Parts for your 2016 Subaru Impreza-Oil cap

2016 Subaru Impreza oil cap — what it does and how to look after it

Yes, the 2016 Subaru Impreza is fitted with an engine oil filler cap. Technical sources back this up: the 2016 Impreza Owner’s Manual (Subaru Corporation, Engine Oil section) instructs the driver to remove and refit the oil filler cap when checking or topping up oil, and the Subaru FAST/OEM parts catalogue lists a dedicated “Cap – Oil Filler” for the FB20 engine used in this model. So it’s absolutely a relevant service item on this car.

On the 2016 Impreza, the oil cap seals the top of the engine’s oil filler neck under the bonnet. Its job is simple but vital: keep contaminants out, keep engine oil in, and maintain proper crankcase sealing so the PCV system can do its thing. A sound cap helps prevent oil mist and splatter on the rocker cover, reduces the chance of burning-oil smells, and avoids unmetered air sneaking into the crankcase that could upset idle quality or fuel trims.

For servicing, the cap should be treated as a small but important consumable. Each oil change, give the cap a quick once-over. Check the plastic body for heat-related cracking and make sure the O-ring or gasket isn’t flattened, brittle, or torn. Wipe any sludge off the threads and sealing face, then refit by hand until it’s snug — no need to lean on it with tools. If the cap is loose, missing, or the seal is perished, expect weeping oil, dust ingress, and a messy engine bay.

Replacement is straightforward and inexpensive. If the O-ring is available separately, swapping just the seal can restore a proper fit, otherwise, a complete cap is the go. Sticking caps often free up with a clean rag for grip — avoid pliers that can crack the plastic. Because Subaru used different caps across engines and years, it pays to match by VIN or engine code (FB20) to ensure the correct profile and seal height. Genuine or high-quality aftermarket is recommended to maintain the right fit and durability through Aussie and Kiwi conditions.

• Inspect the cap and O-ring every service (10,000–15,000 km or annually).
• Clean and hand-tighten only, don’t overtighten.
• Replace at the first sign of cracking, warping, or persistent oil mist.

Popular questions about the 2016 Subaru Impreza oil cap

What are the signs the oil cap needs replacing?
Common giveaways include visible oil mist around the filler neck, a perished or flattened O-ring, cracking in the plastic, or a cap that no longer tightens positively. Some drivers also notice more engine-bay odour after a drive. If cleaning and refitting doesn’t sort it, it’s time for a new cap or seal.

Can they drive if the oil cap is missing?
It’s not recommended. Without the cap, oil can spurt out and contaminants can be drawn in. The engine may run a bit off due to crankcase ventilation changes, and you’ll likely end up with a messy rocker cover. If the cap’s gone missing, fit a proper replacement before driving any distance.

Does the cap have a separate gasket or O-ring?
Yes, most 2016 Impreza caps use an O-ring style seal. Depending on supplier, the O-ring may be sold separately, but many owners choose to replace the complete cap to ensure the plastic body and seal are both fresh and heat-resistant for the long haul.