Parts for your 2004 Subaru Forester-Sump plug washers

2004 Subaru Forester sump plug washers

Yes, the 2004 Subaru Forester uses a sump plug washer (also called an oil drain plug gasket), and it’s considered a service-replaceable item. This is documented in Subaru’s Factory Service Manual for the Forester (SG, Lubrication section), which specifies replacement of the drain plug gasket during oil changes, and in Subaru’s genuine parts catalogue listing the aluminium crush washer, Oil Drain Plug Gasket P/N 11126AA000, used across EJ-series engines fitted to 2004 Forester models. General repair references such as the Haynes workshop manual for Subaru Forester/Legacy/Outback of the era also note to always renew the drain plug sealing washer when refitting.

On the 2004 Forester, the sump plug washer is a soft aluminium crush washer that deforms once to create a reliable seal between the steel drain plug and the oil pan. Its job is dead simple but absolutely vital: keep engine oil where it belongs, stop weeps, and allow the correct torque without over-stressing the sump threads. Reusing a flattened washer can lead to annoying drips on the driveway or, worse, overtightening to chase a seal and risking stripped threads in the pan.

Best practice is to replace the washer at every oil change (typically every 10,000–12,500 km or 6 months, depending on your service schedule and conditions). Subaru’s single-use design means once it’s crushed, it’s done. Use the correct aluminium type and size specified for EJ motors—Subaru P/N 11126AA000 or a quality equivalent—and avoid stacking washers or mixing materials that don’t crush properly.

When servicing the Forester’s sump plug, clean the mating face on the pan, fit a new washer to the plug, and torque the plug correctly—44 N·m is the typical spec for EJ engines of this generation. Hand-start the plug to avoid cross-threading, torque it evenly, then run the engine and check for any seepage. If there’s still a weep, don’t swing off a longer spanner, remove the plug, confirm the washer is correct and clean, and refit to spec.

• Replace washer at every oil change.
• Use an OEM-equivalent aluminium crush washer (Subaru 11126AA000).
• Clean sealing faces, never double up washers.
• Tighten to about 44 N·m, recheck for leaks after a short drive.

Popular questions about 2004 Subaru Forester sump plug washers

What size sump plug washer does a 2004 Forester use?
It uses the Subaru aluminium crush washer commonly supplied as P/N 11126AA000 for EJ engines. This matches the factory drain plug and pan seat used on 2004 Forester models, ensuring a proper crush and seal when torqued to spec.

Can the sump plug washer be reused?
Not recommended. It’s a single-use crush washer. Once flattened, it won’t deform correctly again, which can cause weeping or tempt over-tightening. Fit a fresh aluminium washer at each oil change for a no-drama seal.

What torque should the sump plug be tightened to?
For EJ-powered Foresters of this year, the typical torque is about 44 N·m. Using a torque wrench helps protect the sump threads and ensures the new washer crushes just right for a clean seal.