Parts for your 2013 Toyota Wish-Radiator cap

2013 Toyota Wish radiator-cap — what it does and how to look after it

Based on Toyota’s technical literature and parts catalogues, the 2013 Toyota Wish (ZGE2# series with 2ZR‑FAE or 3ZR‑FAE engines) is fitted with a radiator cap and it’s absolutely relevant to the cooling system. Toyota’s Electronic Parts Catalogue lists “Cap, Radiator” for these models (typical genuine references include 16401‑31650/31670, 1.1 bar), and the Toyota Repair Manual for the ZGE20-series includes an “On‑vehicle inspection – Radiator Cap” procedure using a tester to verify opening pressure around 1.1 bar. OEM DENSO radiator assemblies for the Wish also show a filler neck designed for a cap. That all confirms the cap is part of the system, not a decorative extra.

On the 2013 Wish, the radiator cap seals and pressurises the coolant circuit. By holding about 1.1 bar, it raises the boiling point so the engine can run efficiently on hot days and steep climbs without boiling over. Its two-way valve lets expanding coolant move into the overflow bottle as things heat up, then draws it back as the engine cools, keeping air out and the system topped up.

Because the cap is a pressure device, its spring, seals and seat need to be in good nick. As part of regular servicing, it should be checked for perished rubber, corrosion on the seat, weak spring action and smooth operation to the first detent. A quick pressure test with a cap tester is ideal. If the cap can’t hold the specified pressure, it’s time for a replacement.

• Recommended spec: use a 1.1 bar (approx. 108 kPa) cap to Toyota’s spec. Stick with a genuine cap or a quality equivalent from a reputable brand.
• Inspection cadence: check at every service. Replace with the cooling system service or at about 5–7 years/100,000–150,000 km, or sooner if it fails testing.
• Handling: only remove the cap when the engine is stone cold. Under the bonnet, twist to the first stop to vent any residual pressure, then remove.
• Coolant care: the Wish uses Toyota Super Long Life Coolant (pink). Keep the overflow bottle between “FULL” and “LOW”, and top up with the correct coolant mix.
• Watch for symptoms: repeated coolant loss with no obvious leak, collapsed upper hose after cool-down, overflow bottle staying full or bone dry, fluctuating temps, weak cabin heat — all can point to a tired cap.

When fitting a new cap, inspect the filler neck for nicks or corrosion, lightly wet the new seal with coolant for a smooth fit, and ensure the seating surface is clean so the cap can hold pressure properly.

Popular questions about the 2013 Toyota Wish radiator-cap

What pressure radiator cap suits a 2013 Toyota Wish?
The 2013 Wish uses a 1.1 bar cap (about 108 kPa), as shown in Toyota parts listings for ZGE2# models. Using the correct rating helps maintain the designed boiling point and recovery function. Genuine Toyota caps (e.g., 16401‑31650/31670) or high-quality equivalents that clearly state 1.1 bar are the safe bet.

Where is the radiator cap on a 2013 Toyota Wish?
It’s typically on the radiator’s upper tank under the bonnet, with the translucent overflow bottle nearby. On some market variants there may be a short remote filler neck, but the cap is still on the pressurised side of the system and serviced the same way — only when cold.

How often should the radiator cap be replaced?
It should be inspected at every service and replaced if it fails a pressure test or shows wear. As a preventative move, many workshops swap it during a coolant service or at roughly 5–7 years/100,000–150,000 km to keep the cooling system reliable.