Parts for your 2022 Honda Civic-Radiator cap

2022 Honda Civic radiator cap — what’s the go?

For the 2022 Honda Civic (FE series), a traditional radiator cap on the radiator itself isn’t used. Instead, the Civic runs a sealed, pressurised expansion/degas tank with its pressure cap mounted on the plastic reservoir. This layout is shown in Honda’s service information cooling-system diagrams for the 2.0L and 1.5L turbo engines, noted in the 2022 Civic Owner’s Manual where checks are directed at the reserve tank and its cap, and reflected in the Honda Electronic Parts Catalogue listings that show the radiator assembly without a cap while the cap is specified on the reservoir tank.

Why the change? Modern cooling systems are designed to purge air continuously via a high-mounted degas bottle, improving coolant circulation, warm-up speed and temperature stability—especially important on downsized, turbocharged engines. Mounting the pressure cap on the expansion tank, not the radiator, puts the fill/bleed point at the system’s highest spot under the bonnet, helping air separation and reducing hot spots. It also tidies packaging for today’s low bonnet lines and large crash structures, and it’s safer for owners—there’s no temptation to crack a scalding-hot radiator neck.

What this means for owners is simple: if they’re searching for a “radiator cap” on the radiator, they won’t find one. The functional “cap” to care for is the coolant reservoir’s pressure cap. Stick to Honda Type 2 (blue) coolant, and only open the cap when the engine is stone cold.

• Signs the reservoir cap may be tired: coolant weeping around the cap, hoses going rock-hard quickly after shut-down, frequent coolant loss, or overheating with no obvious leaks.
• Good practice: have the cap’s pressure rating checked during servicing, replace it if the seal is cracked or the spring feels weak, and keep the coolant at the MAX line when cold.
• Always use a cap that meets the factory pressure spec (typically around 1.1 bar) for the FE-series Civic.

Bottom line: the 2022 Civic absolutely has a pressure cap—but it lives on the expansion tank, not the radiator.

Popular questions

Does the 2022 Honda Civic have a radiator cap?
No—there’s no cap on the radiator itself. The pressure cap is on the coolant expansion (reserve) tank. That’s the one to inspect, pressure-test and replace if needed.

Where do you add coolant on a 2022 Civic?
Top up at the expansion tank under the bonnet, and only when the engine is completely cool. Fill to the MAX mark with Honda Type 2 coolant or an equivalent that meets the same spec.

When should the coolant cap be replaced?
Replace it if it fails a pressure test, the rubber seal looks perished, or if there are repeated coolant losses with no visible leaks. Many workshops will test or proactively replace it around major cooling-service intervals.