Parts for your 2015 Audi Q5-Tx valve

2015 Audi Q5 TX Valve — What It Does and When to Service It

Referencing Audi’s factory service information (ElsaWin/erWin) for the 2015 Q5 (type 8R) and the OEM parts catalogue (ETKA), this model’s climate-control system is built around a thermostatic expansion valve (TXV) at the evaporator. Genuine parts listings identify an expansion valve commonly noted as Audi p/n 8K0 260 499 (with possible supersessions by VIN). Technical HVAC diagrams for the Q5 show the valve regulating flow into the evaporator rather than a fixed orifice tube. So yes, a TX valve is absolutely relevant and fitted to the 2015 Audi Q5.

The TX valve’s job is to meter refrigerant into the evaporator based on temperature and pressure, maintaining the right superheat so the air-con stays cold without flooding the compressor. By matching refrigerant flow to heat load, it helps keep vent temps stable in Aussie and Kiwi conditions—whether it’s a hot run up the motorway or stop–start city traffic.

It isn’t a routine “wear” item, but it can fail or get contaminated by debris or moisture. Typical signs include weak cooling at idle that improves on the open road, evaporator icing, fluctuating vent temps, or pressure readings that swing about. On vehicles with diagnostics, HVAC fault memories can also hint at flow or temp control issues.

Replacement is straightforward for a licensed air-con technician but not a DIY driveway task. The system must be safely recovered, lines cracked at the valve, and O-rings renewed. On the Q5, the TXV is located at the evaporator near the firewall/plenum, access often involves removing trims in the plenum/wiper cowl area. Best practice during TXV replacement includes:

• Recovering refrigerant (R134a or R1234yf depending on market—check the under-bonnet label).
• Flushing lines if contamination is suspected, and replacing the receiver–drier/desiccant (often part of the condenser) whenever the system is opened.
• Using the correct PAG oil type/quantity and new green HNBR O-rings.
• Evacuating, vacuum-holding, and then recharging by weight to spec, followed by a leak test (nitrogen/trace gas or UV dye as appropriate).

Because refrigerant handling is regulated (ARCtick in Australia, licensed technicians in NZ), it’s smart to book a qualified workshop. They’ll confirm pressures and temperatures, check for blend-door or sensor faults that can mimic a sticking TXV, and ensure the Q5’s air-con is sorted for the long haul.

Does the 2015 Audi Q5 use a TX valve or an orifice tube?

It uses a thermostatic expansion valve. Audi’s service manuals and the ETKA parts catalogue show a TXV mounted at the evaporator on the 2015 Q5 (type 8R), not a fixed orifice tube.

What are the common symptoms of a failing TX valve on a Q5?

Expect poor cooling at idle that improves at speed, evaporator icing, inconsistent vent temperatures, and odd pressure readings during gauge checks. A contaminated system can also leave the TXV stuck or restricted.

Do you need to re-gas after replacing the TX valve, and how much refrigerant goes in?

Yes—any time the system is opened, it must be evacuated and recharged by weight. The exact refrigerant type and charge quantity are on the Q5’s under-bonnet label, and a licensed air-con technician will fill it to spec.