Parts for your 2021 Honda Civic-Sump plug washers

2021 Honda Civic sump plug washers

For the 2021 Honda Civic, a sump plug washer is absolutely fitted and required. Technical sources including the Honda Owner’s Manual for the 2021 Civic (Maintenance – Engine Oil), Honda Service Information (SIS) procedures for “Engine Oil Replacement”, and the Honda Genuine Parts Catalogue specify a 14 mm aluminium crush washer for the engine oil drain bolt. The common Honda part cited is Washer, Drain Plug (14 mm), P/N 94109-14000. These sources also note the washer should be replaced at each oil change. That applies across 2021 Civic variants sold in Australia and New Zealand, whether equipped with the 1.8-litre or 1.5-litre turbo petrol engines.

The sump plug washer’s job is to create a reliable seal between the drain bolt and the alloy sump. Being a crush (deformable) washer, it compresses once when the bolt is torqued, filling microscopic gaps and preventing oil weeps. Because it’s designed for single-use compression, reusing it can lead to seepage, loosening over time, or scuffing the sump face. That’s why Honda service literature calls for fitting a new washer at every service.

As part of regular servicing on a 2021 Honda Civic, it’s smart to keep a few genuine or high-quality equivalent washers on hand. After draining the oil, the mating surface on the sump should be wiped clean, a fresh 14 mm aluminium crush washer slipped onto the drain bolt, and the bolt then tightened to the torque value shown in the vehicle’s service data. Doing this helps maintain correct clamp load without over-tightening, which protects the sump threads and keeps the plug from backing out. If there’s any sign of dampness around the plug after an oil change, it usually points to a reused or incorrect washer.

• Use a new 14 mm aluminium crush washer (Honda P/N 94109-14000 or equivalent) at every oil change.
• Clean the sump sealing face and the drain bolt head before refitting.
• Start the plug by hand to avoid cross-threading, torque to the spec in Honda service data.
• Replace the drain bolt if its flange is burred or the hex is rounded.
• Dispose of used oil and the old washer responsibly at a local recycling facility.

Done right, a fresh washer is cheap insurance against leaks and keeps the Civic’s servicing neat and tidy.

How often should the sump plug washer be replaced on a 2021 Honda Civic?

Honda’s service information calls for replacing the sump plug washer at every engine oil change. Because it’s a crush-style, single-use seal, it deforms once and won’t reliably reseal a second time. Swapping it each service helps prevent annoying drips and keeps the drain bolt torque accurate.

What size sump plug washer does the 2021 Honda Civic use?

The 2021 Civic uses a 14 mm aluminium crush washer for the engine oil drain bolt. Honda commonly lists it as Washer, Drain Plug (14 mm), P/N 94109-14000. A quality equivalent that matches the material, inner diameter and thickness will also do the job.

Can the sump plug washer be reused if it looks fine?

Best practice is no. Even if it looks okay, a crush washer has already compressed and may not seal properly when reused. That can lead to slow weeps, a loose plug, or the temptation to overtighten. Fit a new washer each time and torque the plug to the value in the service manual.