Parts for your 2014 Subaru Impreza-Radiator cap

2014 Subaru Impreza radiator cap — what it does and how to look after it

Per Subaru technical literature for the FB20-powered 2014 Impreza — including the Owner’s Manual cooling-system cautions and the factory service manual — this model absolutely uses a pressure radiator cap. It’s typically fitted on the engine’s coolant reservoir/degas tank rather than directly on the radiator neck, which is why some owners don’t spot it at first glance. That pressurised cap is a key part of the closed cooling system, managing pressure to raise the coolant’s boiling point and allowing hot coolant to purge air and expand safely.

The cap’s spring-and-valve arrangement holds a set pressure (commonly around 1.1 bar for Subaru genuine caps), then releases excess pressure to the overflow when the engine’s hot, and draws coolant back as it cools. If the cap’s seal or spring weakens, it can cause higher temps, coolant loss, or hard cold starts from air being pulled into the system. So while it’s a small bit of kit, it’s doing a big job.

As part of routine servicing on a 2014 Subaru Impreza, a quick radiator-cap check is well worth it. Inspect the rubber seals for nicks, flattening, or cracking, look for dried white residue that hints at weeping, and confirm the pressure rating matches factory spec. A cooling-system pressure test or a cap-specific tester can verify the cap’s hold and relief pressures. Many workshops treat the cap as a condition-based item — if it fails a test or shows obvious wear, replace it. As a rule of thumb for local conditions, swapping the cap every 5–7 years or 80–100,000 km isn’t a bad shout, especially if the vehicle sees hot summers, towing, or lots of stop-start commuting.

Only open the cap stone cold — never when hot or even warm. When topping up, use the correct Subaru-approved premix coolant and keep the reservoir at the indicated marks. Clean the filler neck before refitting the cap, and make sure it clicks home firmly.

• Signs it’s time: rising temps on hills, coolant smell, low reservoir after short trips, or crunchy/loose cap feel.
• Best practice: genuine or quality OEM-equivalent cap at the specified pressure rating to maintain the system’s design margins.

Popular questions

Does a 2014 Subaru Impreza have a radiator cap, and where is it?
Yes. On most 2014 Imprezas it’s on the pressurised coolant reservoir (degas tank) near the top of the engine, not on the radiator itself. It looks like a metal cap with warning text — only remove it when the engine is completely cold.

What pressure rating cap does a 2014 Impreza use?
Subaru genuine caps for this model are typically rated around 1.1 bar (approx. 108 kPa). Always match the rating shown in the owner’s manual or parts catalogue, or use a quality OEM-equivalent with the same spec.

How often should the radiator cap be replaced?
It’s condition-based. Inspect at each service, replace if it fails a pressure test or shows seal damage. As a preventive measure, many techs replace the cap every 5–7 years or 80–100,000 km, especially in hotter Aussie and Kiwi climates.