Parts for your 2013 Ford Fiesta-Radiator cap

2013 Ford Fiesta radiator cap — what it really uses

Short answer: a traditional radiator cap on the radiator isn’t used on the 2013 Ford Fiesta. Ford’s own technical information (2013 Ford Fiesta Owner’s Manual, Cooling System section) and workshop literature for the 1.6L Duratec Ti‑VCT cooling system confirm the Fiesta runs a sealed, pressurised system with the pressure cap mounted on the plastic coolant expansion/degas reservoir, not on the radiator itself. Ford parts catalogues for WS/WZ Fiesta list a “coolant expansion tank cap”, not a radiator-neck cap. So when people say “radiator cap” for this model, they’re really talking about the reservoir’s pressure cap.

Why no old-school radiator cap? It’s about safety, packaging, and cooling efficiency. A sealed degas bottle lets the system purge air continuously, keeps coolant under stable pressure to raise the boiling point, and puts the only service cap high in the engine bay where it’s easy to reach and away from the hot core. The aluminium radiator is a closed unit with no service neck, which also reduces leak points and simplifies assembly. It’s the same logic used across most modern Fords.

What does this mean for maintenance? Treat the reservoir cap as the pressure cap that does the job of the “radiator cap”. Only remove it when the engine is stone cold. If there’s any doubt, wait, or wrap the cap with a rag and crack it slowly to ensure there’s no pressure.

• Inspection tips (every service or 10,000–15,000 km): check the cap’s rubber seals for nicks, flattening, or cracks, make sure the spring-loaded valve moves freely, look for white crust or coolant staining around the reservoir neck, and confirm the threads are clean.
• Symptoms of a tired cap: repeated coolant loss or overflow, sweet coolant smell after driving, hoses collapsing as the engine cools, sluggish cabin heat, or creeping temps on climbs and in traffic.
• Testing and replacement: a shop can pressure-test the cap with an adapter. If it can’t hold the specified pressure (the exact kPa/psi rating is printed on the cap and listed in the owner’s manual), replace it. Fit a quality cap that meets Ford’s spec and rating. Hand-tighten firmly, don’t overdo it on the plastic neck.
• Coolant top-ups: use the Ford‑approved coolant type and mix specified in the owner’s manual. Fill to the “MAX” mark when cold, run the engine to operating temp with the heater on hot, let it cool, and recheck the level.

Keeping a healthy pressure cap on the Fiesta prevents boil-over, reduces hot spots, and helps the water pump and thermostat do their jobs. It’s an inexpensive part that protects a very expensive system.

FAQs

Where is the radiator cap on a 2013 Ford Fiesta?
There isn’t a cap on the radiator itself. The pressure cap is on the plastic coolant expansion (degas) reservoir. That’s the one to open for topping up or testing—only when the engine is cold.

What pressure rating cap does a 2013 Fiesta use?
The cap’s rating is printed on the top and listed in the owner’s manual. It’s typically around the 140 kPa/20 psi mark, but always match the exact rating shown for the vehicle.

Can a bad cap cause overheating or coolant loss?
Yes. If the cap can’t hold pressure, the coolant can boil sooner and push into the overflow, leading to loss, hot running, and aeration. If it sticks shut, hoses can collapse as the engine cools. Replacing a suspect cap is cheap insurance.