Parts for your 1998 Mitsubishi Pajero-Water pump

1998 Mitsubishi Pajero Water Pump — Fitment, Purpose, and Service Tips

Technical references, including the Mitsubishi Pajero/Montero factory workshop manuals (1991–1999), the Mitsubishi ASA parts catalogue, Gates timing component listings, and Haynes Pajero manuals, confirm that every 1998 Mitsubishi Pajero engine variant is fitted with a mechanical water pump. That covers the 3.0L V6 6G72, the 3.5L V6 6G74, and the 2.8L diesel 4M40. On the V6 petrols the pump is driven by the timing belt, while on the 4M40 diesel it’s driven by the accessory belts with the viscous fan attached. So yes, a water pump is absolutely relevant and used on a 1998 Pajero.

On a 1998 Pajero, the water pump’s whole job is to keep coolant flowing through the block, heads, heater core and radiator so the engine sits right in its sweet spot for temperature. That keeps power steady, reduces pinging and hot spots, protects the alloy heads, and makes sure the demister and heater work properly. If the pump gets sloppy or starts leaking, overheating and head gasket grief aren’t far behind.

For the V6s (6G72/6G74), it’s smart practice to replace the water pump at the same time as the timing belt service — typically around 90,000–100,000 kilometres or five years, whichever comes first. Labour overlaps heavily, so doing both at once saves time and hassle. For the 4M40 diesel, the pump is external and driven by accessory belts, it should be inspected each service, replaced if there’s leakage from the weep hole, bearing play, or noise, and many workshops pre-emptively fit a new pump when doing belts, idlers or a cooling system refresh around 150,000–200,000 kilometres.

Good workshop habits make a big difference: always clean the gasket surfaces, fit a new gasket or O-ring, torque bolts properly, and use fresh coolant that meets Mitsubishi specs for alloy engines. A 50/50 mix with demineralised water is the go-to in Australia and New Zealand. Bleeding is crucial — heater on hot, radiator cap off, run until the thermostat opens, and burp the hoses to purge air.

• Tell-tales of a tired pump: coolant crust at the weep hole, a rumbling or squeaking bearing, wobble at the pulley, rising temps at highway speeds, or a sweet coolant smell after parking.
• While in there, check the thermostat, radiator cap, belts, idlers, viscous fan clutch and heater hoses. Using a reputable or genuine pump saves rework.

FAQ: What are the signs the 1998 Pajero water pump is failing?

Common clues include a coolant weep or green/pink crust below the pump, bearing noise, pulley wobble, slow temperature creep on the open road, or a heater that goes cold at idle. Any of these warrant inspection before a summer overheat cooks the head gaskets.

FAQ: Should the pump be replaced with the timing belt on a 1998 Pajero V6?

Yes — the V6 pump is driven by the timing belt, so most workshops replace the pump, belt, tensioner and idlers together at around 90,000–100,000 km. The labour overlaps and it avoids paying twice if the pump starts leaking later.

FAQ: What coolant and capacity does a 1998 Pajero need?

Use quality ethylene glycol coolant suitable for alloy engines, mixed 50/50 with demineralised water. Capacity varies by engine and radiator, but expect roughly 9–11 litres. Always bleed the system properly to avoid air locks.