Parts for your 2000 Nissan Navara-Thermostat housing

2000 Nissan Navara Thermostat Housing — What It Does and How to Look After It

Based on the Nissan Navara D22 factory service manual (Cooling System “CO” section) and Nissan FAST parts catalog diagrams for the 2000 D22 range (KA24 petrol and QD32/ZD30 diesel engines), the 2000 Nissan Navara is fitted with a thermostat housing (often listed as the water outlet/thermostat cover). It bolts to the cylinder head, holds the thermostat in place, and connects to the upper radiator hose—so it’s absolutely relevant on this model.

On a 2000 Navara, the thermostat housing’s job is to seal and locate the thermostat, direct coolant flow to the radiator, and provide a leak-free connection to the hose. When the engine’s cold, the thermostat stays shut so the motor warms up quickly. As it reaches operating temp, the thermostat opens and the housing channels hot coolant to the radiator. A healthy housing is key to stable temps, decent heater performance, and protecting the engine from overheating under load.

During regular servicing, it’s smart to give the thermostat housing a once-over. Look for dried coolant trails, pink/green crusting, or hairline cracks around the hose neck and bolt ears. Any seepage around the gasket/O-ring means it’s time to reseal. If the plastic or alloy casting is pitted or warped, replacement is the go-to fix rather than trying to nurse it along.

Replacing the housing (or just the thermostat and seal) is a straightforward driveway job for most owners:

• Work on a cool engine, drain enough coolant to drop the level below the housing.
• Remove the upper hose, then the housing bolts. Note the thermostat orientation.
• Clean both mating faces carefully—no gouges—then fit a new thermostat and O-ring/gasket.
• Refit the housing and tighten bolts evenly to factory spec (commonly around 12–16 N·m on D22 engines—check the service manual for your exact engine).
• Refill with the correct coolant mix, bleed the system with the heater on hot, and check for leaks.

If the old hose neck is corroded, throw on a new hose and clamp while you’re there. Sticking with a quality housing and thermostat that match the D22 spec helps avoid slow warm-up, overcooling on the open road, or annoying leaks under the bonnet.

Popular questions

Where is the thermostat housing on a 2000 Navara?
On D22 models it sits at the front/side of the engine where the upper radiator hose meets the engine. It’s the small alloy or composite outlet bolted to the head, holding the thermostat inside. Access is typically under the bonnet from the top