Parts for your 2011 Mazda Cx-5-Sump plug washers

2011 Mazda CX-5 Sump Plug Washers

A sump plug washer is used on the 2011-build Mazda CX-5 (KE series). Mazda’s KE workshop manual for the CX-5 specifies fitting a new drain plug gasket during every engine oil change and lists the drain plug torque, which relies on a deformable washer to seal properly. Mazda’s electronic parts catalogue for the KE series also includes a dedicated “Gasket, Oil Drain Plug” for the CX-5, confirming the washer is a standard service item.

On the CX-5, the sump plug washer is a simple crush washer that sits under the engine oil drain plug. When the plug is tightened to spec, the washer compresses slightly to create a positive seal between the plug and the alloy sump. That prevents those annoying weeps, drips on the driveway, and the burnt-oil whiff you get when a slow leak hits hot exhaust. It also means the plug doesn’t need to be over-tightened to stop a leak, protecting the sump threads from damage.

Best practice is to replace the washer at every oil change. Mazda’s service info for the KE CX-5 calls for installing a new gasket and tightening the plug to around 30–41 N·m. On most CX-5 petrol and diesel engines, the washer is a 14 mm crush type (aluminium or copper). Genuine or quality aftermarket washers are fine—just match the size and style. If the old washer sticks to the sump, flick it off before refitting, double-stacking can cause leaks. Don’t use sealants or thread tape, the washer does the sealing.

Servicing intervals vary, but in Australia and New Zealand many owners change oil every 10,000 km or 12 months, so keeping a couple of spare washers in the glovebox isn’t a bad shout. A small torque wrench is handy to hit the spec cleanly, avoid the rattle gun. If a leak persists after a new washer and correct torque, inspect the plug and sump seat for nicks—an inexpensive new plug often sorts it.

• Signs a washer is due: dampness or weeping around the plug, a drip after parking, or a light oil mist on the undertray.
• Materials: aluminium seals a touch softer, copper is a bit more durable—either works if sized correctly.

Popular questions

What size sump plug washer does a 2011 Mazda CX-5 use?
Most 2011-build CX-5 (KE) models use a 14 mm crush washer on the drain plug. Aluminium or copper types are both common. If in doubt, check by VIN or measure the plug shoulder and existing washer before buying.

How often should the sump plug washer be replaced on a CX-5?
Replace it at every oil change. Mazda’s service guidance for the KE CX-5 specifies fitting a new gasket each time the oil is drained, then tightening the plug to about 30–41 N·m. It’s a cheap part that helps avoid leaks and stripped threads.

Can the old washer be reused?
It’s not recommended. Crush washers are designed to deform once. Reusing can lead to weeping or the need to over-tighten the plug, which risks damaging the sump. Fit a new washer and torque it correctly for a tidy, reliable seal.