Parts for your 2015 Mitsubishi Asx-Head gasket

2015 Mitsubishi ASX Head Gasket: What it does and how to look after it

Based on Mitsubishi technical literature, a head gasket is absolutely used on the 2015 Mitsubishi ASX. The Mitsubishi Motors Workshop Manual for the ASX/RVR (GA-series) covering the 4B11 2.0L petrol and 4N13/4N14 diesel engines, along with the Mitsubishi ASA electronic parts catalogue, clearly lists a multi‑layer steel (MLS) cylinder head gasket and associated torque‑to‑yield head bolts for these engines. So yes, the 2015 ASX is fitted with a head gasket.

In the ASX, the head gasket sits between the aluminium cylinder head and the engine block, sealing three critical circuits: combustion pressure, engine oil, and coolant. Its job is to keep compression in the cylinders while stopping oil and coolant from mixing or escaping. The MLS design used by Mitsubishi copes with heat cycling and clamping loads, helping the engine run smoothly, quietly, and efficiently under the bonnet.

While the head gasket isn’t a routine “service item”, looking after the cooling system and lubrication is the best way to keep it happy. Overheating is a head gasket’s worst enemy. Sticking to the correct long‑life coolant type and change interval specified by Mitsubishi, keeping the radiator and thermostat in good order, and replacing a tired radiator cap can all reduce stress on the gasket. The same goes for timely oil changes with the right spec oil to maintain proper seal integrity and heat management.

If trouble ever brews, classic signs include unexplained coolant loss, white exhaust vapour when warm, pressurised hoses from cold, rough cold starts, or milky residue on the oil cap. Pros will confirm with a cooling‑system pressure test, a chemical block test for combustion gases in coolant, and compression or leak‑down tests.

Replacement is a skilled job. The cylinder head must be checked for flatness and surface finish, the timing (chain on the 4B11, belt/chain arrangements vary on diesels) must be set correctly, and new head bolts and gaskets should be used. No re‑torque is typically required on MLS setups when installed to the factory procedure. It’s smart to renew the thermostat, coolant, and engine oil/filter at the same time, and on diesels, to inspect EGR coolers for leaks that can mimic or contribute to overheating. Expect a full‑day to two‑day workshop booking depending on engine and findings.

• Keep coolant fresh and correct type, fix leaks promptly.
• Watch temps on long climbs or towing, don’t ignore an overheating light.
• Address misfires, detonation, or tune issues that can spike cylinder pressures.

How long does a head gasket last on a 2015 Mitsubishi ASX?

With proper cooling‑system and oil maintenance, many last the life of the engine. It’s common to see reliable service well beyond 150,000–300,000 km if the engine is kept cool and clean.

What are the early warning signs of a failing head gasket on an ASX?

Persistent coolant loss, sweet‑smelling white vapour from the exhaust once warm, bubbles in the expansion tank, overheating under load, and creamy residue on the oil cap are all red flags. A professional pressure or block test will pinpoint the issue.

Is a head gasket replacement worth it on this model?

Often yes, especially if the ASX is otherwise in good nick. Labour can range widely (roughly 8–14 hours on a transverse four), and final cost depends on machining needs and what’s replaced while there. A thorough quote and inspection will help decide.