Checking coolant levelChecking coolant level  - Cooling system - Checking and topping up fluids - General maintenance - Audi S5 Owner's Manual - Audi S5

The coolant level can be checked at a glance.

Fig. 215 Engine compartment: Markings on radiator expansion tank
Fig. 215 Engine compartment: Markings on radiator expansion tank

Ц Switch off the ignition.
Ц Read off coolant level on radiator expansion tank ⇒ fig. 215. When the engine is cold it should be between the УMINФ and УMAXФ marks. When the engine is hot it may be slightly above the УMAXФ mark.

The coolant level should be checked with the engine switched off.

The coolant level is monitored by a warning lamp in the instrument cluster. However, we recommend that it should be checked occasionally.

Coolant losses

Any loss of coolant normally indicates a leak in the cooling system.

In this case the cooling system should be inspected by a qualified workshop without delay. It is not sufficient merely to top up the coolant.

If there are no leaks in the system, a loss of coolant can only occur if the coolant boils and is forced out of the system as a result of overheating.

Radiator sealants must not be added to the coolant. Such additives could seriously impair the function of the cooling system.