Coolant Hoses - Radiator Section
- Porsche 996 C4S 3.6L 09/01-2005

Fits:
Porsche 996 C4S Manual Cars
Kits comes water radiator supply and return hoses, breather pipes and all clips and clamps needed.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
WATERPIPEKIT996C4S
The product you are viewing cross references to these numbers
This kit is comprised of the following items:
- Porsche 996 C4S 3.6L 09/01-2005

Fits:
Porsche 996 C4S 2002-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 11
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610613
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- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05

Fits:
Porsche 996 C4S 2002>> Manual
Porsche 997 Turbo Manual
This product supersedes Porsche's old part numbers:
- 99610662677
Click picture for large parts diagram.
Diagram Ref No 9.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610662678
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- 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 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>

Fits:
Porsche 996 C2 / C4 1998-05 TIPTRONIC
Porsche 996 C4S 1998-05 TIPTRONIC
Porsche 996 GT3 1998-05
Porsche 986 Boxster S 3.2L 1997-04
This product supersedes Porsche's old part numbers:
- 99610666651
- 99610666652
- 99610666655
Click 'Zoom in' for large parts diagram.
Diagram Ref No 9.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610666656
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- 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 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>

Fits:
Porsche 996 C2 / C4 1998-05 TIPTRONIC
Porsche 996 C4S 1998-05 TIPTRONIC
Porsche 996 GT3 1998-05
Porsche 986 Boxster S 3.2L 1997-04
This product supersedes Porsche's old part numbers:
- 99610666651
- 99610666652
- 99610666655
Click 'Zoom in' for large parts diagram.
Diagram Ref No 9.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610666656
The product you are viewing cross references to these numbers
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05

Fits:
Porsche 996 C4S 2002>>
Porsche 996 Turbo
This product supersedes Porsche's old part numbers:
- 99610662574
- 99610662578
Click pictrue for large parts diagram.
Diagram Ref No 12.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610662579
The product you are viewing cross references to these numbers
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
Genuine Porsche Upper radiator coolant hose - part of the core engine cooling system that moves radiator coolant effectively between components.
Sold each, Fits left or right side.
Fits:
Porsche 996 C4S 2002 - 2005
Porsche 996 Turbo 2001 - 2005
This product supersedes Porsche's old part numbers: 99610662174, 99610662178
Diagram Ref No 11.
The radiator coolant hose plays a vital role in the engine cooling system by transporting hot coolant from the engine to the radiator and returning cooled coolant back to the engine. This circulation helps regulate operating temperature, ensuring the engine stays within its optimal thermal range and preventing overheating during normal driving conditions.
Installed as part of the upper radiator hose system, the 99610662179:
• Transfers coolant between the radiator and engine cooling passages
• Helps maintain proper engine temperature control
• Supports consistent engine performance and longevity
• Uses durable rubber and reinforcement to withstand high heat, pressure, and vibration.
Replace this hose if you notice:
• Coolant leaks or wetness around the hose ends
• Cracks, bulges, or soft spots in the hose material
• Overheating or fluctuating engine temperatures
• During a cooling system overhaul or replacement of related hardware
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610662179
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- 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

Fits:
Porsche 996 C2 / C4 1998-05
Porsche 996 C4S 1998-05
Porsche 986 Boxster S 3.2L 1997-04
This product supersedes Porsche's old part numbers:
- 99610662252
- 99610662254
Click 'Zoom in' for large parts diagram.
Diagram Ref No 8.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610662255
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- 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

Fits:
Porsche 996 C2 / C4 1998-05
Porsche 996 C4S 1998-05
Porsche 986 Boxster S 3.2L 1997-04
This product supersedes Porsche's old part numbers:
- 99610662252
- 99610662254
Click pictrue for large parts diagram.
Diagram Ref No 8.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610662255
The product you are viewing cross references to these numbers
-
water cooling - 1 - for 996 CARRERA 2/4/4S M96.01/02/03/04 1998-05 105-05
-
water cooling - 2 - for 996 CARRERA M339 (all-wheel drive) M96.01/02/03/04 1998-05 105-12
-
water cooling - 3 - for 996 CARRERA 2/4/4S M96.01/02/03/04 1998-05 105-15
-
air injection 996 CARRERA 2/4/4S M96.01/02/03/04 1998-05 108-05
-
tiptronic atf cooler, atf lines 996 CARRERA 2/4 (M338/M339) A96.00/30 UPTO 2001 360-00
Radiator Section Coolant Hoses – Mid & Rear-Engine Porsche Models
Radiator section coolant hoses are essential for managing engine temperature in mid and rear-engine Porsche models. These hoses circulate coolant between the engine and the radiator, ensuring consistent temperature control and preventing overheating under high-performance conditions.
At Design911, we stock a full range of genuine and manufacturer-quality radiator section coolant hoses specifically designed for mid- and rear-engine Porsche models such as the 911, Boxster, and Cayman. Each hose is built to factory specifications for perfect fitment, superior pressure tolerance, and reliable cooling system performance — ensuring your Porsche operates safely and efficiently on road or track.
What Do Radiator Section Coolant Hoses Do?
In Porsche’s mid- and rear-engine designs, coolant must
travel a greater distance between the engine (located at the rear or middle)
and the radiator (at the front). The radiator section hoses form part of
this vital network, helping to:
- Transport
coolant efficiently from the engine to the front radiator.
- Maintain
optimal engine operating temperature for performance and longevity.
- Regulate
coolant flow through the entire system under varying loads.
- Ensure consistent pressure and leak-free circulation.
These hoses are engineered to handle high thermal and mechanical stress, ensuring reliability even in extreme driving conditions.
Why Do Radiator Coolant Hoses Fail?
Due to their exposure to heat, pressure, and constant
coolant flow, radiator section hoses can wear out over time. Common causes of
failure include:
- Material
fatigue from heat cycles and pressure changes.
- Cracks
or splits in aging rubber or plastic connectors.
- Corrosion
or leaks around hose clamps and fittings.
- Swelling
or softening from prolonged coolant exposure.
- Abrasion damage from rubbing against engine or chassis parts.
Symptoms of a failing coolant hose may include coolant leaks under the car, overheating, fluctuating temperature readings, or a low coolant warning light.
Why Replace Faulty Radiator Section Hoses?
A worn or leaking hose can cause coolant loss, overheating, and potential engine damage. Replacing aging hoses is an essential part of preventative maintenance — especially in mid- and rear-engine Porsche models, where efficient cooling is critical.
Benefits of replacement include:
- Restored, leak-free coolant circulation.
- Improved temperature control and system pressure.
- Prevention of costly overheating and engine damage.
- Manufacturer-quality materials for long-term reliability.
All replacement hoses in this range are constructed using reinforced, high-performance rubber compounds and precision-moulded fittings, ensuring durability, flexibility, and perfect compatibility with Porsche cooling systems.