Coolant temperature gaugeCoolant temperature gauge  - Instruments - Instruments and warning/indicator lamps - Controls - Audi S5 Owner's Manual - Audi S5

The coolant temperature gauge only works when the ignition is switched on. In order to avoid possible damage to the engine, please read the following notes for the different temperature ranges.

Engine cold

If the needle is still in the lower range of the dial, this indicates that the engine has not yet reached operating temperature. Avoid high engine speeds, full acceleration and heavy engine loads.

Normal temperature

In normal operation the needle will settle somewhere in the centre of the dial once the engine has reached operating temperature. The needle may also go further up when the engine is working hard at high outside temperatures. This is no cause for concern provided the warning symbol does not start flashing. in the display does not start flashing.

symbol in instrument cluster WARNING symbol in instrument cluster If the symbol  lights up in the

If the symbol display, this means that either the lights up in the display, this means that either the coolant temperature is too high or the coolant level is too low.

If the needle is at the top end of the dial, this means the coolant temperature is too high. Stop the vehicle, switch off the engine and wait for it to cool down. If the warning lamp starts flashing again after just a short distance, contact a qualified workshop.

Before opening the bonnet and checking the coolant level, please observe the warning information Working on components in the engine compartment.
Never open the bonnet if you can see or hear steam or coolant escaping from the engine compartment; there is a risk of being scalded. Wait until you can no longer see or hear escaping steam or coolant.

Additional lights and other accessories in front of the air inlet reduce the cooling effect of the radiator. At high outside temperatures and high engine loads, there is a risk of the engine overheating.
The front spoiler also ensures proper distribution of the cooling air when the vehicle is moving. If the spoiler is damaged this can reduce the cooling effect, which could cause the engine to overheat.
You should obtain professional assistance.