Parts for your 1989 Mitsubishi Pajero-Head gasket

1989 Mitsubishi Pajero head gasket — what it does and how to look after it

Technical sources confirm the 1989 Mitsubishi Pajero absolutely uses a cylinder head gasket. The Mitsubishi Pajero/Montero Factory Service Manual (1983–1991), Gregory’s Service and Repair Manual for Pajero, Haynes Pajero/Montero/Shogun (1983–1991), and the Mitsubishi ASA parts catalogue all list a head gasket for the 4D56 2.5 turbo-diesel, 4G54 2.6 petrol, and 6G72 3.0 V6 engines fitted in 1989. So yes—this part is relevant to every 1989 Pajero variant.

On these engines, the head gasket seals the join between the cylinder head and the engine block. It keeps combustion pressure in, while keeping oil and coolant in their own lanes. That tight seal stops cross-contamination, keeps compression healthy, and helps the cooling system do its job. Materials vary by engine and supplier—composite and multi-layer steel (MLS) gaskets are both common—but the job is the same: hold pressure and fluids under serious heat cycles.

It’s not a routine “service item,” but it’s critical. Overheating is the big killer, especially on 4D56 diesels. Keeping the cooling system in top nick massively reduces head gasket drama. That means fresh coolant, a radiator that actually flows, a thermostat that opens on time, and a viscous fan or electric fans that pull enough air.

• Typical failure clues: unexplained coolant loss, pressurised hoses from cold, white exhaust steam, sweet smell in the exhaust, milky oil, misfire on start-up, or overheating under load.

1. Diagnose properly: chemical block test, cooling system pressure test, and compression/leak-down. Don’t tear in on a hunch.
2. Cooling system first: fix the root cause of any overheat before the new gasket goes in.
3. Machine and measure: check the head for cracks and warpage