Parts for your 2018 Mitsubishi Asx-Manifold gasket

2018 Mitsubishi ASX manifold-gasket — what it is and when to sort it

Technical sources confirm the 2018 Mitsubishi ASX uses manifold gaskets. The Mitsubishi Motors service manual for ASX/RVR/Outlander Sport (engine mechanical sections) specifies both intake manifold and exhaust manifold gaskets for the petrol 2.0L 4B11 and the diesel 2.2L 4N14, with a directive to install new gaskets after removal. OEM electronic parts catalogues (Mitsubishi ASA) and mainstream repair databases also list these gaskets for the 2018 model year. So yes — a manifold-gasket is relevant and fitted to the 2018 ASX.

On this ASX, the manifold-gasket quietly keeps things airtight and leak-free where the manifolds bolt to the cylinder head. The intake manifold gasket stops unmetered air sneaking in, which protects smooth idle, stable fuel trims and decent fuel economy. The exhaust manifold gasket seals hot gases on their way to the cat and turbo (diesel), preventing that tell-tale ticking on cold start, keeping fumes out of the cabin, and ensuring the oxygen sensors and emissions gear read true.

It isn’t a scheduled replacement item, but it’s a must-replace any time a manifold is removed. Over time, heat cycling, vibration and slight warping can crush or harden the gasket. Typical symptoms include a hiss or whistle (intake), a ticking or chuffing noise from the exhaust side, a sooty stain near the flange, rough idle, slower take-off, lean-mixture fault codes (like P0171 on petrol), and a whiff of exhaust under the bonnet.

Good service practice on the 2018 ASX looks like this:

• Any manifold off? Fit a new OEM-quality gasket, don’t reuse the old one.
• Clean mating faces gently (no gouging), check straightness with a straightedge.
• Follow the factory torque values and bolt-tightening sequence, heat shields back on.
• Avoid smearing RTV unless the manual specifically calls for it at joints.
• For the diesel, inspect EGR connections and turbo fasteners while you’re there.

Owners in Aussie and Kiwi conditions will often notice issues after long highway kilometres, frequent short trips, or towing. A competent workshop usually knocks over an intake gasket job in roughly 1–2 hours, exhaust side can take longer thanks to heat-shielding and stubborn fasteners. Fresh gaskets help the ASX breathe properly, keep the cabin air sweet, and protect fuel economy and engine health.

Popular questions about the 2018 Mitsubishi ASX manifold-gasket

Does the 2018 ASX actually have manifold gaskets?
Yes. Both the intake and exhaust manifolds use gaskets on the 2.0L petrol 4B11 and the 2.2L diesel 4N14. Factory literature specifies new gaskets on reassembly, so they’re absolutely part of the engine’s sealing system.

What are the signs a manifold-gasket is failing on this model?
Look for a hissing or whistling noise (intake), or a ticking/chuffing on cold start (exhaust). Other clues include rough idle, higher fuel use, lean fault codes, exhaust smell under the bonnet, or soot marks around the manifold-to-head joint.

Can the gasket be reused to save a few dollars?
Not recommended. The Mitsubishi procedure calls for new gaskets once disturbed. Reusing a crushed or heat-cycled gasket risks leaks, warped mating faces, and repeat labour. Fit a quality replacement and torque it properly the first time.