Parts for your 2004 Toyota Highlander-Sump plug washers

2004 Toyota Highlander (Kluger) sump plug washers

Toyota fitted the 2004 Highlander (known as Kluger in Australia and New Zealand) with a replaceable sump plug washer on the engine’s oil drain plug. This is a crush-type sealing gasket that’s intended to be renewed at each oil change. Technical sources that specify this include Toyota’s Repair Manual for the 2AZ‑FE (2.4L) and 3MZ‑FE (3.3L) engines, which instructs installing a new drain plug gasket and tightening the plug to approximately 39 N·m (29 ft·lbf). Toyota’s Electronic Parts Catalogue for ACU20/25 and MCU23/28 models lists the engine oil drain plug gasket as 90430‑12031 (aluminium crush type). Those factory references confirm that a sump plug washer is relevant and used on this model.

This little ring does a big job. The sump plug washer sits between the drain plug and the alloy or steel sump, crushing slightly as the plug is torqued down to create a fluid-tight seal. On the 2004 Highlander/Kluger, Toyota specifies a single-use crush washer so the sealing face conforms perfectly each time the oil is changed. It helps prevent weeping after a hot run and stops that annoying drip that can stain the driveway or set off an oil smell.

Because it’s designed to deform, the washer should be replaced whenever the plug is removed. Reusing an old one risks seepage or needing extra torque on the plug, which is not ideal for the sump threads. With the Highlander/Kluger, the smart play is a new genuine or quality aftermarket M12 crush washer (Toyota P/N 90430‑12031) every service. Fit the clean washer, thread the plug by hand, then torque to about 39 N·m. No rattle-gun heroics needed.

Tell-tales of a tired washer include a damp halo around the plug, a drop of oil forming overnight, or residue collecting dust on the sump. If any of that shows up, swap the washer and recheck the torque once the engine’s cooled. Owners who do their own servicing often keep a few washers on hand—they’re cheap insurance. Aluminium is OE, while copper options seal well too, avoid hard, reusable plastics on this engine. And if the vehicle also has its transmission or transfer drain opened during service, remember those plugs use their own dedicated crush washers as well.

Technical sources referenced: Toyota Repair Manual (2004 Highlander/Kluger, 2AZ‑FE and 3MZ‑FE – Lubrication section: “Install a new drain plug gasket, tighten to 39 N·m [29 ft·lbf]”), Toyota Electronic Parts Catalogue (ACU20/25, MCU23/28, 2004) listing Gasket, Drain Plug 90430‑12031 for engine oil pan.

• Recommended torque for engine sump plug: approx. 39 N·m (29 ft·lbf)
• Recommended gasket: Toyota 90430‑12031 (M12 aluminium crush washer)
• Replace the washer at every engine oil change

Popular questions about 2004 Toyota Highlander sump plug washers

What size and part number is the sump plug washer on a 2004 Highlander/Kluger?
It uses an M12 crush washer. Toyota’s genuine part is 90430‑12031 (aluminium). This suits both the 2AZ‑FE 2.4L and the 3MZ‑FE 3.3L engines fitted to 2004 models.

How often should the sump plug washer be replaced?
Replace it every time the engine oil is changed. It’s a single-use crush washer, so once deformed it won’t seal as reliably the second time. They’re inexpensive and help prevent annoying leaks.

What torque should the sump plug be tightened to when using a new washer?
Toyota specifies about 39 N·m (29 ft·lbf) for the engine sump plug. Always start the plug by hand, fit a new washer, and torque correctly to avoid damaging the sump threads or distorting the seal.