cooling AUDI A4 2008 B8 / 4.G Owner's Guide

Checking and topping up fluids 260
Caution•
The oil level must never be above area ⇒page 258, fig. 254,
as this may result in damage to the catalytic converter or to the
engine. On vehicles without an oil dipstick, you can check the oil
level via the sound system or MMI*. Contact a qualified workshop to
extract the engine oil if necessary.
•
No additives should be used with engine oil. Any damage caused
by the use of such additives would not be covered by the factory
warranty.For the sake of the environment
•
Never pour oil down drains or into the ground.
•
Always observe statutory requirements when disposing of
empty oil canisters.
Cooling systemCoolant
The purpose of the coolant is to carry heat away from the
engine. The correct amount of anti-freeze is important to
prevent the cooling system from freezing in winter.The cooling system is filled for life at the factory, so the coolant does
not need to be changed. The coolant consists of a mixture of water
and anti-freeze additive G12++. This is a glycol-based anti-freeze
with anti-corrosion additives.
Anti-freeze additive
The amount of anti-freeze additive required depends on the temper-
atures to be expected in the winter season. If the anti-freeze concen-
tration is too low the coolant can freeze, resulting in failure of the
cooling system and heater.The cooling system is filled at the factory with the correct amount of
anti-freeze for the country concerned.
In most cases the mixture consists of 60% water and 40% additive.
This mixture gives the required anti-freeze protection at tempera-
tures down to -25 °C and protects the alloy parts of the cooling
system against corrosion. It also prevents scaling and raises the
boiling point of the coolant.
Countries with warm climate
The coolant concentration must not be reduced by adding plain
water, even in the summer or in warm climates. The concentration
of the anti-freeze additive must always be at least 40%.
Countries with cold climate
If greater anti-freeze protection is required in very cold climates, the
proportion of the anti-freeze additive G12++ can be increased. A
concentration of 60% offers protection down to about - 40 °C. The
concentration of the anti-freeze additive must not be more than
60%, otherwise this would reduce the anti-freeze protection. In addi-
tion, the cooling effect will be adversely affected.
Vehicles for export to countries with a cold climate (such as Sweden,
Norway and Finland) are supplied with antifreeze protection down
to about -35 °C. The concentration of the antifreeze additive for
these countries should always be at least 50%.
Caution
•
It is advisable to have the cooling system checked before the
winter season to make sure that the antifreeze concentration is
adequate for the conditions to be expected. This applies particularly
if you intend to take the car into a colder climate zone. If necessary,
have the anti-freeze concentration increased to 50 - 60% as required.
•
Use only anti-freeze additive G12++, an additive meeting the
specification “TL 774 G”. Other additives may give considerably
inferior corrosion protection. The resulting corrosion in the cooling
system can lead to a loss of coolant, causing serious damage to the
engine.
Aa
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Checking and topping up fluids261
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
The coolant additive G12++ can be mixed only with additives
G12+ and G12.
Checking coolant level
The coolant level can be checked at a glance.– Switch off the ignition.
– Read off coolant level on radiator expansion tank
⇒fig. 257. When the engine is cold it should be between
the “MIN” and “MAX” marks. When the engine is hot it
may be slightly above the “MAX” 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 ⇒page 33. 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.
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 ⇒fig. 257 with a
cloth, and carefully unscrew the cap anti-clockwise
⇒.
– Add coolant.
– Screw the cap on again tightly.Make sure that the coolant meets the required specifications
⇒page 260, “Coolant”. Do not use a different type of additive if anti-
freeze additive G12++, G12+ or G12 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.
Fig. 257 Engine
compartment: Mark-
ings on radiator expan-
sion tank
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Checking and topping up fluids 262
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.
Brake fluidChecking brake fluid level
The brake fluid level can be checked at a glance.– Check the fluid level on the brake fluid reservoir
⇒fig. 258. It should always be between the “MIN” and
“MAX” marks.In right-hand drive vehicles the brake fluid reservoir is on the other
side of the engine compartment.
The fluid level may drop slightly after a period of time due to the
automatic compensation for brake pad wear. This is quite normal.
However, if the level goes down noticeably in a short time, or drops
below the “MIN” mark, there may be a leak in the brake system. If
the fluid level in the reservoir is too low, this will be indicated by the
brake warning lamp ⇒page 32. If this should happen, take the car
to a qualified workshop immediately and have the brake system
inspected.
Fig. 258 Engine
compartment: Mark-
ings on brake fluid
reservoir
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Index 332CCapacities . . . . . . . . . . . . . . . . . . . . . . . . . 321
Car keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Care of vehicle . . . . . . . . . . . . . . . . . . . . . 244
Catalytic converter . . . . . . . . . . . . . . . . . . 229
Central locking system . . . . . . . . . . . . . . . 42
Boot lid . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Deadlock mechanism . . . . . . . . . . . . . . 48
Fuel tank flap . . . . . . . . . . . . . . . . . . . . 252
Locking . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Locking and unlocking the vehicle from
inside . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Manual locking . . . . . . . . . . . . . . . . . . . 51
Opening and closing windows . . . . . . 54
Sun roof . . . . . . . . . . . . . . . . . . . . . . . . . 54
Switches on driver's door . . . . . . . . . . 49
Unlocking . . . . . . . . . . . . . . . . . . . . . . . . 48
Cetane number . . . . . . . . . . . . . . . . . . . . . 251
Changing a wheel . . . . . . . . . . . . . . . . . . . 288
Changing bulbs
SeeBulbs . . . . . . . . . . . . . . . . . . . . . . . 304
Chassis number . . . . . . . . . . . . . . . . . . . . 321
Child safety . . . . . . . . . . . . . . . . . . . . . . . . 210
Side airbags . . . . . . . . . . . . . . . . . . . . . 212
Child safety seat . . . . . . . . . . . . . . . . . . . . 213
Child seat categories . . . . . . . . . . . . . 213
Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . 216
ISOFIX system . . . . . . . . . . . . . . . . . . . 218
On front passenger's seat . . . . . . . . . 211
Safety notes . . . . . . . . . . . . . . . . . . . . . 210
Child-proof catches
Rear doors . . . . . . . . . . . . . . . . . . . . . . . 53Cigarette lighter . . . . . . . . . . . . . . . . . . . . . 87
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Cleaning Alcantara . . . . . . . . . . . . . . . . . . 250
Cleaning seat covers
Alcantara . . . . . . . . . . . . . . . . . . . . . . . 250
Natural leather . . . . . . . . . . . . . . . . . . 249
Textile covers . . . . . . . . . . . . . . . . . . . . 247
Cleaning textile covers and trim parts . . 247
Clock, setting . . . . . . . . . . . . . . . . . . . . . . . 13
Closing
Bonnet . . . . . . . . . . . . . . . . . . . . . . . . . 256
Sun roof . . . . . . . . . . . . . . . . . . . . . . . . . 55
Coat hooks . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Colour code . . . . . . . . . . . . . . . . . . . . . . . . 321
coming home . . . . . . . . . . . . . . . . . . . . . . . 59
Compact temporary spare wheel
SeeSpare wheel . . . . . . . . . . . . . . . . . 284
Compartment for (sun)glasses . . . . . . . . . 91
Compass in mirror . . . . . . . . . . . . . . . . . . . 71
Controls and displays
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Convenience open/close function . . . . . . 54
Cooling system
Anti-freeze additive . . . . . . . . . . . . . . . 260
Checking coolant level . . . . . . . . . . . . 261
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . 260
Coolant temperature gauge . . . . . . . . . 11
Malfunction . . . . . . . . . . . . . . . . . . . . . . 33
Radiator fan . . . . . . . . . . . . . . . . . . . . . 262
Topping up coolant . . . . . . . . . . . . . . . 261Cruise control system
Adjusting stored speed . . . . . . . . . . . 126
Indicator lamp . . . . . . . . . . . . . . . . . . . . 19
Pre-selecting a speed . . . . . . . . . . . . . 127
Switching off . . . . . . . . . . . . . . . . . . . . 127
Switching on . . . . . . . . . . . . . . . . . . . . 125
See alsoadaptive cruise control . . . . 128
Cup holders . . . . . . . . . . . . . . . . . . . . . . . . . 85
Current fuel consumption . . . . . . . . . . . . . 25
DDate display . . . . . . . . . . . . . . . . . . . . . . . . . 13
Daytime running lights . . . . . . . . . . . . . . . 59
DCP
SeeDynamic gear control program . 166
Deactivating front passenger's airbag . . 208
Deadlock mechanism . . . . . . . . . . . . . . 42, 48
Defrosting windows . . . . . . . . . . . . . . 98, 106
Deluxe automatic air conditioner . . . . . . . 93
Air distribution . . . . . . . . . . . . . . . . . . . 97
Air outlets . . . . . . . . . . . . . . . . . . . . . . . . 99
Air outlets for rear passengers . . . . . . 99
Air recirculation mode . . . . . . . . . . . . . 97
Automatic mode . . . . . . . . . . . . . . . . . . 95
Basic settings . . . . . . . . . . . . . . . . . . . . 100
Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Controls . . . . . . . . . . . . . . . . . . . . . . . . . 94
Defrosting . . . . . . . . . . . . . . . . . . . . . . . 98
Description . . . . . . . . . . . . . . . . . . . . . . . 93
Economical operation . . . . . . . . . . . . . 100
Heated rear window . . . . . . . . . . . . . . . 98
Seat heating, front . . . . . . . . . . . . . . . 114
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Index 340
Cooling system . . . . . . . . . . . . . . . . . . 260
Defrosting windows . . . . . . . . . . . 98, 106
De-icing windows . . . . . . . . . . . . . . . . 246
Diesel . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Seat heating (deluxe automatic air
conditioner) . . . . . . . . . . . . . . . . . . . 114
Seat heating for rear seats . . . . . . . . 115
Snow chains . . . . . . . . . . . . . . . . . . . . 273
Tyres . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Windscreen washer . . . . . . . . . . . . . . 267
Winter tyres . . . . . . . . . . . . . . . . . . . . . . . . 272
Wiper blades
SeeWindscreen wipers . . . . . . . . . . . . 68
XXenon lights
Driving abroad . . . . . . . . . . . . . . . . . . . . 59
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