Parts for your 2007 Subaru Outback-Sump plug washers

2007 Subaru Outback sump plug washers

Yes, a sump plug washer is used on the 2007 Subaru Outback. Subaru’s 2005–2009 Legacy/Outback Service Manual (Lubrication section – Engine Oil Replacement) specifies fitting a new drain plug gasket and tightening the plug to 44 N·m during an oil change. The 2007 Owner’s Manual echoes this by instructing to install a new gasket when refitting the drain plug. Subaru’s parts catalogue also lists the Engine Oil Drain Plug Gasket, P/N 803916010 (aluminium, 16 mm), for EJ25 and EZ30 engines fitted to 2007 Outback models. Those technical sources make it clear the washer is required.

On this Outback, the sump plug washer—sometimes called a crush washer or drain plug gasket—does the quiet but critical job of sealing the oil pan. It’s designed to deform slightly as the plug is torqued, filling any tiny imperfections between the drain plug and the sump. That one-time “crush” prevents annoying weeps, protects the pan threads from over-tightening, and helps the plug reach its proper clamping load without drama.

Best practice is to replace the washer at every service where the engine oil is changed. They’re inexpensive, and reusing an old one can lead to seepage that coats the underside with oil mist, or worse, invites over-tightening to chase a seal. For this model, the genuine Subaru aluminium 16 mm washer (803916010) is the safe bet, and quality aftermarket 16 mm crush washers are fine as long as they match spec.

When servicing a 2007 Outback:

• Warm the engine, then drain the oil and remove the old washer from the plug.
• Clean the mating surfaces, don’t use thread tape or sealant—let the crush washer do the sealing.
• Fit a fresh washer, start the plug by hand, then torque to 44 N·m with a torque wrench.
• Refill oil, run the engine, and check for any weeps once it’s up to temp.

Some washers are symmetrical, others have a slight chamfer—fit them as marked by the manufacturer. Copper and aluminium both work, aluminium is what Subaru supplies for this generation. Keeping a few spares in the service kit makes life easy at oil-change time, and sticking to a new washer every change keeps the Outback tidy and leak-free.

Popular questions about 2007 Subaru Outback sump plug washers

What size sump plug washer does a 2007 Subaru Outback use?
It uses a single-use 16 mm crush washer on the engine oil drain plug. The Subaru genuine part is an aluminium gasket, P/N 803916010, and it suits both the EJ25 and EZ30 engines used in this model year.

How often should the sump plug washer be replaced?
Swap it at every oil change. The washer is designed to crush once to seal perfectly, reusing it can lead to seepage or the temptation to over-tighten the plug.

What torque should the sump plug be tightened to?
Subaru specifies 44 N·m for the 2007 Outback’s engine oil drain plug in the 2005–2009 Legacy/Outback Service Manual. Always start the plug by hand on a fresh washer, then verify no leaks after a warm-up.