Parts for your 1998 Nissan Navara-Tx valve

1998 Nissan Navara TX Valve: What It Does, Where It Lives, and When to Replace It

Based on technical sources, the 1998 Nissan Navara (D22) is fitted with a thermostatic expansion valve (TX valve/TXV). The Nissan D22 Factory Service Manual (Heating & Air Conditioning section), Nissan FAST parts catalogue for D22, and common AU/NZ parts catalogues from major A/C suppliers all list a “thermo control valve” (TXV) mounted at the evaporator inlet. So yes—this model uses a TX valve rather than an orifice tube.

The TX valve’s whole job is to meter R134a refrigerant into the evaporator based on temperature at the outlet (via a sensing bulb). That keeps the evaporator cold without flooding it, protects the compressor from liquid slugging, and helps the cabin cool quickly and consistently. When the TXV is doing its thing, the Navara’s A/C holds steady vent temps, even with changing engine speed and ambient conditions.

It’s not a routine service item, but a crook TX valve can cause weak cooling, uneven vent temps, or icing. It’s commonly replaced when the evaporator box is out, or whenever the system’s been contaminated (compressor failure, moisture ingress). When replacing the TXV on a 1998 Navara, a few best-practice tips apply.

• Always recover refrigerant legally (ARCtick-licensed shop in Australia, certified handler in New Zealand). Venting is illegal.
• Replace the receiver-drier/accumulator and O-rings, and add the correct PAG oil amount for parts changed.
• Flush lines (except the compressor and TXV) if there’s debris, and fit an inline filter if contamination is suspected.
• Pull a deep vacuum and hold it, then weigh in the charge to the under-bonnet spec. Don’t charge by “feel”.
• Pressure-test with nitrogen and leak-check with an electronic detector and UV dye as needed.

On the D22 Navara, the TX valve sits at the evaporator inlet on/through the firewall—accessible from inside behind the glovebox once the evaporator case is opened up, and visible in the engine bay where the two A/C pipes meet the case. Technicians will check superheat, pressures, and temperature split across the evaporator to confirm TXV performance. If it’s stuck shut you’ll see starved evaporator symptoms (high superheat, low suction, poor cooling), stuck open or contaminated and you may get icing, low superheat, and erratic vent temps.

Bottom line: the TX valve is a key piece of the Navara’s A/C reliability. If cooling’s gone walkabout, proper diagnosis beats guesswork, and replacement should follow OEM procedures noted in the D22 FSM.

Popular questions about 1998 Nissan Navara TX valves

Does the 1998 Navara use a TX valve or an orifice tube?
It uses a thermostatic expansion valve. This is documented in the D22 Factory Service Manual and parts catalogues listing a “thermo control valve” at the evaporator. An orifice tube isn’t used on this model.

Where is the TX valve located on a 1998 Navara?
It’s mounted at the evaporator inlet on the passenger side. Access is typically from inside the cabin behind the glovebox by opening the evaporator case, with the line connections visible at the firewall in the engine bay.

What does it usually cost to replace a TX valve?
Parts are often in the $80–$200 range, with 2–4 hours of labour plus refrigerant and consumables. That puts typical workshop totals around AUD $400–$900 or NZD $450–$1,000, depending on access, contamination, and whether the receiver-drier and other bits are done at the same time.