radiator cap AUDI A4 2008 B8 / 4.G Owners Manual

Instruments and warning/indicator lamps 12Warning symbol in instrument cluster

If the symbol
 lights up in the display, this means that either the
coolant temperature is too high or the coolant level is too low
⇒page 33.
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.
WARNING
•
Before opening the bonnet and checking the coolant level,
please observe the warning information on ⇒page 255, “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.Caution
•
Additional lights and other accessories in front of the air inlet
reduce the cooling effect of the radiator. At high outside tempera-
tures and high engine loads, there is a risk of the engine over-
heating.
•
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.
Rev counter
The rev counter indicates the number of engine revolu-
tions per minute.You should select a lower gear if the engine speed drops below
1500 rpm. The start of the red zone on the dial indicates the
maximum engine speed which may be used briefly when the engine
is warm and after it has been run in properly. However, it is advisable
to change up a gear or move the selector lever to “D” (or lift your
foot off the accelerator) before the needle reaches the red zone.
Caution
Never allow the rev counter needle ⇒page 11, fig. 2 to go into
the red zone on the dial for more than a very brief period: there is a
risk of damaging the engine. The start of the red zone on the dial is
different for some engine versions.
For the sake of the environment
Changing up a gear early will help you to save fuel and minimise
engine noise.
button
This button has a number of different functions.
A2
SET
Fig. 3 Instrument
cluster: SET button
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Driver information system33
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data easily when braking. This could cause the tail of the vehicle to skid
sideways. Drive carefully to the nearest qualified workshop and
have the fault rectified.
Note
The warning lamp
 in the instrument cluster will start flashing as
well if there is a fault in the brake system.
Fault in the cooling system

Faults in the cooling system must be rectified immedi-
ately.If the
 symbol flashes in the display, this means that
either the coolant temperature is too high or the coolant
level is too low. The symbol is accompanied by a driver
message giving you more information about the fault. This
message will disappear after about 5 seconds, but you can
call it up again at any time by pressing the button:
Switch off engine, check coolant level
–Stop the vehicle.
– Switch off the engine.
– Check the coolant level ⇒page 261.
– Add more coolant if necessary ⇒page 261.
– Wait for the symbol to go out before driving on.
– Obtain professional assistance if necessary.
If the coolant level is correct, the overheating may be caused by a
malfunction of the radiator fan.If the alternator warning lamp lights up as well ⇒page 32, it is
possible that the drive belt has broken.
WARNING
•
If your vehicle should break down for technical reasons, stop it
at a safe distance away from moving traffic, switch off the engine
and turn on the hazard warning lights ⇒page 61, “Hazard
warning lights ”.
•
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.
•
The engine compartment of any motor vehicle is a dangerous
place. Before carrying out any work in the engine compartment,
switch off the engine and allow it to cool down. Please observe the
important safety warnings ⇒page 255, “Working on components
in the engine compartment”.Caution
Do not drive on if the symbol
 has come on to indicate a fault in
the cooling system, otherwise there is a risk of damaging the
engine.
Engine oil pressure too low

If the engine oil pressure is too low the fault must be recti-
fied immediately.If the

symbol flashes in the display, the oil pressure is
too low. The symbol is accompanied by a driver message
giving you more information about the fault. This message
WARNING (continued)
SET
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Checking and topping up fluids255
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Working on components in the engine compartment
Extra caution is necessary when working on components
in the engine compartment.Always be aware of the danger of injury and scalding as well as the
risk of accident or fire when working in the engine compartment
(e.g. when checking and refilling fluids). Always observe the warn-
ings listed below and follow all normal safety precautions. The
engine compartment of any motor vehicle is a potentially
hazardous area. ⇒.
WARNING
•
Switch off the engine.
•
Remove the ignition key.
•
Apply the parking brake.
•
Put the gear lever in neutral or selector in P.
•
Wait for the engine to cool down.
•
Keep children away from engine compartment.
•
Never spill fluids on hot engine components. These fluids can
cause a fire (e.g. radiator anti-freeze).
•
Take care not to cause short circuits in the electrical system,
especially when working on the battery.
•
Do not touch the radiator fan when the engine is hot. The fan
may start running suddenly.
•
Do not unscrew the cap on the expansion tank when the engine
is hot. The cooling system is under pressure.
•
Protect face, hands and arms by covering the cap with a large,
thick rag to protect against escaping coolant and steam.
•
If any tests have to be performed with the engine running,
there is an extra safety risk from the rotating parts, such as the
drive belts, alternator and radiator fan, etc., and from the high-
voltage ignition system.
•
Vehicles with automatic gearbox: Never open the throttle inad-
vertently (for instance by hand from the engine compartment) if a
gear is engaged while the vehicle is stationary with the engine
running. The vehicle could otherwise start moving immediately
and possibly cause an accident.
•
Observe the following additional warnings if work on the fuel
system or the electrical system is necessary:
−Always disconnect the battery.
−Do not smoke.
−Never work near naked flames.
−Always keep an approved fire extinguisher immediately
available.Caution
When topping up fluids make sure the correct fluid is put into the
correct filler opening. This can otherwise cause serious malfunc-
tions or engine damage.
For the sake of the environment
Inspect the ground underneath your vehicle regularly so that any
leaks are detected at an early stage. If you find oil spots or other
fluids, have your vehicle inspected by a qualified workshop.
Note
On right-hand drive vehicles* some of the containers / reservoirs
mentioned below are located on the other side of the engine
compartment.
WARNING (continued)
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Checking and topping up fluids 256Closing the bonnet– To close the bonnet, pull it down to overcome the spring
pressure.
– Then let it drop into the catches; do not press down ⇒.
WARNING
•
For safety reasons the bonnet must always be completely
closed when the vehicle is moving. After closing it always check
that it is properly secured. The bonnet must be flush with the adja-
cent body panels.
•
Should you notice that the bonnet is not safely secured when
the vehicle is moving, stop the vehicle immediately and close the
bonnet properly, otherwise it could cause an accident.
Engine compartment layoutEngine compartment layout
Main components for checking and refillingFig. 252 Typical locations of fluid containers, engine oil dipstick and engine oil
filler cap
Jump-start terminal (+) under a cover . . . . . . . . . . . . .
Brake fluid reservoir (
) . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil filler cap (

) . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil dipstick* (orange) . . . . . . . . . . . . . . . . . . . . .
Radiator expansion tank () . . . . . . . . . . . . . . . . . . . . .
Jump-start terminal (-) with hexagon head . . . . . . . . .
Windscreen washer container (
) . . . . . . . . . . . . . . . .
Hydraulic fluid reservoir for power steering . . . . . . . .
A1
265, 294
A2
262
A3
259
A4
258
A5
261
A6
265, 294
A7
267
A8
225
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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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Checking and topping up fluids267
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Windscreen washerPlain water on its own is not sufficient for the windscreen
washer system.The container for the windscreen washer
 contains the cleaning
fluid for the windscreen and the headlight washer system*
⇒fig. 260. Container capacity: ⇒page 321.
Plain water on its own is not enough to clean the glass properly. It
is therefore advisable to add a suitable washer fluid additive (with
wax solvent) to the water. A washer fluid with freeze-resistant addi-
tive should be used in winter.
Caution
•
Never put in radiator anti-freeze or other additives.
•
Never use washer fluid which contains paint thinners or solvents
as it can damage the paintwork.
Fig. 260 Engine
compartment: Wind-
screen washer
container
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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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