Parts for your 2015 Mitsubishi Asx-Manifold gasket

2015 Mitsubishi ASX manifold gasket — what it does and when to replace it

A manifold gasket is fitted to the 2015 Mitsubishi ASX. Both the petrol (4B11 2.0L and 4A92 1.6L) and diesel (4N14 2.2L) engines use intake and exhaust manifold gaskets between the manifold flanges and the cylinder head. This is documented in Mitsubishi Motors workshop manuals (Engine – Intake and Exhaust sections) and the Mitsubishi ASA Electronic Parts Catalogue for MY2015 ASX/RVR/Outlander Sport, which list distinct intake and exhaust manifold gasket part entries. Major gasket manufacturers (Elring, Victor Reinz, Fel‑Pro) also catalogue direct-fit manifold gaskets for the 2015 model, further confirming fitment.

The manifold gasket’s job is simple but critical: it seals the join between the manifold and the head so air, fuel mix, exhaust gases and—on some setups—coolant passages stay exactly where they should. On the intake side it prevents vacuum leaks that can cause lean running, rough idle and fuel trims going haywire. On the exhaust side it keeps hot gases inside the manifold, protecting the engine bay, maintaining turbo/catalyst efficiency and ensuring the oxygen sensors get clean, consistent readings.

Manifold gaskets aren’t a scheduled service item on the ASX, but they’re cheap insurance any time the manifold is removed. Owners should keep an ear and nose out for tell-tales:

• Intake leak: hissing/whistling at idle, hunting idle, hesitation, possible lean codes (e.g., P0171).
• Exhaust leak: ticking on cold start that quietens as it warms, sooty marks near the flange, exhaust smells in the cabin, sluggish low‑down torque.

If chasing an intake leak, a smoke test or careful use of carb cleaner around the flange (with engine idling) can help pinpoint the spot—only if safe and well‑ventilated. For exhaust, look for black soot tracks, loose or heat-cycled fasteners and warped mating faces.

When replacing, go with OE or quality aftermarket gaskets: multi‑layer steel for exhaust, and moulded/composite or rubber‑coated metal for intake. Clean the mating faces, check studs and nuts, and follow the factory torque values and tightening sequence—usually working from the centre out, in stages. Avoid slathering on sealant unless the Mitsubishi manual specifically calls for a dab at corners or joints, excess goo can break loose and cause trouble. After first heat cycles, recheck fastener torque only if specified by the service manual. If the EGR pipe or throttle body comes off during the job, renew those gaskets or O‑rings too.

Look after these seals and the ASX will idle smoothly, breathe properly and keep heat where it belongs.

Popular questions about the 2015 Mitsubishi ASX manifold gasket

How can someone tell if their ASX has a leaking manifold gasket?

Common signs are a hissing or whistling noise (intake) or a ticking on cold starts (exhaust). You might also notice rough idle, higher fuel use, a lean fault code, or exhaust smell in the cabin. Soot marks around the exhaust flange are a giveaway.

A smoke test or careful spray test around the intake flange can help confirm an intake leak. For exhaust, visual inspection and listening with a mechanic’s stethoscope work well.

Should the manifold gaskets be replaced every time the manifold is removed?

Yes—best practice is to replace them whenever the manifold comes off. Once compressed and heat‑cycled, old gaskets don’t always reseal perfectly. Fresh gaskets are inexpensive compared with the time to redo the job.

Also inspect studs and nuts, and clean the mating faces before refitting.

Is it safe to drive with a small exhaust manifold gasket leak?

It’s not ideal. Small leaks can draw in oxygen and skew O2 sensor readings, upset fuel trims, overheat nearby components, and in some cases allow fumes into the cabin. Short trips to a workshop are generally fine, but it’s wise to repair promptly.