Parts for your 1998 Mitsubishi Pajero-Exhaust gasket

1998 Mitsubishi Pajero exhaust gasket — what it does and when to replace it

Technical sources including the Mitsubishi factory workshop manual for 1997–2000 Pajero/Montero (Exhaust System and Engine sections) and the Mitsubishi ASA electronic parts catalogue confirm that the 1998 Mitsubishi Pajero does use several exhaust gaskets. These include the cylinder head–to–exhaust manifold gasket, the manifold/front pipe “donut” (spherical ring) gasket with spring bolts, and downstream flange gaskets, turbo‑diesel variants also have turbo outlet/inlet gaskets.

On this Pajero, exhaust gaskets seal super‑hot gases as they leave the engine, keeping the system quiet, preventing fumes entering the cabin, and ensuring accurate oxygen sensor readings. On turbo diesels, a sound seal ahead of the turbine helps spool and keeps EGT and boost behaviour on song. Gaskets cop big heat cycles, vibration, and slight movement at joints, so they’re made from multi‑layer steel or graphite composites and, in the case of the front pipe, a crush‑style donut that self‑centres under spring tension.

As part of routine servicing, these gaskets deserve a once‑over. The factory manual notes gaskets are single‑use once disturbed, so any time the manifold, front pipe, or turbo plumbing is removed, fresh gaskets should be fitted. Regular checks help catch small leaks before they cook studs or warp flanges.

• Typical leak clues: a ticking or puffing noise on cold start, black soot marks at joints, exhaust odour near the bonnet or firewall, and a slight loss of grunt or poor fuel economy.
• Visual checks: look at the manifold/head junction, the spring‑bolt donut joint, turbo flanges (diesel), and rear flange joints for soot or streaks.

When replacing, clean mating faces back to bare metal without gouging, and fit quality OEM‑spec gaskets. Install dry unless the manual specifies a sealant (most Pajero exhaust gaskets are dry‑fit). Follow the torque figures and the centre‑out sequence for the manifold, torque values differ by engine (e.g., 6G74 V6 vs 4M40 diesel), so the workshop manual should be used. Replace rusty studs, nuts, and the spring‑bolt kit with the donut gasket, as clamp load is what makes that joint seal. After the first heat cycle, recheck for any weeping or ticking. A quick smoke test or a gloved‑hand back‑pressure check at the tailpipe while listening at joints can help confirm a tight system.

Popular questions about 1998 Mitsubishi Pajero exhaust gaskets

Where are the exhaust gaskets located on a 1998 Pajero?
They’re found at the cylinder head–to–exhaust manifold, at the manifold/front pipe donut joint with spring bolts, and at various flange joints further back. Turbo‑diesel models add gaskets at the turbo inlet and outlet. Each one manages movement and heat in a slightly different way.

What are the signs of a blown exhaust gasket on this model?
Common signs include a ticking noise on cold start that softens as it warms up, black soot around a joint, exhaust smell near the engine bay, and in some cases an oxygen sensor fault code or poorer fuel economy. On diesels, a pre‑turbo leak can feel like lazy boost response.

Should sealant be used on Pajero exhaust gaskets?
Generally, no. Pajero exhaust manifold and donut gaskets are designed to be installed dry. High‑temp RTV or paste can contaminate O2 sensors and isn’t specified for these joints. If any sealant is ever called for, it will be noted in the factory workshop manual for that exact engine and joint.