Parts for your 2018 Subaru Exiga-Radiator cap

2018 Subaru Exiga radiator cap

Based on technical sources—the Subaru Factory Service Manual for the YA-series Exiga/Crossover 7 (Cooling System section) and the Subaru Electronic Parts Catalogue for MY2018—the 2018 Subaru Exiga does use a pressure cap (commonly called a radiator cap). It’s fitted to the pressurised coolant filler/header tank near the top of the engine, rather than on the radiator itself. The radiator core doesn’t have a filler neck, the cap on the header tank is the system’s pressure control point.

On the 2018 Subaru Exiga, the radiator cap’s main job is to keep the cooling system at the right pressure, which lifts the coolant’s boiling point so it can carry more heat without boiling under the bonnet. It also manages coolant movement between the pressurised header tank and the overflow bottle as the engine heats and cools, thanks to its two-way valve design. That little cap protects hoses, the heater core and the water pump from pressure spikes and air ingestion, helping the FB-series engine run cool and consistent on Aussie and Kiwi roads.

Location-wise, owners will find the cap perched on the alloy/plastic header tank up high in the engine bay. Even though it’s not on the radiator, it’s the same service item most folks call a radiator cap—same function, different spot.

Good servicing habits keep this part out of sight and out of mind. Here’s how they’ll stay on top of it:

• Only inspect or remove the cap when the engine is stone cold. A hot system can spray scalding coolant.
• At every service (or at least annually), check for perished rubber seals, weak spring tension, corrosion, or dried coolant crust around the neck.
• Pressure-test the cap if there are any overheating niggles, coolant loss, or collapsed upper hoses after cool-down.
• Match the specified kPa rating stamped on the cap. Using the wrong rating can cause overheating or stress the system.
• Replace the cap whenever the coolant is changed, or every 3–5 years/60,000–100,000 km, whichever comes first, if condition is uncertain.

Symptoms of a dodgy cap include gradual coolant loss into the overflow bottle, gurgling after shut-down, fluctuating temp on long climbs, or hoses that suck flat as the engine cools. When fitting a new cap, top up with the correct Subaru long-life coolant and bleed the system per the service manual to avoid air pockets. It’s a cheap part that quietly safeguards the Exiga’s cooling system day in, day out.

Popular questions about the 2018 Subaru Exiga radiator cap

Where is the radiator cap on a 2018 Subaru Exiga?
It sits on the pressurised coolant filler/header tank at the top of the engine bay, not on the radiator itself. Subaru routes filling and pressure control through this high-mounted tank for reliable air purging and stable system pressure.

What pressure rating should the cap be?
Use the rating specified for the exact engine/market variant, as shown on the existing cap or in the factory service info. Many Exiga/Crossover 7 models use a cap around the 1.1 bar (approx. 108–110 kPa) range, but owners should match the marking on their vehicle rather than guessing.

How often should the cap be replaced?
Inspect it at each service and replace it if the seal is perished, the spring feels weak, or there are signs of leakage. As a preventative step, swapping it every 3–5 years or when changing coolant is sensible, especially if the vehicle does lots of kilometres or towing.