Parts for your 2023 Mitsubishi Eclipse cross-Sump plug washers

2023 Mitsubishi Eclipse Cross sump plug washers: are they used and why they matter

Yes — the 2023 Mitsubishi Eclipse Cross uses a sump plug washer (also called a drain plug gasket). Technical sources that confirm this include:

• Mitsubishi Motors Eclipse Cross (GK/GL) Service Manual, Engine Lubrication section: specifies fitting the drain plug with a new gasket during engine oil replacement.
• Mitsubishi ASA Electronic Parts Catalogue for Eclipse Cross GK: lists the engine oil drain plug gasket as an aluminium crush washer, part number 1100A141 (commonly supplied in multi-pack MZ690065).
• Professional data platforms (e.g., Autodata service schedules for the 4B40 1.5T engine) note “renew drain plug sealing washer at oil change”.

For owners and workshops, that means the Eclipse Cross sump-plug-washers are very much a service item. The little aluminium ring does a big job: it crushes slightly as the sump plug is tightened, creating a reliable seal between the plug and the alloy sump. That one-time crush is what prevents those annoying weeps on the driveway and helps the plug reach the correct clamping force without over-tightening.

During routine servicing, it’s best practice to replace the sump-plug-washers every time the oil is changed. Mitsubishi’s own service information calls for installing the plug with a new gasket, and the parts catalogue backs this with the dedicated washer listing (1100A141). Reusing an old washer can lead to seepage, and chasing a slow leak later is a pain no one needs. A fresh washer costs next to nothing and protects the sump threads by allowing the plug to be torqued correctly first go.

What does a good replacement look like? For the 2023 Eclipse Cross, it’s a 14 mm ID aluminium crush washer. Genuine parts come singly or in packs (MZ690065), and there are quality aftermarket equivalents that match the dimensions. When the oil’s drained and the filter’s done, fit a new washer to a clean plug, thread it in by hand to avoid cross-threading, then tighten to the factory spec in the service manual. After the first drive, a quick glance for any sign of misting around the plug is a smart final check.

If the vehicle’s had a prior repair or non-standard plug fitted, confirm washer size by VIN or measuring the plug shank. Otherwise, sticking with the specified Eclipse Cross sump-plug-washers keeps the lubrication system tidy, leak-free, and ready for the next 15,000 km service interval.

• What size sump plug washer does a 2023 Eclipse Cross use?

The Eclipse Cross typically uses a 14 mm ID aluminium crush washer. In Mitsubishi parts, that’s the 1100A141 washer, often supplied in the MZ690065 multi-pack. If the sump plug has been changed in the past, double-check by VIN or measuring the plug shank to be sure.

• Should the sump plug washer be replaced at every oil change?

Yes. It’s designed to deform once to seal properly. Reusing an old washer can cause weeping leaks and make correct torque harder to achieve. Swapping it at each oil change is cheap insurance for a clean, dry sump.

• Can a copper or fibre washer be used instead of aluminium?

Aluminium is the OE style for the Eclipse Cross and gives the right crush against the alloy sump. Quality copper can work in a pinch if the dimensions match, but staying with the specified aluminium type is the safest bet for repeatable sealing and torque feel.