Parts for your 2018 Toyota Vitz|yaris-Sump plug washers

2018 Toyota Vitz/Yaris sump plug washers

Based on Toyota technical sources, the 2018 Toyota Vitz/Yaris uses a sump plug washer (crush washer) on the engine oil drain plug. The Toyota Repair Manual for the Vitz/Yaris (2017–2019) instructs “replace the gasket” when refitting the drain plug and specifies a torque around 27 N·m. Toyota’s parts catalogues for the KSP/NSP/NHP130 series list a genuine drain plug gasket, typically part number 90430-12031 (M12 aluminium crush washer). That confirms a sump plug washer is relevant and fitted on this model.

For the 2018 Toyota Vitz/Yaris, the sump plug washer’s whole job is to seal the oil drain plug against the sump so engine oil doesn’t seep or drip. It’s a small, soft-metal ring—usually aluminium on these Toyotas—that deforms slightly when the plug is torqued up. That controlled “crush” fills microscopic gaps between the plug flange and the sump face, creating a reliable, pressure-tight seal even as the alloy pan and steel plug expand and contract with heat cycles.

Because it’s designed to crush once, Toyota service information calls for replacing the washer at every oil change. Reusing a flattened or scored washer can lead to weeping oil, stubborn drips on the drive, or the temptation to over-tighten the plug to stop a leak—risking stripped threads in the sump. The smart play is to keep a couple of spares on hand and swap a new washer in whenever the oil is drained.

Good practice on this Vitz/Yaris includes cleaning the sump’s mating face, fitting the correct M12 washer (genuine 90430-12031 or a quality equivalent), and tightening the plug to about 27 N·m with a torque wrench. After the service, run the engine, switch off, and check for any signs of seepage around the plug once the oil has settled. If there’s a magnetic drain plug fitted, a quick look for excessive metal fuzz is also worthwhile—it’s a handy early warning for wear.

Owners in Australia and New Zealand typically service these cars at 10,000–15,000 km or 12 months, depending on driving conditions. At that interval, a fresh washer is inexpensive insurance against nuisance leaks. Aluminium is the usual pick for Toyotas, though copper washers also work if they match the size and seat style. Avoid oversized “universal” washers that can distort or mis-seat on the Yaris sump face.

• Always use the correct M12 crush washer for the Yaris/Vitz sump plug.
• Replace at every oil change, don’t over-tighten—aim for ~27 N·m.
• Clean mating surfaces and check for leaks after the service.

Popular questions about 2018 Toyota Vitz/Yaris sump plug washers

What size and part number is the sump plug washer?
The 2018 Vitz/Yaris typically uses an M12 aluminium crush washer. A common genuine Toyota number is 90430-12031. Many reputable aftermarket equivalents exist, but stick to an M12 washer sized to suit the Toyota drain plug flange so it seats and crushes correctly.

How often should the washer be replaced?
Every oil change. For most owners in AU/NZ that’s roughly every 10,000–15,000 km or 12 months. It’s a low-cost part that helps prevent leaks and avoids the temptation to over-tighten the drain plug.

What’s the correct torque for the drain plug with a new washer?
About 27 N·m is typical for the Yaris/Vitz of this generation. Using a torque wrench helps avoid stripped threads in the alloy sump and ensures the crush washer seals as intended.