Parts for your 2014 Audi Q5-Radiator cap

2014 Audi Q5 radiator cap — what’s fitted and what to service

For the 2014 Audi Q5 (type 8R), a traditional radiator-mounted cap isn’t used. Audi’s factory workshop information (ElsaPro/ElsaWin for Q5 8R — Cooling system), the 2014 Q5 Owner’s Manual (coolant section), and the VAG parts catalogue (ETKA for Q5 8R, model year 2014) all depict a sealed cooling circuit that vents and is filled via a pressurised coolant expansion tank cap, not a cap on the radiator itself. No radiator-neck cap is listed for this vehicle in the OEM parts catalogue, instead, the only service cap in the circuit is the expansion tank cap.

Why the change from the old-school radiator cap? Audi routes the radiator to a remote expansion tank so the system can self-degas, keep the radiator sealed, and maintain a consistent fill level. Mounting the pressure cap on the expansion tank improves packaging under the bonnet, keeps the hottest components sealed, and makes top-ups and checks easier and safer.

So while shoppers might search “radiator cap” for a 2014 Q5, the part to inspect or replace is actually the coolant expansion tank cap. It’s a pressure-rated safety valve that holds system pressure to the specification and relieves excess pressure if needed. If that cap can’t hold pressure, the Q5 may run hot, push coolant out, or show a sweet coolant smell after a drive. If it can’t vent correctly, hoses can harden up or collapse as the engine cools.

• Check the cap during regular servicing: look for cracked plastic, a perished seal, or dried pink/purple residue around the threads or vent.
• If overheating, hard upper hose after cool-down, or coolant loss is noted, have the cap pressure-tested to the spec shown in OEM data for the vehicle.
• Only open the cap when the engine is stone cold. Opening a hot, pressurised system can cause scalding.
• Top up with the Audi-approved coolant (G12/G13 family) mixed to spec. Don’t mix unknown coolants.

There’s no fixed replacement interval for the expansion tank cap, it’s replaced on condition. Given the modest cost and the role it plays, many technicians treat a suspect cap as a “cheap insurance” item when chasing cooling quirks on a 2014 Q5.

Does a 2014 Audi Q5 have a radiator cap?
Not on the radiator. It uses a pressurised cap on the coolant expansion tank. This design is shown in the 2014 Q5 Owner’s Manual cooling section, Audi ElsaPro/ElsaWin workshop procedures, and ETKA parts listings for the Q5 8R.

Where does coolant go on a 2014 Q5?
Under the bonnet, into the translucent coolant expansion tank with the screw-on pressure cap. Only open it when cold, and fill with the correct Audi-approved coolant mix to the “MAX” mark.

When should the expansion tank cap be replaced?
Replace it if it fails a pressure test, shows cracked plastic or a damaged seal, or if there are symptoms like coolant smell, slow loss of coolant, or hoses collapsing after shut-down. There’s no time/kilometre interval — it’s on condition.