Parts for your 2015 Subaru Impreza-Oil cap

2015 Subaru Impreza Oil Cap — Purpose, Care, and When to Replace

Technical sources confirm the 2015 Subaru Impreza is absolutely fitted with an engine oil filler cap. The 2015 Subaru Impreza Owner’s Manual directs owners to remove and refit the oil filler cap when checking and topping up engine oil, and Subaru’s official parts catalogue lists a “Cap – Oil Filler” for the FB20 engine used in this model. So yes—an oil cap is relevant and required on this vehicle.

On a 2015 Impreza, the oil cap lives under the bonnet on top of the engine, typically marked with the oil can symbol. Its job is simple but vital: it seals the oil filler opening to keep dust, moisture, and grit out, and it helps maintain proper crankcase pressure so the engine breathes as it should through the PCV system. A healthy cap and gasket reduce the chance of oil misting onto the rocker cover, and help prevent odd idle issues that can pop up if there’s an air leak.

As part of servicing, the oil cap deserves a quick once-over every time the oil’s changed. The sealing ring can harden or flatten with heat cycles, and the cap threads can collect grime. A minute spent cleaning and inspecting can save a messy engine bay—and a whiff of burnt oil—down the track.

• Clean: Wipe the cap and filler neck threads with a lint-free cloth.
• Inspect: Check the rubber seal/O-ring for cracks, cuts, or a “shiny” flattened look.
• Refit: Screw the cap on by hand only—snug and seated, no tools needed.

Replacement is straightforward and inexpensive. If the cap won’t tighten securely, if the seal is perished, or if there’s persistent oil weep around the filler area after cleaning, fit a new cap. Go for a genuine Subaru cap or a high-quality equivalent that matches the FB20 engine, so thread pitch, sealing surface, and heat resistance are right. After replacement, run the engine and check for leaks, then recheck after a short drive.

Common signs the oil cap needs attention include a light oil smell after driving, visible weeping around the cap, a loose or cross-threaded feel, or a rough idle after the cap was left off. If the cap is missing or damaged, avoid driving far—unfiltered air and oil splash aren’t worth the risk. Sorting an oil cap during routine servicing is a quick win for long engine life and tidy ownership.

• Where is the oil cap on a 2015 Subaru Impreza?
  It’s under the bonnet on top of the engine, marked with an oil can symbol. On the FB20 engine, it’s on the rocker cover and is easy to reach for checking or topping up oil.

• What happens if the oil cap is missing or broken?
  You can get oil spray in the engine bay, a strong oil smell, and potential idle issues from unmetered air entering the crankcase. Replace the cap before driving any distance.

• How tight should the oil cap be?
  Hand-tight only. Screw it down until it seats and stops, without using tools. Ensure the rubber seal is in good nick so it seals without over-tightening.