Parts for your 2014 Subaru Impreza-Sump plug washers

2014 Subaru Impreza sump plug washers: what they do and when to replace them

Yes, the 2014 Subaru Impreza uses a sump plug washer. Subaru’s own technical sources back this up: the Subaru Factory Service Manual for the 2012–2016 Impreza (lubrication section) specifies replacing the drain/sump plug gasket whenever the plug is removed, and the Subaru parts catalogue lists an aluminium crush gasket (commonly supplied as Genuine Subaru Gasket, Drain Plug, part number 803916010) for this model. That means the sump plug washer is very much a relevant service item on a 2014 Impreza.

On this car, the sump plug washer is a small, single-use aluminium ring that sits between the sump plug head and the oil pan. When the plug is tightened, the washer “crushes” slightly to create a reliable seal. That crush action compensates for tiny imperfections in the mating surfaces and helps prevent oil weeping or drips after a service. It also spreads the load so the alloy sump face isn’t damaged by over-tightening.

Because it’s designed to deform, the washer should be replaced every time the engine oil is changed. Reusing a crushed washer is a false economy: it may not seal properly the second time, which can lead to slow leaks, a mess on the driveway, and the risk of oil loss on a long trip. Subaru’s service guidance is clear—fit a new washer and torque the plug to spec in the FSM for the engine variant in the vehicle.

For a tidy, trouble-free service on a 2014 Impreza, a new genuine-style aluminium washer is the go-to. When changing oil:

• Clean the sump plug threads and the pan face.
• Fit a fresh aluminium crush washer, correct side against the sump (if the washer is sided).
• Tighten the plug to the factory torque spec—don’t just lean on it with a long bar.
• Wipe down and check for any seepage after the engine’s run and cooled.

Signs the old washer’s had it include a light oil halo around the plug, a damp plug head, or a drip forming after a drive. If any of that shows up, replace the washer and re-torque the plug. Sticking with the correct Subaru-listed washer keeps the sealing geometry right and avoids galvanic issues that can happen with the wrong materials.

Popular questions about 2014 Subaru Impreza sump plug washers

What size washer does the 2014 Subaru Impreza use?
Subaru typically supplies an aluminium crush washer matched to the Impreza’s sump plug via the parts catalogue (commonly referenced as Genuine Subaru 803916010). Rather than chasing millimetre dimensions, the simplest way to get it right is to order by VIN or ask for the drain plug gasket for a 2014 Impreza. That ensures the inner diameter and thickness match the OEM plug and sump face properly.

How often should the sump plug washer be replaced?
Every oil change. The washer is a crush-type seal that deforms once to create a proper seal. Reusing it can cause weeping or drips. Replace it whenever the plug comes out, and torque the plug to the factory spec shown in the Subaru service manual for the engine in your car.

Can a copper or fibre washer be used instead of aluminium?
It’s best to stick with the aluminium crush washer Subaru specifies for the 2014 Impreza. Other materials may not crush the same way or may alter the clamp load and sealing surface contact. If an alternative is used in a pinch, check for leaks after heat cycling and replace with the correct Subaru-listed washer at the next service.