Audi S5 Owner's Manual page 228

document_0900452a81793dcc.book Seite 226 Mittwoch, 21. März 2007 5:42 17
226 Checking and topping up fluids
Caution
Radiator sealants must not be added to the coolant. Such additives
could seriously impair the function of the cooling system.
Topping up the coolant
Be careful when topping up coolant.
– Switch off the engine.
– Wait for the engine to cool down.
– Cover the cap on the expansion tank ⇒ page 225, fig. 215
with a cloth, and carefully unscrew the cap anti-clock-
wise ⇒
.
– Add coolant.
– Screw the cap on again tightly.
Make sure that the coolant meets the required specifications
⇒ page 224, "Coolant". Do not use a different type of additive if anti-
freeze additive G12+, G12 or G11 is not available. In this case use
only water and bring the coolant concentration back up to the
correct level as soon as possible by putting in the specified additive.
Always top up with fresh, unused coolant.
Do not fill above the "MAX" mark. Excess coolant is forced out of the
system through the valve in the filler cap when the engine gets hot.
If a lot of coolant has been lost, wait for the engine to cool down
before putting in cold coolant. Failure to do so could result in
serious engine damage.
WARNING
The cooling system is under pressure. Do not unscrew the cap
on the expansion tank when the engine is hot: you could be
scalded by escaping steam
The coolant and coolant additive can be a health hazard. Store
the coolant additive in the original container in a safe place out of
reach of children – risk of poisoning.
For the sake of the environment
Drained off coolant should not be used again. Drain off the used
coolant into a suitable container and dispose of it in the proper
manner (observe environmental regulations).
Radiator fan
The radiator fan can start running spontaneously.
The radiator fan is driven by the engine via a poly V-belt. The speed
of the fan is varied by a viscous clutch according to the temperature.
There is also an auxiliary electric fan, which cuts in automatically
whenever the temperature of the coolant and the engine compart-
ment rises above a certain level.
The auxiliary fan can continue to run for as long as 10 minutes after
stopping the engine – even after the ignition is switched off. It may
also start running suddenly ⇒
after a while if
residual heat raises the coolant temperature, or
the hot engine compartment is additionally heated up by the
sun.
WARNING
When working in the engine compartment be aware that the radi-
ator fan may start running suddenly – risk of injury.