Air con evaporators & expansion valves
Fits:
Vehicles With Air-Conditioning
Porsche 928 1993-95
Porsche 964 1993-94
Porsche 968 1993-95
Porsche 993 1994-98
Diagram ref. 37.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
92857331100
The product you are viewing cross references to these numbers
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 968 3.0L 1992-94
- Porsche 968 Sport 3.0L 1994-95
- Porsche 968 CS 3.0L 1993-95
- Porsche 968 Turbo S 3.0L 1993-94
- Porsche 928GTS 5.4L 1992-95
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Restore the rear cabin air-conditioning performance on your Porsche 928 with this genuine evaporator unit (Part # 928 570 211 00). Designed for vehicles with the “Improved Efficiency” A/C option (M570) from around 1985 onwards, this direct-fit part replaces the original rear evaporator core and ensures proper cooling, airflow and de-humidification for the rear passenger compartment.
NOTE: LAST ONE IN STOCK
Fits:
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
Diagram Ref No 19
What This Product Does:
- The evaporator is the component in the A/C system where the refrigerant enters the unit as a low-pressure liquid and absorbs heat from the cabin air, thereby cooling and de-humidifying the air that blows out to the cabin.
- In the rear A/C system of the 928, the evaporator is mounted within the rear HVAC housing and cools the air blowing into the rear passenger compartment.
- A properly functioning evaporator ensures the rear A/C system will deliver cold air, maintain correct charges of refrigerant, and operate efficiently.
- Since the 928’s air conditioning is sometimes used for extended periods (especially in warmer climates), the evaporator must be free of corrosion/leaks, have clean fins, and maintain proper airflow.
Symptoms Of Wear, Failure Or Need For Replacement:
- The rear A/C is not blowing cold, or takes much longer than usual to cool.
- Ice or frost formation on the evaporator core or housing — indicating restricted airflow or super-cooling.
- Leaking refrigerant: a crack or corrosion in the evaporator can cause refrigerant loss, evidenced by reduced cooling, a hissing noise, or oily residue in the HVAC box.
- Poor airflow or musty smell: a clogged, corroded or leaking evaporator may reduce airflow to the rear seats or cause musty odours from mold/moisture accumulation.
- Uneven temperature between front and rear zones (if applicable) — the rear section may lag or not reach set temperature.
- On inspection: visible corrosion, damaged fins, or signs of leaks around the evaporator housing, especially with older vehicles.
Why Replacement Matters:
- A failing evaporator not only reduces comfort (especially for rear passengers), but can lead to higher operating costs, increased wear on the compressor (due to low refrigerant charge or restricted flow), and potential damage to other components (such as blower motors, seals).
- For the 928, which is now a classic car, maintaining a fully functional A/C system helps preserve vehicle value and usability — especially if the car is driven in warmer climates or used for touring.
- Replacing the evaporator ensures the system remains efficient, prevents recurring refrigerant leaks, avoids breakdowns, and ensures correct integration with the rest of the HVAC system (expansion valves, driers, hoses).
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
92857021100
The product you are viewing cross references to these numbers
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
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12 Month Warranty
Worldwide Delivery
The car air conditioning evaporator plays a key role in the heat exchange process that allows the A/C system to operate effectively.
As outdoor air flows through the evaporator fins, it cools down by transferring its heat to the refrigerant. The cooled air is then directed into the cabin at temperatures ranging from 2°C to 10°C.
While air conditioning is typically associated with cooling, one of its crucial functions is to dehumidify the air. Lowering humidity levels is particularly important in cold weather, as passengers can quickly cause condensation to form on the vehicle’s windows.
As the cabin air passes through the A/C system, moisture condenses on the evaporator fins, removing excess humidity from the air. This collected moisture is drained and discharged underneath the vehicle.
The expansion valve receives the refrigerant in a fully filtered, 100% liquid form and reduces its pressure before it enters the evaporator. This pressure reduction cools the refrigerant, which is then sprayed into the evaporator. In car A/C systems, the expansion valve is always connected to the evaporator.
As a precision component, the expansion valve is complex and sensitive to any contaminants or acids circulating within the air conditioning system. If the valve becomes blocked, it can lead to a significant loss of cooling or potentially damage the compressor, as improper flow regulation may allow liquid refrigerant to reach the compressor.
