Parts for your 2000 Mitsubishi Pajero-Thermostat

2000 Mitsubishi Pajero Thermostat — Purpose, care and when to swap it out

Based on Mitsubishi’s workshop manuals (Group 14: Cooling System) for the 1999–2002 Pajero/Montero/Shogun and the Mitsubishi ASA/EPC parts catalogue for the same model years, the 2000 Mitsubishi Pajero is fitted with a conventional wax‑pellet engine thermostat. It’s listed as a service part for both the petrol V6 (e.g., 6G74) and the 3.2 Di‑D diesel (4M41), sitting in the water outlet housing connected to the lower radiator hose. So yes, a thermostat is absolutely used on this vehicle.

This thermostat is the quiet achiever in a 2000 Pajero’s cooling system. It keeps the engine in the sweet spot by staying closed while the donk warms up, then opening at a set temperature (typically in the 76–82°C range depending on engine/market) to let coolant flow through the radiator. That steady operating temp means smoother running, better fuel economy, solid heater performance on cold mornings, and less wear and tear overall.

For servicing, it’s smart to treat the thermostat as part of the cooling system package. If the Pajero is slow to warm up, runs cool on the open road, overheats in traffic, or the temp gauge swings around, the thermostat is a usual suspect. Many owners replace it preventatively when doing a major coolant service, a water pump, or a radiator replacement—especially on higher‑kilometre rigs.

When replacing, go for a quality unit that matches the factory spec and temperature rating for the exact engine code. Always fit a new O‑ring/gasket, clean the housing faces, and tighten the housing bolts to the workshop manual spec. While you’re there, inspect hoses, clamps and the radiator cap, and refresh the coolant with the correct type and mix recommended by Mitsubishi.

Bleeding is important: set the heater to HOT, fill slowly, start the engine with the cap off, squeeze the upper hose to burp bubbles, and top up as the thermostat opens and the level drops. After a proper warm‑up and a short drive, recheck the coolant level in the radiator and overflow bottle.

Keeping the thermostat and coolant in top nick helps protect the alloy heads, avoids hot‑spotting on long tows, and keeps that Pajero happy whether it’s slogging through the High Country or cruising to the shops.

• Typical failure signs: slow warm‑up, weak cabin heat, overheating, fluctuating gauge, or high fan activity.
• Good practice: new gasket/O‑ring, correct coolant, careful bleed, and a post‑service leak check.

Popular questions about 2000 Mitsubishi Pajero thermostats

Where is the thermostat on a 2000 Pajero?
On the petrol V6 it’s in the alloy outlet housing at the front of the engine, where the lower radiator hose connects. On the 3.2 Di‑D diesel it’s mounted in the thermostat housing on the side/front of the engine, also at the lower‑hose connection. It’s accessible from under the bonnet with basic hand tools, though space can be tight.

What thermostat temperature rating should it have?
Most 2000 Pajero engines use a thermostat that begins to open around 76–82°C, with the exact rating depending on engine (6G74 V6 vs 4M41 diesel) and market. The correct spec is listed in the Mitsubishi workshop manual and the parts catalogue against the VIN and engine code, so match the replacement to those details.

Do I need special tools or software after replacement?
No programming is needed. A decent socket set, pliers for hose clamps, a torque wrench, and a drain pan will usually do. The critical step is proper bleeding of the cooling system so there’s no trapped air—heater on HOT, slow fill, run to operating temp, top up, then recheck after a drive.