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Air con evaporators & expansion valves
This precision valve regulates the flow of refrigerant into the evaporator, ensuring efficient cooling and stable climate control inside the vehicle. Manufactured to Porsche’s original equipment standards, the expansion valve provides the correct pressure control and refrigerant flow required for reliable air conditioning performance and optimal cabin comfort.
Fits:
Porsche 986 Boxster 1997 - 2004
Porsche 987 Boxster 2005 - 2008
Porsche 987C.1 Cayman 2005 - 2008
Porsche 987C.2 Cayman 2009 - 2013
Porsche 996 1998 - 2005
Porsche 997.1 2005 - 2008
Diagram ref no 4
The expansion valve meters and controls the amount of refrigerant entering the air conditioning evaporator. It reduces the pressure of the refrigerant as it enters the evaporator, allowing it to expand and cool rapidly. This process absorbs heat from the cabin air and produces the cold air delivered through the ventilation system.
The expansion valve works together with the compressor, condenser, and evaporator to maintain efficient cooling performance and balanced refrigerant pressure throughout the system.
Functions & Technical Role
• Refrigerant regulation: Controls the flow of refrigerant into the evaporator
• Pressure reduction: Converts high-pressure liquid refrigerant into a low-pressure mixture for cooling
• Temperature control: Maintains consistent cooling performance in the HVAC system
• System protection: Prevents excess refrigerant from entering the evaporator
• OEM precision: Designed to Porsche specifications for correct installation and reliable operation
Fitment / Position on Car
• Fitting position: Air conditioning system
• Location: Mounted next to the evaporator within the HVAC housing
• System: Climate control / refrigerant distribution system
The expansion valve operates under constant temperature changes and refrigerant pressure, and can wear or become blocked over time. A faulty valve may lead to:
• Weak or inconsistent air conditioning performance
• Evaporator icing or insufficient cooling
• Increased system pressure or compressor strain
• Noisy or inefficient HVAC operation
Replacing a worn valve with a genuine Porsche OE component restores proper refrigerant control and ensures the air conditioning system performs as designed.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99657392901
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- 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 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 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
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12
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12 Month Warranty
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The expansion valve is located within the air conditioning evaporator housing and acts as a precision regulator for refrigerant flow. It reduces the pressure of the refrigerant before it enters the evaporator and controls the amount of refrigerant that passes through the system.
Fits:
Porsche 986 Boxster 1997 - 2004
Porsche 987 Boxster 2005 - 2008
Porsche 987C.1 Cayman 2005 - 2008
Porsche 987C.2 Cayman 2009 - 2013
Porsche 996 1998 - 2005
Porsche 997.1 2005 - 2008
Diagram ref no 4
This OE Match version matches the original Porsche specifications for size, mounting configuration and flow characteristics. This ensures correct refrigerant pressure regulation and compatibility with the A/C systems used in Porsche 986, 987, 996 and early 997 vehicles.
A properly functioning expansion valve is essential for maintaining consistent cooling performance and preventing irregular cabin temperatures.
The expansion valve controls refrigerant flow into the evaporator by adjusting pressure and volume according to system demand. This allows the refrigerant to expand and cool effectively, enabling the evaporator to remove heat from the cabin air.
If the valve fails or becomes restricted, the air conditioning system may lose cooling efficiency or produce inconsistent temperatures.
Function
• Refrigerant Flow Control: Regulates refrigerant entering the evaporator
• Pressure Regulation: Reduces refrigerant pressure for effective cooling
• Temperature Stability: Helps maintain consistent cabin temperature
• A/C Efficiency: Supports optimal operation of the air conditioning system
Expansion valves can wear or become clogged with debris over time. When the valve fails, refrigerant pressure may not be regulated correctly, leading to poor cooling performance or fluctuating cabin temperatures. Replacing a faulty expansion valve restores proper refrigerant flow and helps maintain efficient air conditioning operation.
When to Replace. Consider replacing the expansion valve if you notice:
• Weak or inconsistent air conditioning cooling
• Refrigerant pressure imbalance in the system
• A/C system repair requiring evaporator removal
• During air conditioning system overhaul or service
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99657392901
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- 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 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 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
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12
Shop Securely
12 Month Warranty
Worldwide Delivery
Porsche Air Conditioning Evaporators & Expansion Valves | Efficient Climate Control & Cooling Precision
The air conditioning evaporator and expansion valve work hand-in-hand to regulate your Porsche’s cabin temperature and cooling performance. The evaporator absorbs heat from the interior air, while the expansion valve controls refrigerant flow and pressure — ensuring optimal cooling efficiency and consistent climate control in all conditions.
At Design911, we supply premium-grade air conditioning evaporators and expansion valves engineered to match or surpass original performance standards. Each component is built from corrosion-resistant aluminium and precision-calibrated materials for maximum reliability, refrigerant control, and long-lasting performance.
Whether you’re restoring your Porsche’s A/C system or repairing poor cooling output, our evaporators and expansion valves guarantee dependable operation and comfort on every drive.
What Do Air Con Evaporators & Expansion Valves Do?
These two critical components form the heart of your Porsche’s A/C cooling system.
Core Functions:
- Evaporator: Cools the cabin by absorbing heat as the refrigerant evaporates.
- Expansion Valve:
Regulates the refrigerant entering the evaporator, maintaining correct
pressure and temperature.
- Ensures steady, efficient cooling in all operating conditions.
- Prevents compressor overload and system freezing.
- Maintains optimal refrigerant balance for comfort and performance.
Why Do Air Con Evaporators & Expansion Valves Fail or Degrade?
These parts operate under constant temperature and pressure fluctuations, making them vulnerable to wear, corrosion, and contamination over time.
Common Causes of Failure Include:
- Corrosion or cracking of the evaporator core.
- Blockage or sticking in the expansion valve from debris.
- Moisture contamination leading to ice build-up inside the system.
- Refrigerant leaks reducing cooling efficiency.
- Age-related deterioration of seals, fins, or fittings.
When these components fail, you may notice weak cooling, fluctuating cabin temperatures, hissing noises, or A/C system fault codes.
Why Replace Your Porsche Air Con Evaporator & Expansion Valve?
Replacing a worn or leaking evaporator and expansion valve restores the A/C system’s ability to maintain stable, efficient cooling. It also prevents costly compressor damage and protects the system from moisture and pressure-related failures.
Key Benefits:
- Restores cold, consistent cabin air flow.
- Prevents refrigerant loss and internal contamination.
- Improves system efficiency and compressor protection.
- Maintains correct refrigerant pressure and flow rate.
- Designed for Porsche 911, Cayman, Boxster, Panamera, Macan, and classic models.
- Ideal for A/C servicing, rebuilds, or performance restoration.
Regular A/C servicing and replacement of worn components ensure long-term comfort, reliability, and system protection.
Highlights
- High-efficiency Porsche A/C evaporators and expansion valves.
- Corrosion-resistant aluminium cores for long-term reliability.
- Precision-engineered for accurate refrigerant flow control.
- Direct-fit designs for Porsche road and performance models.
- Perfect for repairs, restorations, or preventative maintenance.
- Improves cooling performance and system longevity.
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Sunday: Closed