2009 Audi Q5 / SQ5 — Owner's Manual
Before winter sets in, have the coolant checked to see if the coolant additive in your vehicle is sufficient to meet the climate conditions. This is especially important if you live in a region where the winter is extremely cold. If necessary, increase the proportion of coolant additive to 60%. When adding coolant additive to your cooling system, remember: We recommend using only coolant additive G12++ (check the label) for your vehicle.
This coolant additive is available at authorized dealers. Other types of antifreeze can significantly reduce corrosion protection. The resulting corrosion can cause a loss of coolant and serious engine damage. Do not add any type of radiator leak sealant to your vehicle's engine coolant.
Adding radiator repair fluid may adversely affect the function and performance of your cooling system and could result in damage not covered by your New Vehicle Limited Warranty. The location of the coolant expansion tank can be seen in the engine compartment illustration => page 262. To obtain an accurate reading, the engine must be switched off. The expansion tank in your vehicle is equipped with an electric coolant level sensor.
When the coolant level is too low, the warning light in the AutoCheck System - page 30 will blink until you add coolant and the level has been restored to normal. Even though there is an electric coolant level sensor, we still recommend you check the coolant level from time to time. Coolant loss may indicate a leak in the cooling system. In the event of coolant loss, the cooling system should be inspected immediately by your authorized dealer.
It is not enough merely to add coolant. In a sealed system, losses can occur only if the boiling point of the coolant is exceeded as a result of overheating.