Parts for your 2005 Nissan Navara-Tx valve

2005 Nissan Navara TX Valve — What it does and how to look after it

For the 2005 Nissan Navara (both late D22 and early D40 models), a thermostatic expansion valve (TX valve/TXV) is fitted to the air-conditioning system at the evaporator inlet. This is confirmed by the Nissan factory service manuals (Heating & Air Conditioning “HA” sections for D22/D40, 2005), the Nissan Electronic Parts Catalogue listings that show an “Expansion Valve Assy” for 2005 Navara variants, and independent workshop data sources such as Autodata A/C technical specifications. Typical system layouts shown by Denso/Sanden documentation for these models also depict a TXV with a receiver–drier, not an orifice-tube/accumulator setup.

The TX valve’s job is to meter the flow of R134a refrigerant into the evaporator based on temperature feedback from its sensing bulb, keeping evaporator “superheat” in the sweet spot. That lets the Navara’s A/C pull strong, stable cabin temps without flooding the compressor with liquid refrigerant. In real-world Aussie and Kiwi conditions—idling in summer traffic, towing the boat, crawling a job site—the TXV helps keep cool air consistent and prevents evaporator icing and compressor grief.

As part of routine servicing, the TX valve isn’t a periodic replacement item, but it does deserve attention when diagnosing weak or erratic cooling. Classic TXV clues include warm air at idle then over-chill on the move, frost or sweating on the suction line, a rapid hiss at the expansion block, or odd high/low gauge readings despite the correct charge. When a replacement is needed, it’s a dash-side job because the TXV bolts to the evaporator unit behind the glovebox area on these Navaras. Best practice is to have a licensed A/C tech recover the refrigerant, replace the receiver–drier, renew all O-rings, and add the correct PAG oil type and quantity shown on the under-bonnet label. After refit, the system should be evacuated, leak-tested with nitrogen and dye as required, then recharged by weight with R134a.

• Replace the receiver–drier whenever the system is opened, especially if the TXV has been stuck or contaminated.
• If the compressor has failed or sent debris through the lines, request a full flush and suction screen inspection before fitting a new TXV.
• Use new, compatible O-rings and torque the TXV fittings to spec to avoid leaks and distorted seats.
• Only licensed technicians should handle refrigerant in AU/NZ due to legal and safety requirements.

Looked after properly, the TX valve helps the 2005 Navara’s A/C stay frosty on the hottest days, with fewer surprises and longer compressor life.

Popular questions about the 2005 Nissan Navara TX valve

Where is the TX valve on a 2005 Navara?
The TXV is mounted on the evaporator assembly, behind the passenger-side dashboard near the glovebox. The refrigerant pipes pass through the firewall, disconnecting them there allows the evaporator/TXV unit to be removed for access.

What are the signs of a faulty TX valve?
Inconsistent cooling, evaporator or suction-line icing, higher-than-normal high-side pressures with starved low-side readings, or a sharp hissing at the expansion block can all point to a sticking or restricted TXV. Proper diagnosis with gauges and temperature probes is recommended.

Should the drier be replaced when changing the TX valve?
Yes. Any time the system is opened, the receiver–drier should be renewed to protect the new TXV and the compressor from moisture and contaminants, and to maintain correct system performance.