Parts for your 1998 Mitsubishi Pajero-Spark plugs

1998 Mitsubishi Pajero spark plugs — what’s fitted and what to service

Technical sources including the Mitsubishi Pajero (1991–1999) workshop manual, the 1998 owner’s handbook, and NGK/Denso application catalogues confirm that 1998 Pajero petrol V6 engines (3.0L 6G72 and 3.5L 6G74) are fitted with spark plugs. The 2.8L 4M40 turbo‑diesel variant does not use spark plugs, it uses glow plugs for cold starts. So spark plugs are only relevant to owners of petrol 1998 Pajeros.

For diesel models, there’s no spark because combustion is by compression ignition. The fuel/air mix ignites under high compression, and glow plugs simply preheat the chambers for easier cold starts. Different parts, different job.

For petrol 1998 Pajero owners, spark plugs do the heavy lifting every time the key’s turned. Each plug fires to ignite the air–fuel mix in the V6, keeping the engine smooth, efficient and ready for a bit of towing or a trip out bush. Healthy plugs help with clean starts on cold mornings, better fuel economy around town, and strong pull under load. They also keep emissions in check and reduce the chance of misfires that can stress coils and the catalytic converter.

Servicing intervals depend on plug type and driving. Standard copper plugs are often due around 40,000–50,000 kilometres, while long‑life platinum or iridium designs can run much longer (often up to about 100,000 kilometres). Always follow the Mitsubishi handbook and the plug maker’s guidance, frequent short trips, dusty tracks and lots of idling can shorten real‑world life.

• Hard starting, rough idle, or a stumble climbing hills
• Sluggish acceleration or higher fuel use
• Visible fouling on removed plugs (sooty or oily tips)

When replacing, do all six at once for a matched set. Access on the rear bank of the V6 can be tight, on many 6G7x Pajeros the upper intake plenum may need to come off, so budget for a fresh plenum gasket. Inspect leads and boots (or coil boots) while you’re there, and replace anything perished. Check the specified plug type and heat range for your exact engine code. Most modern plugs are pre‑gapped, only adjust if the manufacturer says it’s OK. Start threads by hand to avoid cross‑threading, use a torque wrench to the spec in the service manual, and fit to a cool engine. Avoid anti‑seize unless the plug maker expressly recommends it, as it can alter torque values.

Stay on top of spark plug servicing and the Pajero’s V6 will run cleaner, start easier and feel more eager, with fewer dramas off‑road or on the motorway.

• Popular questions about 1998 Mitsubishi Pajero spark plugs

How often should spark plugs be changed on a 1998 Pajero petrol?
For many petrol Pajeros, standard copper plugs are typically due around 40,000–50,000 km, while platinum/iridium types can go much longer, often near 100,000 km. The exact interval depends on the engine code, plug type and how the vehicle’s driven. Short trips, heat, dust and towing can bring the interval forward, so checking condition during regular servicing is smart.

Which spark plug type is best — copper, platinum or iridium?
Copper plugs are affordable and work well but need more frequent changes. Platinum and iridium cost more up front but hold their gap longer and resist wear, which helps maintain smooth running over higher kilometres. Choose the correct heat range and specification listed for the 6G72 or 6G74 in reputable plug catalogues or the Mitsubishi manual.

Does the 1998 Pajero diesel have spark plugs?
No. The 2.8L 4M40 turbo‑diesel doesn’t use spark plugs, it uses glow plugs to aid cold starts. If a diesel Pajero is hard to start cold, testing the glow plugs and their relay is the place to begin.