Parts for your 2010 Holden Captiva 5-Radiator cap

2010 Holden Captiva 5 — Radiator Cap Relevance

Based on technical sources, the 2010 Holden Captiva 5 does not use a traditional radiator-mounted cap. Instead, it runs a sealed, pressurised cooling system with a cap on the coolant surge (expansion) tank. The Holden Captiva CG Owner’s Manual (2010) identifies a coolant surge tank and cautions against opening its cap when hot, with no mention of a filler cap on the radiator. GM Global Service Information for Captiva/Antara models describes the “coolant surge tank cap” as the system’s pressure control point. Local parts catalogues likewise list a surge tank cap for Captiva CG models, not a radiator cap.

That makes a “radiator-cap” part not applicable for the 2010 Captiva 5. Under the bonnet, the radiator itself is a closed unit, filling and pressure regulation happen via the remote surge tank. Owners and workshops should therefore look for and service the coolant surge tank cap rather than searching for a radiator cap that isn’t fitted.

• Packaging and serviceability: A remote surge tank creates a single, high-fill point that’s easy to access and helps purge air, so the radiator doesn’t need its own cap.
• System performance: The surge tank design improves coolant deaeration and maintains stable pressure across the system, aiding pump efficiency and temperature control.
• Reliability and emissions: Fewer openings on the radiator reduce potential leak points and support a fully sealed system, helping coolant longevity and reducing evaporative loss.

Maintenance tip: Treat the surge tank cap as the pressure cap for the whole system. Inspect its seal and spring for damage, ensure the cap threads and tank neck are clean, and replace the cap if the rubber hardens, cracks, or if there are signs of pressure loss (coolant smell, staining, frequent top-ups). Only remove the cap when the engine is completely cool, and refill with the correct, manufacturer-approved coolant mix to the “COLD” mark on the tank.

Technical sources referenced: Holden Captiva CG Owner’s Manual (2010, cooling system and engine compartment sections), GM Global Service Information (Cooling System Description and Operation for Captiva/Antara, CG series), Australian parts catalogues listing a coolant surge tank cap for Holden Captiva CG (no radiator-mounted cap).

Does a 2010 Holden Captiva 5 have a radiator cap?

No. This model uses a sealed cooling system with a pressurised cap on the coolant surge (expansion) tank, not on the radiator itself. The radiator is a closed unit without a service cap.

Where should coolant be topped up on a 2010 Captiva 5?

Top up at the coolant surge tank under the bonnet. Fill only when the engine is cool, and bring the level to the “COLD” mark. Use the manufacturer-recommended coolant type and concentration for best corrosion protection and temperature control.

What pressure cap does the Captiva 5 use, and when should it be replaced?

The surge tank cap is a pressure cap (often around 140 kPa/20 psi, but check the cap label or owner’s manual). Replace it if the rubber seal is cracked or hard, if the spring feels weak, or if there are signs of pressure loss like staining, coolant odour, or repeated low levels.