Coolant Hoses - Engine Bay
Fits:
Porsche 996 C2 3.4L Manual
Kits comes with engine bay rubber pipe
Diagram ref: #1, #3, #18, #23, # 24, #27, #33
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
WATERPIPEKIT996C2.34.M
The product you are viewing cross references to these numbers
- Porsche 996 C2 3.4L 1997-08/01
Fits:
Porsche 996 C2 3.6L Manual
Kits comes with engine bay rubber pipe
Diagram ref: #1, #3, #18, #23, # 24, #27, #33
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
WATERPIPEKIT996C2.36.M
The product you are viewing cross references to these numbers
- Porsche 996 C2 3.6L 09/01-2005
Fits:
Porsche 996 C4 3.4L Manual
Kits comes with engine bay rubber pipe
Diagram ref: #1, #3, #18, #23, # 24, #27, #33
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
WATERPIPEKIT996C4.34.M
The product you are viewing cross references to these numbers
- Porsche 996 C4 3.4L 1997-08/01
Fits:
Porsche 996 C4 3.6L Manual
Kits comes with engine bay rubber pipe
Diagram ref: #1, #3, #18, #23, # 24, #27, #33
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
WATERPIPEKIT996C4.36.M
The product you are viewing cross references to these numbers
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005


Fits:
Porsche 996 C4 2002-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 12
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610683603
The product you are viewing cross references to these numbers
- Porsche 996 C4 3.6L 09/01-2005


Fits:
Porsche 996 3.6ltr C2 / C4 / C4S - 2002 to 2005
Click 'Zoom in' for large parts diagram.
Diagram ref no 47
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610685103
The product you are viewing cross references to these numbers
- 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 Turbo 2001-05
Porsche 996 GT2 2002-05
Porsche 996 GT3 2004-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 19
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610647775
The product you are viewing cross references to these numbers
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 RS 2003-04


Fits:
Porsche 996 Turbo / GT2 2001-05
Porsche 996 GT3 1999-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 21
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610652973
The product you are viewing cross references to these numbers
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04


Fits:
Porsche 996 3.4L/3.6L C2 / C4 / C4S 1998-2005
M 66X 01815 >>
Click 'Zoom in' for large parts diagram.
Diagram ref no 29
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610623356
The product you are viewing cross references to these numbers
- 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 3.4L/3.6L C2 / C4 / C4S 1998-2005
M 66X 01815 >>
Click 'Zoom in' for large parts diagram.
Diagram ref no 29
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610623356
The product you are viewing cross references to these numbers
- 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 Turbo / GT2 / GT3 1999>>
This product supersedes Porsche's old part numbers:
- 996 106 501 74
- 996 106 501 76
Click "Zoom in" to see the diagram.
Diagram ref no 15.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610650177
The product you are viewing cross references to these numbers
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04


Fits:
Porsche 996 Turbo / GT2 / GT3 1999>>
This product supersedes Porsche's old part numbers:
- 996 106 502 74
Click "Zoom in" to see the diagram.
Diagram ref no 16.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99710650200
The product you are viewing cross references to these numbers
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04


Fits:
Porsche 996 C4 / C4S 1998-05
All-wheel drive (option code: 339)
Click 'Zoom in' for large parts diagram.
Diagram ref no 11
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610672806
The product you are viewing cross references to these numbers
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
Left Side Return Hose, From right side radiator return pipe to under car return pipe.

Fits:
Porsche 996 C4 / C4S 1998-05
All-wheel drive (option code: 339)
Click 'Zoom in' for large parts diagram.
Diagram ref no 11
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610672806
The product you are viewing cross references to these numbers
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005

From feed pipe.

Fits:
Porsche 996 C2 / C4 / C4S 1998-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 27
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610621260
The product you are viewing cross references to these numbers
- 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
From feed pipe.

Fits:
Porsche 996 C2 / C4 / C4S 1998-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 27
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99610621260
The product you are viewing cross references to these numbers
- 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
Coolant Hoses – Engine Bay | Reliable Cooling for Peak Porsche Performance
Coolant hoses in the engine bay are critical components that circulate coolant between the radiator, water pump, and engine block — maintaining consistent operating temperatures and preventing overheating. These hoses carry coolant through high-pressure, high-temperature zones within the engine bay, ensuring your Porsche performs at its best, even under demanding conditions.
At Design911, we stock a wide range of genuine and manufacturer-quality engine bay coolant hoses for Porsche models including 911, Boxster, Cayman. Each hose is designed to fit perfectly, resist extreme temperatures, and deliver long-lasting performance — matching the quality, precision and reliability.
What Do Engine Bay Coolant Hoses Do?
Coolant hoses form part of your Porsche’s closed-loop
cooling system. Their job is to:
- Circulate
coolant between the engine, radiator, and water pump.
- Maintain
engine temperature for optimal performance and emissions.
- Support
consistent coolant pressure during operation.
- Prevent engine overheating and protect internal components from heat damage.
In high-performance engines, such as those found in Porsche vehicles, properly functioning hoses are essential for ensuring precise temperature control and long-term mechanical integrity.
Why Do Engine Bay Coolant Hoses Fail?
Over time, coolant hoses endure constant exposure to heat,
vibration, and pressure, which can cause wear and eventual failure. Common
causes include:
- Rubber
deterioration from heat cycling and coolant chemicals.
- Cracking
or hardening due to age and environmental factors.
- Swelling
or soft spots from internal coolant corrosion.
- Leaks
at connections caused by weakened hose ends or clamps.
- Abrasion or rubbing against other engine components.
Symptoms of failure include coolant leaks, overheating, fluctuating temperature readings, or a noticeable smell of coolant in the engine bay.
Why Replace Faulty Coolant Hoses?
A damaged or leaking hose can cause rapid coolant loss and severe engine overheating. Replacing worn hoses ensures your Porsche’s cooling system functions reliably and efficiently.
Benefits of replacement include:
- Restored coolant circulation and temperature control.
- Prevention of leaks, overheating, and potential engine damage.
- Improved reliability and performance under all driving conditions.
- Manufacturer-quality construction and perfect fitment.
All hoses in this range are built using reinforced, high-grade rubber compounds designed to withstand extreme heat, pressure, and vibration — ensuring lasting durability and peace of mind.