Parts for your 1986 Mitsubishi Pajero-Coolant

1986 Mitsubishi Pajero Coolant — What It Does and How To Look After It

Coolant is absolutely relevant to the 1986 Mitsubishi Pajero. All factory engines fitted to this model year—such as the 2.6L petrol 4G54 and the 2.3/2.5L diesel family—use a liquid-cooled, pressurised system with a radiator, thermostat, water pump and an ethylene glycol–based coolant. This is documented in Mitsubishi’s Pajero/Montero Factory Service Manual (1983–1991, Cooling System section), the 1986 Owner’s Manual, and widely available workshop guides like the Haynes Repair Manual for 1983–1997 models. So yes, coolant is used, and it’s a key service item on this classic 4x4.

On a 1986 Pajero, coolant does more than stop overheating. Mixed correctly with demineralised water, it raises the boiling point, lowers the freezing point, lubricates the water pump seal, and—most importantly—protects the alloy head, cast-iron block, radiator and heater core from internal corrosion and scale. The system relies on the radiator cap to hold pressure and keep temps in check when you’re crawling up a rutted hill or towing the boat to the ramp.

For an older Mitsubishi of this era, a quality ethylene glycol IAT (traditional green) coolant is the safe pick. Avoid mixing different chemistries like OAT/HOAT unless the product explicitly states backward compatibility. A 50/50 mix with demineralised water works for most Aussie and Kiwi conditions