• Supplied part reference: 99710674006
• Additional catalogue references: 99710674004 and 99710674005.

Symptoms of Fault

• Wetness or seepage at either connection.
• A falling coolant level or dashboard level alert.
• A sweet smell or deposits near the hose.
• Temperature readings higher than usual.
• Bulging, splits, hardened areas or unusually soft sections.
• Gurgling associated with low coolant or trapped air.

Why Replacement Matters

Repeated heating and cooling, pressure, vibration and contamination can weaken a hose over time. Renew it when inspection confirms deterioration or identifies it as the leak source. A small seep can develop into substantial fluid loss, so investigate recurring level drops rather than relying on repeated top-ups.

During related cooling repairs, inspect adjoining pipes, fittings, retainers and seals. Check the hose routing and connection security, then refill and bleed according to the vehicle-specific procedure.

FAQs

How should a suspected leak be confirmed?
A cooling-system pressure test and inspection of the hose connections can help distinguish hose leakage from nearby component faults.

Can coolant collect without leaving a puddle?
Yes. Fluid may collect on an undertray or evaporate, leaving deposits rather than obvious drips.

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99710674006

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Water coolant pipe, return.

Fits:
Porsche 996 turbo - 2000 to 2005
Porsche 996 GT3 - 1999 to 2005
Porsche 997.1 turbo - 2007 to 2008

Click 'Zoom in' for large parts diagram.
Diagram ref no 6

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99610632272

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Water coolant pipe, Supply.

Fits:
Porsche 996 turbo - 2000 to 2005
Porsche 996 GT3 - 1999 to 2005
Porsche 997.1 turbo - 2007 to 2008

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

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99610631272

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Water Coolant Pipe, Supply.

Fits:
Porsche 997.1 2005-08
Porsche 997.2 2009-12

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Diagram ref no 1

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99710661032

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Water Hose Return Line. 

The Porsche Water Hose Return Line 99610682204 is a genuine Porsche replacement coolant hose used within the engine cooling circuit on selected Porsche 996 and 997 models.

Fits:

• Porsche 996 C2 3.6L 2002-2005
• Porsche 996 C4 3.6L 2002-2005
• Porsche 996 C4S 3.6L 2002-2005
• 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 33

The hose forms part of the coolant return side of the system, carrying coolant back through the cooling circuit after it has passed through associated engine, radiator or heating-system components.

Maintaining this hose in good condition is essential because the Porsche cooling system operates under pressure and relies on a completely sealed circuit to maintain stable engine temperature.

This Genuine Porsche replacement provides the correct factory-style dimensions, connections and routing for the intended application.

What This Product Does:
The return hose carries coolant through the return side of the vehicle's liquid-cooling system.

Its main functions include:

• Carrying coolant through the return circuit
• Maintaining continuous coolant circulation
• Helping maintain correct cooling-system pressure
• Returning coolant toward the engine or associated cooling circuit
• Supporting stable engine operating temperature
• Preventing coolant loss when correctly sealed
• Maintaining the original Porsche coolant routing
• Connecting adjoining coolant pipes and cooling-system components

The hose works together with the supply hose, coolant pipes, water pump, thermostat and radiators to maintain controlled coolant circulation.

Symptoms Of Wear Or Failure:
Coolant hoses deteriorate over time because of heat, pressure, vibration and repeated thermal cycling.

Common symptoms include:

• Visible coolant leakage
• Wetness around the hose or connections
• Pink, white or crusty coolant residue
• Falling coolant level
• Frequent coolant top-ups
• Low coolant warning
• Sweet coolant smell
• Cracks in the hose surface
• Hardened or brittle rubber
• Swollen or unusually soft hose sections
• Bulging under pressure
• Damaged hose ends
• Leakage around clamps or joints
• Fluctuating coolant temperature
• Engine running hotter than normal
• Steam or coolant vapour after driving
• Engine overheating

A small leak may only appear when the engine is fully warm and the cooling system is pressurised.

Why Replacement Matters:
A deteriorated coolant return hose can fail gradually through seepage or suddenly through a split or rupture.

Loss of coolant can quickly compromise the engine's ability to control temperature.

Continued driving with a leaking hose can result in:

• Cooling-system pressure loss
• Reduced coolant circulation
• Air entering the cooling system
• Engine overheating
• Poor heater performance
• Coolant warning messages
• Roadside breakdown
• Serious engine damage if overheating is allowed to continue

Replacing a worn hose helps restore a sealed cooling circuit and reliable coolant circulation.

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99610682204

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