2008 AUDI A4 technical data

Checking and topping up fluids261
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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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Technical data
Changing brake fluid
When required, the brake fluid should be changed by a
competent mechanic with the proper equipment.Brake fluid gradually absorbs moisture from the atmosphere. If the
water content in the brake fluid is too high, this may cause corrosion
in the brake system over time. In addition, the boiling point of the
brake fluid will be considerably reduced. This could adversely affect
the braking ability in certain circumstances.
For this reason the brake fluid must be changed periodically.
Your vehicle's Service Schedule will tell you when the brake fluid has
to be changed.
It is advisable to have the brake fluid changed as part of a regular
Inspection Service at your Audi workshop. They are familiar with the
procedure and have the necessary special tools and spare parts as
well as the proper facilities for disposing of the old fluid.
Use only the genuine brake fluid specified by the factory Qualified
workshops know that the brake fluid “DOT 4” is approved by Audi.
The brake fluid must be fresh and unused.
WARNING
•
Brake fluid is poisonous; store it in the sealed original container
in a safe place out of reach of children.
•
Heavy use of the brakes may cause a vapour lock if the brake
fluid is left in the system for too long. This would seriously affect
the efficiency of the brakes and the safety of the car – risk of acci-
dent.Caution
Please note that brake fluid will attack the paintwork on contact.
For the sake of the environment
If the fluid has to be drained out of the brake system, use an appro-
priate container to catch the used brake fluid and dispose of it in the
proper manner.BatteryGeneral notes
All work on batteries requires specialist knowledge.The battery is virtually maintenance-free. It is checked as part of the
Inspection Service.
We recommend that you replace a battery once it is older than 5
years.
When an airbag is triggered, the battery will, under certain circum-
stances, be disconnected from the on-board power supply for
safety reasons ⇒ in “General notes on airbag system” on
page 201.
Disconnecting the battery
If the battery is disconnected, some of the vehicle's functions will
become inoperative (e.g. electric windows). These functions will
require resetting after the battery is reconnected. For this reason,
the battery should only be disconnected from the vehicle's electrical
system when absolutely necessary.
If the vehicle is not used for long periods
If you do not drive your vehicle for a period of several days or weeks,
the power management will gradually shut off the on-board
systems one by one, or reduce the amount of current they are using.
This limits the amount of power consumed and helps to ensure reli-
able starting even after a long period ⇒page 226.
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Technical data charges) when handling cables and electrical equipment. Never
cross the battery poles. The resulting high-energy sparks can
cause injury.
•
A highly explosive mixture of gases is given off when the
battery is under charge. Only charge battery in a well ventilated
area.
•
Keep children away from the battery and battery acid.
•
Switch off all electrical equipment before starting any work on
the vehicle electrical system. Remove the ignition key. The minus
cable of the battery must be disconnected. When changing a light
bulb, it is sufficient to only turn off the light.
•
Before disconnecting the battery, turn off the anti-theft
system! Otherwise, the alarm will sound.
•
When disconnecting the battery from the vehicle's electrical
system, first disconnect the minus cable and then the plus cable.
•
Before reconnecting the battery, turn off all electrical equip-
ment. First connect the plus cable, then the minus cable. The
battery cables must not be connected to the wrong battery poles
- serious risk of cable fire.
•
Never charge a frozen or thawed out battery - risk of explosion
and chemical burns! A battery must be replaced once it has been
frozen. When it is discharged the battery can freeze at tempera-
tures around 0°C.
•
Make sure that the vapour hose is always attached to the
battery.
•
Never use a damaged battery - risk of explosion! Replace a
damaged battery immediately.Caution
•
Never disconnect the car's battery with the engine running or
with the ignition turned on, otherwise the electrical system or elec-
trical components will be damaged.
•
Do not expose the battery to direct sunlight over a long period of
time, as the intense ultraviolet radiation can affect the battery
housing.
•
If the car is left standing for long periods, protect the battery
from extreme cold temperature so that it does not “freeze up” and
become damaged.
Charging the battery
Terminals for charging the battery are fitted in the engine
compartment.– Note the warnings ⇒ in “Important safety warnings
for handling a car battery” on page 264 and ⇒.
– Switch off all electrical equipment. Remove the ignition
key.
– Open the bonnet ⇒page 254.
– Open the red cap on the positive terminal ⇒fig. 259.
– Follow the correct procedure for connecting the charger
cables to the jump-start terminals (terminal with red cap
= “positive”, terminal with hexagon = “negative”).
WARNING (continued)
Fig. 259 Engine
compartment: Termi-
nals for jump leads and
battery charger
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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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Wheels and tyres269
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Technical data
– The tyre pressures should only be checked when the
tyres are cold. The slightly raised pressures of warm tyres
must not be reduced.
– The pressures must be altered to suit major changes in
the load being carried.
– Avoid fast cornering and hard acceleration.
– Inspect the tyres for irregular wear from time to time.Tyre pressure and vehicle loading
The tyre pressure must be adjusted according to the load the vehicle
is carrying. We recommend adhering to the tyre pressure specifica-
tions for a maximum load. The tyre inflation pressures are listed on
a sticker on the end face of the driver's door ⇒page 268, fig. 261.
However, if you prefer an extra-smooth ride and the vehicle is not
fully loaded, you can select the tyre pressure for a normal load (no
more than three people travelling in the vehicle). However, should
you wish to drive with a full load you must increase the tyre pressure
to the specified maximum.
Under-inflation or over-inflation will reduce the life of the tyres
considerably and also impair the car's handling. Correct inflation
pressures are very important, especially at high speeds. The pres-
sures should therefore be checked at least once a month and before
starting a journey.
Do not forget the spare wheel* when checking the tyre pressures.
Keep the spare tyre inflated to the highest pressure required for the
road wheels.
Driving habits
Fast cornering, heavy acceleration and hard braking (squealing
tyres) all increase tyre wear.Wheel balancing
The wheels on new vehicles are balanced. However, various factors
encountered in normal driving can cause them to become unbal-
anced, which results in steering vibration.
Unbalanced wheels should be rebalanced, as they otherwise cause
excessive wear on steering, suspension and tyres. A wheel must
also be rebalanced when a new tyre is fitted or if a tyre is repaired.
Incorrect wheel alignment
Incorrect wheel alignment causes excessive tyre wear, impairing the
safety of the vehicle. If you notice excessive tyre wear, contact your
Audi dealer.
WARNING
•
Always adapt the tyre pressure accordingly when the vehicle
load changes.
•
Under-inflated tyres flex more and can overheat at continuous
high speeds. This can cause tread separation and tyre blow-out,
which could result in an accident.For the sake of the environment
Under-inflated tyres will increase the fuel consumption.
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Technical data
– Never use tyres whose actual size exceeds the dimen-
sions of the factory-approved makes of tyre.
– If you wish to fit the vehicle with non-standard rims or
tyres, it is advisable to consult an Audi dealer before
purchasing them.The tyres and wheel rims are an essential part of the vehicle's
design. The tyres and rims approved by Audi are specially matched
to the characteristics of the vehicle and make a major contribution
to good roadholding and safe handling ⇒.
The sizes of the rims and tyres approved for your vehicle are listed
in the vehicle's documents (e.g. EC Certificate of Conformity or COC
document
3)). The vehicle documents vary depending on the
country of residence.
Understanding the tyre designations makes it easier to choose the
correct tyres. For example, radial ply tyres have the following tyre
designations marked on the sidewall:
225 / 50 R 17 94 Y
This contains the following information:
The manufacturing date is also indicated on the tyre sidewall
(possibly only on the inner side of the wheel):
DOT ... 1006...means, for example, that the tyre was produced in the 10th week of
2006.
Please note that with some types of tyres, the actual tyre size can
differ from the nominal size marked on the tyre (for instance 225/50
R 17 94 Y), and there may be significant differences in the contours
of the tyres, even though the tyres are marked with the same
nominal size designation. When replacing the tyres, it is therefore
important to make sure that the actual size of the new tyres does
not exceed the dimensions of the factory-approved makes of tyre.
Failure to observe this requirement can affect the clearance needed
for the tyres. This could result in contact between the tyres and
suspension components or bodywork. The brake lines could also be
damaged and the vehicle's safety could be severely impaired ⇒.
When using tyres with the maximum permitted nominal dimen-
sions, this can also void the vehicle's registration.
If you use tyres that are approved by Audi you can be sure that the
actual tyre dimensions will be correct for your vehicle. If you decide
to fit a different type of tyre, you must obtain the appropriate manu-
facturer's certificate from the tyre retailer to confirm that the tyres
are suitable for your vehicle. Keep this certificate in a safe place.
Your local Audi dealer will be able to advise you on which tyres may
be fitted to your vehicle.
On vehicles with four-wheel drive, all four tyres must always be
fitted with tyres of the same type, make and tread pattern, as other-
wise the driveline can be damaged by continuous variations in the
wheel speeds. For the same reason, only use a spare wheel* with
the same tyre dimensions as the normal road wheels.
It the spare tyre* is not the same type as the tyres fitted on the car
(for example if the car has winter tyres or wide-section tyres) you
should only use the spare tyre if a puncture occurs, and then only
for a short period of time. In this case, please drive with extra care.
Refit the normal road wheel as soon as possible.
It is best to have all servicing of wheels and tyres performed by a
qualified workshop. They have the necessary special tools and
3)COC = certificate of conformity
225
Tyre width in mm
50
Height/width ratio in %
R
Tyre construction: Radial
17
Rim diameter in inches
94
Load rating code
Y
Speed rating code letter
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Technical data In winter road conditions winter tyres will considerably improve the
car's handling. Due to their type of construction (width, rubber
compound, tread pattern), summer tyres give less grip on ice and
snow. This applies particularly to vehicles equipped with wide
section tyres or high speed tyres (code letters H, V or Y on the side-
wall).
Only use winter tyres of the correct type approved for your vehicle.
The sizes of the winter tyres approved for your vehicle are listed in
the vehicle's documents (e.g. EC Certificate of Conformity or COC
document
4)). The vehicle documents vary depending on the
country of residence. Also refer to ⇒page 270, ⇒page 270.
Winter tyres are no longer fully effective when the tread is worn
down to a depth of 4 mm.
The performance of winter tyres is also severely impaired by ageing,
even if the tread is still much deeper than 4 mm.
Winter tyres are subject to the following maximum speed limits
according to speed rating code letter: ⇒
In Germany vehicles capable of exceeding these speeds must have
an appropriate sticker attached so it is visible to the driver. Suitable
stickers are available from Audi dealers and specialist retailers.
Please note regulations to this effect in your country.“All-weather” tyres can also be used instead of winter tyres.
Using winter tyres with V-rating
Please note that the generally applicable 240 km/h speed rating for
winter tyres with the letter "V" is subject to technical restrictions;
the maximum permissible speed for your vehicle may be signifi-
cantly lower. The maximum speed limit for tyres with a V-rating
depends directly on the maximum axle weights for your car and on
the listed weight rating of the tyres being used.
It is best to contact an Audi dealer to check the maximum speed
which is permissible for the V-rated tyres fitted on your car on the
basis of this information.
WARNING
Exceeding the maximum speed permitted for the winter tyres
fitted on your car can cause tyre failure, resulting in a loss of
control of the vehicle – risk of accident.
For the sake of the environment
Summer tyres should be fitted again as soon as possible; they give
better handling on roads which are free of snow and ice. Summer
tyres produce less rolling noise, do not wear down as quickly and,
most importantly, reduce fuel consumption.Snow chains
Snow chains will improve the vehicle's handling on snow-
covered roads.– Snow chains can be used on the front wheels only.
– Keep your speed below 50 km/h.Snow chains will improve braking ability as well as traction in winter
conditions.
4)COC = certificate of conformitySpeed rating code letter
⇒page 270, ⇒page 270
Maximum speed limit
Q
160 km/h
S
180 km/h
T
190 km/h
H
210 km/h
V
240 km/h
(note restrictions)
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Technical data Furthermore, this could cause damage to your vehicle and
possibly also result in an accident.
Note
•
If you cannot continue driving even with run flat tyres please
obtain professional assistance.
•
You should obtain professional assistance if you are in any doubt
regarding the rims and tyres for your vehicle.
Applies to vehicles: with run flat tyresDriving with run flat tyres
Please remember that the vehicle's handling will be
impaired.Driving a vehicle with a deflated tyre, or with insufficient
tyre pressure, is an abnormal situation. However, since the
handling of a vehicle equipped with run flat tyres is only
slightly impaired, it is important to remember that you are
driving with a deflated tyre. If you have to make use of the
run flat system please remember the following points:
– The Electronic Stabilisation Program (ESP) must be
switched on.
–Do not exceed 80km/h ⇒.
– Anticipate the traffic situation well in advance.
– Be careful when accelerating.
– Avoid unnecessary braking and steering manoeuvres.
– Reduce speed in good time before corners and potential
hazards.
Please refer to ⇒page 274, “ When is it no longer possible to
continue driving with the help of the run flat tyres?”
Effects on handling when driving with defective tyres
If one of the front tyres is defective, your vehicle will tend to pull
slightly towards that side and braking performance will be
impaired.
A defective rear tyre will also make the vehicle pull slightly to one
side, and the braking response will again be slightly impaired.
These effects will be most noticeable when driving in a corner.
WARNING
•
When using the run flat system the changes in vehicle handling
will be noticeable when braking, in corners and during fast accel-
eration.
•
The maximum permitted speed of 80 km/h is subject to road
and weather conditions. Always observe the relevant rules and
regulations. Run flat tyres allow you to continue your journey in
the event of a loss of tyre pressure. However, the driver remains
responsible for the safety of the vehicle and for restoring the
correct tyre pressure and having defective parts replaced
⇒page 276. For these reasons you should always adjust your
driving to suit the circumstances.Caution
We recommend that you drive with great care when making use of
the run flat system. Avoid abrupt manoeuvres.
WARNING (continued)
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