Parts for your 1998 Mitsubishi Pajero-Head gasket

1998 Mitsubishi Pajero head-gasket: what it does and how to look after it

Yes, a head-gasket is absolutely used on the 1998 Mitsubishi Pajero. All common 1998 Pajero engines — the 2.8L turbo-diesel 4M40 and the petrol V6s 6G72 (3.0L) and 6G74 (3.5L) — are built with a cylinder head and a block separated by a head-gasket. This is documented in the Mitsubishi factory workshop manuals for these engines, the Mitsubishi ASA parts catalogue (which lists specific head-gasket part numbers for each), and independent workshop guides such as the Haynes Pajero/Montero/Shogun manuals covering the 1990s models.

On these Pajeros, the head-gasket seals three critical interfaces under the bonnet: it keeps combustion pressure in the cylinders, it separates engine oil galleries from coolant passages, and it maintains coolant flow without leaks. Depending on the engine and revision, Mitsubishi supplied multi‑layer steel (MLS) or composite/laminate gaskets designed to cope with the heat and clamping loads specified in the workshop procedures.

It’s not a routine service item — the head-gasket is intended to last the life of the engine — but its longevity depends on heat control and correct coolant chemistry. The best “maintenance” is preventive:

• Cooling system care: replace coolant at the recommended interval, use the correct Mitsubishi‑approved formulation at the right mix, and keep the radiator, thermostat, hoses, and radiator cap in good nick. A healthy cooling system is the head-gasket’s best mate.
• Watch the gauges: never ignore a rising temp needle. Overheating is the number one head-gasket killer.
• Look for tell‑tales: unexplained coolant loss, pressurised upper hose when cold, sweet‑smelling exhaust, white steam, milky oil under the oil cap, or a misfire on start‑up.

If replacement is needed, follow the official workshop manual for your exact engine. That means the correct bolt tightening sequence and angle, replacing torque‑to‑yield head bolts where specified, checking head and block flatness against the manual’s limits, and pressure‑testing the head (especially on 4M40 diesels). Don’t use sealant on an MLS gasket unless the manual specifically calls for it. It’s wise to have a reputable machine shop skim the head only if it’s out of spec. After reassembly, bleed the cooling system properly and recheck for leaks after a few heat cycles.

Time and cost vary with engine and condition, but it’s typically a full‑day workshop job or more. Using quality gaskets and following the factory specs from the Mitsubishi workshop manual or equivalent professional references pays for itself in reliability across Aussie and Kiwi conditions.

• Popular questions about 1998 Mitsubishi Pajero head-gasket

What are the common symptoms of a failing head-gasket on a 1998 Pajero?
Owners usually notice coolant loss without visible leaks, overheating, white exhaust vapour after warm‑up, a sweet smell from the tailpipe, bubbling in the expansion bottle, milky residue under the oil filler cap, or rough starting. A cooling system pressure test and a combustion leak test (block test) help confirm it.

Which 1998 Pajero engines have a head-gasket?
All of them do. The 2.8L 4M40 turbo‑diesel and the 3.0L 6G72 and 3.5L 6G74 petrol V6s each use a dedicated head-gasket specified in Mitsubishi’s factory manuals and parts catalogues.

Is it safe to drive with a suspected blown head-gasket?
Best not. Continuing to drive can overheat the engine, warp the head, and turn a gasket job into a full rebuild. If it must be moved, keep trips short, carry extra coolant, and monitor the temperature closely — then organise a proper diagnosis and repair.