Parts for your 2012 Mitsubishi Lancer-Sump plug washers

2012 Mitsubishi Lancer sump plug washers — what they do and when to replace them

Technical sources confirm the 2012 Mitsubishi Lancer uses a replaceable sump plug washer (crush gasket) on the engine oil drain plug. The Mitsubishi Motors Lancer CJ/CF Workshop Manual for the 4B1-series engines instructs fitting the drain plug “with a new gasket” and tightening to around 39 N·m. The Mitsubishi ASA parts catalogue also lists an oil drain plug gasket for these models, commonly the aluminium 14 mm washer (e.g., MD050317). So, yes — a sump-plug-washer is fitted and is part of normal servicing on a 2012 Mitsubishi Lancer.

On this Lancer, the sump-plug-washer is a small, soft-metal ring that crushes once to seal the drain plug to the alloy sump. Its job is simple but vital: stop slow weeps and drips after an oil change, protect the sump face from gouging, and help achieve the correct clamp load at the specified torque. Because it’s designed to deform, it’s considered single-use. Reusing a flattened washer often leads to that tell-tale oil mist around the plug, the driveway spots, and the warm-oil whiff after a run.

For a 2012 Mitsubishi Lancer, the common size is a 14 mm inside-diameter crush washer. Aluminium is most typical from the factory, though compatible copper options exist. During an oil change, the old washer should be removed and binned, the sump face and plug cleaned, and a new washer installed before tightening the plug to about 39 N·m. Leaning on the spanner harder won’t seal a tired washer, it just risks stripping sump threads. If the plug head is rounded or the sealing face is nicked, replace the plug as well.

Good practice on this model is to replace the sump-plug-washer at every oil service interval. It’s a low-cost item that prevents far pricier hassles. After the first heat cycle, have a quick look underneath for any fresh oil tracking, if there’s even a slight weep, fit a fresh washer and re-torque to spec. For those who like spares on hand, keep a small sachet of 14 mm crush washers in the glovebox or tool tray — very handy when doing DIY servicing on a Lancer. Technical references: Mitsubishi Motors Lancer CJ/CF Service Manual (Engine Lubrication – 4B10/4B11/4B12), and Mitsubishi ASA parts listings for the oil drain plug gasket (MD050317).

• Washer type: 14 mm crush washer (aluminium commonly used)
• Torque guide: approximately 39 N·m (always follow the vehicle’s workshop manual)
• Replace: every oil change or whenever the plug is removed

Popular questions about 2012 Mitsubishi Lancer sump-plug-washers

What size sump-plug-washer does a 2012 Lancer use?
The 2012 Lancer typically takes a 14 mm inside-diameter crush washer, often aluminium (OEM example MD050317). Engine variants in the 4B1 family share this spec, but it’s smart to match the washer to your actual drain plug before fitting.

How often should the sump-plug-washer be replaced?
Best practice is every oil change. A crush washer is single-use by design, once compressed, it can’t reliably reseal. Replacing it each service helps prevent drips and avoids overtightening the plug to chase a seal.

What’s the correct torque for the drain plug on a 2012 Lancer?
The workshop manual specifies about 39 N·m for the 4B1-series engines. Use a torque wrench and a new washer. If you’re unsure of your exact variant, check the service manual for your engine code and market spec.