Parts for your 2018 Mitsubishi Asx-Sump plug washers

2018 Mitsubishi ASX sump plug washers

Yes — the 2018 Mitsubishi ASX uses a sump plug washer. Mitsubishi’s own technical literature backs this up: the Mitsubishi Motors Workshop Manual for the ASX/Outlander Sport/RVR (4B11 petrol engine, Engine Lubrication section) specifies a replaceable crush washer on the oil drain plug and instructs replacing it whenever the plug is refitted. Typical tightening torque is cited at around 39 N·m. The Mitsubishi ASA electronic parts catalogue also lists an oil pan drain plug gasket (commonly MD050317, 14 mm) for 2018 ASX models (GA-series). That’s exactly the little ring that keeps the engine oil where it should be — inside the sump.

On the ASX, the sump plug washer (also called a drain plug gasket) is a small, soft metal ring — usually aluminium or copper — that sits between the sump plug and the sump. When the plug is tightened, the washer gently crushes to form a tight seal. Its job is simple but crucial: stop weeps and leaks as the oil heats up, cools down, and the alloy parts expand and contract. Because it’s designed to deform once, it’s considered a consumable item.

Best practice on a 2018 ASX is to replace the sump plug washer at every oil change — typically every 15,000 km or 12 months in AU/NZ conditions, unless your logbook says otherwise. Reusing a crushed washer can lead to annoying drips on the driveway, underbody mess, or, in the worst case, a sudden loss of oil pressure if a leak worsens. When refitting the plug, clean the mating faces, fit a new 14 mm crush washer, and torque the drain plug correctly (around 39 N·m for the 4B11 engine — check the workshop manual for your exact spec). Don’t swing off it with a breaker bar, over-tightening can distort the washer or damage threads.

• Keep a few genuine or quality aftermarket 14 mm washers in the glovebox or toolbox.
• Make sure the old washer isn’t stuck to the sump before refitting.
• If you spot seepage after a service, recheck torque and washer condition.
• If the plug’s been overtightened in the past, inspect threads before the next service.

Popular questions about 2018 Mitsubishi ASX sump plug washers

What size sump plug washer does a 2018 Mitsubishi ASX use?
Most 2018 ASX petrol models use a 14 mm crush washer on the oil drain plug, commonly referenced under Mitsubishi part number MD050317. Variations can exist by market or engine, so it’s smart to confirm by VIN or with the vehicle’s parts catalogue before ordering a handful.

How often should the sump plug washer be replaced?
Every oil change. The washer is a single-use crush type, once it’s flattened, it won’t seal as reliably again. Swapping it at each service is cheap insurance against leaks and avoids having to re-do the job later.

What happens if the washer is reused or missing?
Reusing a washer can cause weeping around the plug, and a missing washer makes sealing much harder — you might end up over-tightening the plug to compensate, risking damaged threads. Either way, it’s not worth the drama, fit a fresh washer and torque it properly.