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Coolant Hoses - Engine Bay
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
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99970741040
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
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 / GT3 RS 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche 997 MKII GT3 / GT3 RS 2010-11
- Porsche Carrera GT 2003-06
Shop Securely
12 Month Warranty
Worldwide Delivery
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
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99970741040
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
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 / GT3 RS 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche 997 MKII GT3 / GT3 RS 2010-11
- Porsche Carrera GT 2003-06
Shop Securely
12 Month Warranty
Worldwide Delivery
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.
Monday-Friday: 8.30am - 5.30pm (GMT)
Saturday: Closed
Sunday: Closed