Parts for your 1987 Mitsubishi Pajero-Water pump

1987 Mitsubishi Pajero water pump — what it does and when to replace it

Based on factory literature and recognised manuals, the 1987 Mitsubishi Pajero does use a mechanical water pump across its petrol and diesel engines. Technical sources that document this include the Mitsubishi Pajero L040/L141 Factory Service Manual (Cooling System section), Mitsubishi Motors ASA electronic parts catalogue listings for 4G54 petrol and 4D55/4D56 diesel engines, and aftermarket guides such as Gregory’s Pajero manual (1983–1996) and Haynes/Max Ellery publications. All describe a belt-driven centrifugal water pump circulating coolant through the block, head, radiator and heater core.

On a first‑gen ’87 Pajero, the water pump is the workhorse of the cooling system. Spinning with the front engine belt drive, it keeps coolant moving so temperatures stay steady whether it’s towing the boat up the Kaimais or crawling a rutted track under the Aussie sun. If the pump slows, leaks or the bearings cry enough, temps climb, heaters go cold at idle, and it can put head gaskets at risk — not a drama anyone wants under the bonnet.

As part of normal servicing, it’s smart to keep an eye on the pump and refresh it at sensible intervals. Many owners pair a new pump with timing/drive belt work because the front of the engine is already apart, saving time and labour. Fresh coolant with the correct corrosion inhibitors for alloy heads, a new thermostat and cap, and a proper bleed make a tidy package that keeps the cooling system healthy for years.

• Watch-for signs: pink/green crust at the weep hole, a sweet coolant smell, play or noise at the pulley, or temps creeping up at low speed.
• Replacement tips: use a quality pump and gasket, clean the mating face carefully, torque bolts evenly, and refill with the specified coolant mix. Burp the system and confirm heater performance.
• Intervals: check the workshop manual for your engine code, many owners opt for replacement around major belt services (roughly 90–100,000 km) or at the first hint of leakage or bearing noise.

For anyone keeping a classic Pajero running sweet, a sound water pump isn’t just nice-to-have — it’s cheap insurance against overheating on long hauls and hard yakka off-road.

Popular questions

Does a 1987 Mitsubishi Pajero actually have a water pump?
Yes. Factory manuals and parts catalogues list a belt-driven centrifugal water pump for the 4G54 petrol and 4D55/4D56 diesel engines used in 1987. It’s an essential part of the liquid-cooling system.

How often should the water pump be replaced on a 1987 Pajero?
There’s no single kilometre figure for every engine, but many owners replace the pump during major front‑of‑engine service (timing/drive belts) or at the first sign of leakage or bearing noise. Checking the service manual for the exact interval on the specific engine code is the safest bet.

What are the signs the water pump is failing?
Look for coolant weeping from the pump body, wobble or rumble at the pulley, rising temps in traffic, or coolant tracks around the housing. A low heater output at idle can also hint at poor circulation.