Parts for your 2020 Volkswagen Amarok-Radiator cap

2020 Volkswagen Amarok radiator cap – is there one?

Short answer: no, the 2020 Volkswagen Amarok doesn’t use a traditional radiator cap on the radiator. Instead, it runs a sealed cooling system with a pressurised coolant expansion tank (the translucent reservoir under the bonnet) and a screw-on pressure cap. That cap is the system’s pressure relief and sealing point.

This isn’t guesswork. Volkswagen’s 2020 Amarok Owner’s Manual talks about opening only the coolant expansion tank cap when the engine is cold, with no mention of a radiator cap. The factory Workshop Manual (Elsa/ERWIN) for the 3.0 V6 TDI cooling system diagrams the radiator without a service cap and designates the expansion tank cap as the pressure valve. VW’s genuine parts catalogue (ETKA) lists the expansion tank and its cap, but no separate radiator cap for the 2020 Amarok.

Why the change from old-school radiator caps? Modern VAG cooling systems push the pressure regulation and filling point to the expansion tank. That gives more consistent coolant levels in the radiator, better deaeration via bleed lines to the tank, improved packaging at the front end, and a safer, cleaner top-up point that’s easy to reach.

• Pressure control happens at the expansion tank cap, typically around 1.2–1.5 bar depending on the part revision.
• Filling and bleeding are done at the reservoir, not at the radiator.
• The radiator itself is a sealed unit with no service cap.

What should an Amarok owner or tech keep an eye on? Treat the expansion tank cap as the “radiator cap” for all practical purposes. If there’s a sweet coolant smell after shutdown, visible crust around the cap, staining on the tank, or hoses that feel collapsed after cool-down, the cap’s seal or valve may be tired. Replace the cap with the exact spec listed for the Amarok’s VIN to maintain the correct pressure rating.

Only open the cap when the engine is stone cold. Use the VW-approved coolant (per the under-bonnet label/Owner’s Manual, e.g., G12evo or the current supersession) mixed correctly with demineralised water if concentrate is used. If coolant loss continues after a new cap, pressure-test the system and check common leak points such as the tank, hose junctions, water pump, and EGR cooler lines.

• Does a 2020 Amarok have a radiator cap?
  It doesn’t have a cap on the radiator itself. The pressure cap lives on the coolant expansion tank and does the job of sealing and pressure control for the entire system. That’s the cap to check, service, or replace as needed.
• What pressure should the Amarok’s coolant cap be, and when should it be replaced?
  The spec varies by part revision (roughly 1.2–1.5 bar). Use the cap specified for the vehicle’s VIN. Replace it if the O-ring is cracked, there’s dried coolant around the cap, hoses feel unusually soft or collapse after cooling, or if there’s recurring coolant loss with no visible leaks.
• Where do you top up coolant on a 2020 Amarok?
  Top up only at the expansion tank, never at the radiator. Open the cap when the engine is cold, fill to the “MAX” mark with VW-approved coolant, and refit the cap firmly. If a large amount is added, a proper bleed per the workshop procedure is a good idea.