Parts for your 2018 Volkswagen Amarok-Tx valve

2018 Volkswagen Amarok TX‑valve: what it does and how to look after it

Based on Volkswagen factory information and parts catalogues, the 2018 Volkswagen Amarok (2H) uses a thermal expansion valve (TX‑valve) in its air‑conditioning system. This is shown in Volkswagen’s official repair literature for Amarok heating and air conditioning, and in the VW ETKA parts catalogue for model 2H, where an expansion valve is listed at the evaporator inlet. Independent technical guides from major A/C component suppliers also describe the Amarok’s front A/C system as a TX‑valve type rather than an orifice‑tube design.

On the Amarok, the TX‑valve meters refrigerant into the evaporator based on temperature and pressure (superheat). That keeps cabin temps steady, improves cooling at idle and in stop‑start traffic, and protects the compressor from liquid slugging. It pairs well with the Amarok’s variable‑displacement compressor to deliver smooth, efficient cooling on hot Aussie and Kiwi summer days. Most 2018 AU/NZ models run R134a, some markets moved to R1234yf—either way, the TX‑valve’s job stays the same.

The valve is typically mounted at the evaporator inlet where the A/C lines enter the HVAC box at the firewall. It isn’t a routine service item, but it does benefit from system‑wide care. If cabin cooling is weak or erratic, the evaporator ices up, or pressures and vent temps swing around, the TX‑valve could be sticking or restricted.

• Common signs: poor cooling at idle or cruise, rapid compressor cycling, hissing at the dash, frost on lines, or uneven vent temps.
• Good habits: keep the cabin filter fresh and the condenser clean to reduce system strain, run the A/C regularly to keep seals and internals lubricated.

Replacement or diagnosis should be handled by a licensed ARCtick technician. Opening the A/C circuit requires safe recovery of refrigerant, new O‑rings, and a vacuum/charge to the label‑specified weight. It’s smart practice to replace the receiver‑drier (often integrated with the condenser or as a service cartridge) when the system is opened, add the correct compressor oil balance, nitrogen‑pressure test for leaks, then evacuate for 30+ minutes before re‑gassing. Correct line torque and cleanliness are critical to avoid future leaks and moisture ingress.

Technical sources referenced: Volkswagen Amarok (2H) factory repair information for Heating/Air Conditioning, Volkswagen ETKA parts catalogue (Model 2H, A/C group) listing an expansion valve, and supplier technical briefs on TX‑valve‑type VAG A/C systems.

FAQs

Where is the TX‑valve on a 2018 Amarok?

It’s typically fitted at the evaporator inlet, right where the two A/C pipes pass through the firewall into the HVAC box on the passenger side. Access may require moving adjacent components to reach the fittings cleanly.

What are the symptoms of a failing TX‑valve on an Amarok?

Expect weak or fluctuating cooling, evaporator icing, rapid compressor cycling, or noticeable hissing near the dash. On gauges, you may see unstable pressures and either very high or very low superheat.

Do you need to regas after replacing the TX‑valve?

Yes. The system must be recovered, opened, sealed with new O‑rings, vacuumed, and recharged to the factory‑specified weight. A licensed A/C technician should also leak‑test and consider replacing the receiver‑drier when the circuit has been opened.