Parts for your 2007 Subaru Impreza-Tx valve

2007 Subaru Impreza TX Valve (Thermal Expansion Valve)

Yes, the 2007 Subaru Impreza uses a thermal expansion valve (often called a TX valve or TXV) in its air-conditioning system. This is supported by Subaru’s Factory Service Manual HVAC section for the 2007 Impreza, which details expansion valve removal and installation at the evaporator, the Subaru FAST electronic parts catalogue listing “VALVE-EXPANSION” for the model year, and DENSO’s component application data for GD/GG Impreza models that specifies a TXV rather than an orifice tube.

The TX valve meters R134a refrigerant into the evaporator based on temperature sensed at the outlet, keeping superheat in the right window. That means steadier cabin temps, better cooling at idle, and protection against liquid slugging the compressor. When the valve sticks, gets blocked with debris or moisture, or the sensing bulb fails, the Impreza can show weak cooling, evaporator icing, hissing at the dash, rapid compressor cycling, or big swings in vent temperature.

As part of regular servicing, a TX valve isn’t a routine replacement item, but it’s smart to inspect whenever the air-con is opened. If the system has been contaminated (for example after a compressor failure), best practice is to replace the TX valve and the receiver–drier, flush what’s flushable, and recharge with clean refrigerant and the correct oil.

• Always have refrigerant recovered and charged by an ARCtick-licensed professional in Australia or a qualified automotive air-con technician in New Zealand.
• Access is typically via the HVAC case behind the glovebox, the TXV mounts at the evaporator pipes. Replace all O-rings (HNBR/green) and lightly oil them with the specified PAG (ND-OIL 8) before assembly.
• Tighten fittings to the Subaru manual’s torque spec to avoid leaks or distorted seats.
• Evacuate (deep vacuum) for at least 30 minutes and verify it holds before charging by weight to the under-bonnet label.
• Fit a new receiver–drier any time the system has been opened to atmosphere.

Prevention helps: keep the cabin filter clean to maintain airflow across the evaporator, clear the condenser of debris, and run the air-con regularly year-round to keep seals lubricated and moisture purged.

• Does a 2007 Subaru Impreza use a TX valve or an orifice tube?
  It uses a TX valve. Subaru’s service manual and parts catalogue list an expansion valve at the evaporator for this model year, not an orifice tube system.

• What are the signs the TX valve is failing on a 2007 Impreza?
  Weak cooling (especially at idle), evaporator or suction line icing, fluctuating vent temps, rapid compressor cycling, and unusual hissing at the dash are common clues. Gauge readings often show abnormally low suction or erratic pressures.

• Should the TX valve be replaced whenever the system is opened?
  Not always. Replace it if there’s contamination, moisture ingress, or a failing compressor has shed debris. Otherwise, inspect, renew O-rings, replace the receiver–drier, vacuum thoroughly, and recharge to spec.