2008 AUDI S6 coolant

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& WARNING
• Never turn off the engine until the vehicle has come to a
complete stop.
• The brake booster and servotronic only work when the engine
is running. With the ignition turned off, you have to apply more
force when steering or braking. Since you cannot steer and stop
normally, this can lead to accidents and serious injuries.
• For safety reasons, you should always park your vehicle with
the selector lever in P. Otherwise, the vehicle could inadvertently roll away.
• After the engine has been switched off, the radiator fan can
continue to run for up to 10 minutes -even with the ignition
switched off. It can also switch on again after some time if the
coolant temperature rises as the result of a heat buildup or if the
engine is hot and the engine compartment is additionally heated
by the sun's rays.
0 Note
If the engine has been under heavy load for an extended period,
heat builds up in the engine compartment after the engine is
switched off -there is a risk of damaging the engine. Allow the
engine to run at idle for about 2 minutes before switching it off. •
Applies to vehicles: w ith Advanced Key
Driver messages in the instrument cluster
display
If a function is not present, a driver message appears.
No key identified
This message appears when the [STAR T) button is pressed if there
is no master key inside the vehicle or if the system does not recog­
nize it. For example, the master key cannot be recognized if it is
covered by an object (e.g. aluminum brief case) which
screens the radio signal.
.Electronic devices such as cell phones can also inter­
fere with the radio signal.
Press brake pedal to start engine
This message appears if you press the [ START) button to start the
engine and do not depress the brake pedal. The engine can only be
started if the brake pedal is depressed.
Engage N or P to start engine
This message appears when the engine is started if the selector
lever for the automatic transmission is not in the P or N position.
The engine can only be started with the selector in these positions.
? Key not in vehicle
This message appears along with the symbol if the master key is
removed from the vehicle with the engine running. It is intended to
remind you (e.g. when changing drivers) not to continue the journey
without the master key.
If the master key is no longer in the vehicle, you cannot switch off
the ignition after stopping the engine and you also cannot start the engine again. Moreover, you cannot lock the vehicle from the
outside with the key.
Shift to P, otherwise vehicle can roll away. Doors do not lock if lever
is not in
P.
This message appears for safety reasons along with a warning
buzzer if the selector lever for the automatic transmission is not in
the P position when the ignition is switched off with the
[STOP)
button and the driver's door is opened. Move the selector lever to
the P position, otherwise the vehicle is not secured against rolling
away. You also cannot lock the vehicle using the locking button on
the door handle or using the remote key.
To engage steering lock, press and hold STOP button
This message appears for safety reasons if the engine and the igni ­
tion have been switched off by pressing the [
STOP) button once, .,,_

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Speed
The higher the speed, the more difficult it becomes for the driver to
control the rig. Do not drive at the maximum permissible speed. Reduce your speed even more if load, weather or wind conditions
are unfavorable -particularly when going downhi ll.
Reduce vehicle speed
im med ia tel y if the trailer shows the slightest
sign of swaying.
Do not try to s top the swayi ng by accelerating.
Observe speed limits. In some areas, speeds for vehicles towing
trai lers are lower than for regular vehicles .
Always apply brakes ear ly. When driving downhill, shift into a lower
gear to use the engine braking effect to slow the vehicle. Use of the
brakes a lone can cause them to overheat and fail.
C ool ant t emp era tur e
The coolant temperature gauge=> page 13 must be observed care­
fully. If the needle moves close to the upper end of the scale, reduce
speed immed iately and/or turn off the air conditioner.
If the coolant temperature warning light in the instrument cluster
starts flashing
- F- , pull off the road, stop and let the engine idle for
about two minutes to prevent heat build-up.
& WARNING
A nyo ne n ot properly re str aine d in a moving vehi cle i s at a mu ch
g re ater ri sk in an accident . Never let any on e r ide in y our car who
is n ot pr operl y wea ring th e re stra ints pr ovided b y Audi . •
Trailer towing tips
Important to know
Your vehicle handles differently when towing a trailer because of
the additional weight and different weight distribution. Safety, performance and economy will greatly depend on how carefully you
l
oad your trailer and operate your r ig.
Before you actually tow your trailer, practice turning, stopping and
backing up in an area away from traffic . Keep practicing unti l you
have become comp letely familiar with the way your vehicle-trai ler
combination behaves and responds.
Back ing up is difficult and requires practice. Backing up with a
trailer generally requires steering action opposite to that when backing up your vehic le without a tra iler.
Ma intain a greater distance between your veh ic le and the one in
front of you . You will need more room to stop. To compensate for
the trai ler, you w ill need a larger than norma l turning radius.
When passing, remember that you cannot accelerate as fast as you nor mally wou ld because of the added load . Make su re you have
enough room to pass. After passing, allow plenty of room for your
trai ler befo re changing lanes again .
Avoid jerky starts, sharp turns or rapid lane changes.
[ i ] T ips
• Do not tow a trailer during the break -in period of your vehicle.
• I f you tow a trailer, your Audi may require more frequent main te­
nance due to the extra load=>
page 366. •
Parking on a slope
Do not park on a slope with a trailer. If it cann ot be
avoi ded, do so only after d oing the followi ng:
When p arking :
-Apply the foot brake.
- Have someone p lace chocks under both the vehicle and
the trailer wheels. ._

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Checking and filling
Engine hood
Releasing the engine hood
The engine hood is released from inside the vehicle.
-Open the driver's door .
Fig. 229 Driver's side
footwell: engine hood
release lever
-Pull the release lever on the left under the instrument
panel
=> fig. 229 in the direct ion of the arrow.
The hood pops up slightly under spring pressure. •
Opening the engine hood
Fig. 230 Release lever
under the engine hood
Before opening the engine hood, make sure that the wind­
shield wipers are flat against the windshield. Otherwise,
they could damage the paint on the hood.
Lift the hood slightly =>&, .
Pull up on the release under the hood => fig. 230. This
releases the catch.
- Open the hood all the way.
The hood is kept in the open position by two gas struts.
& WARNING
Hot engine coolant can burn you.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood. •

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•
Closing the engine hood
- Pull the hood down until the pressure from the struts is
reduced .
- Let the hood
drop down and latch in place. Do not try to
push it shut;
it may fail to engage => &.
& WARNING
A hood that is not completely latched could fly up and block your
view while driving.
• When you close the engine hood, check it to make sure the
safety catch has properly engaged. The hood should be flush with
the surrounding vehicle body parts.
• If you notice while driving that the hood is not secured prop­
erly, stop at once and close it. •
Working in the engine compartment
Be especially careful whenever you work in the engine
compartment.
Whenever you must perform any work in the engine compartment,
for example checking and filling different fluids, there is a risk of injury, burns and accidents. To prevent personal injury always
observe the following WARNINGS. The engine compartment of any
vehicle is a hazardous area
~ & .
& WARNING
To help avoid injury, before you check anything under the hood :
• Turn off the engine.
• Remove the ignition key.
• Apply the parking brake .
& WARNING (continued)
• Move selector lever to "P" (Park).
• Always let the engine cool down. Hot components will burn
skin on contact.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood.
• Keep children away from the engine compartment .
• Never spill fluids on hot engine components. They can cause a
fire.
• Never touch the radiator fan. The auxiliary electric fan is
temperature controlled and can switch on suddenly.
• Never open the coolant reservoir cap when the engine is still
warm . The coolant system is pressurized and hot coolant could
spray out.
• Protect your face, hands and arm from steam or hot engine
coolant by placing a thick rag over the cap when you open the
coolant reservoir.
• If work on the fuel system or the electrical system is necessary :
- Always disconnect the battery.
- Never smoke or work near heaters or open flames . Fluids in
the engine compartment could start a fire.
- Keep an approved fire extinguisher immediately available.
• To avoid electrical shock and personal injury while the engine
is running or being started, never touch:
- Ignition cables
- Other components of the high voltage electronic ignition system.
• If you must perform a check or repair with the engine running: -First, fully apply the parking brake, move selector lever to "P"
(Park). .,
Vehicle care
I t •

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•
because the lubricating properties of oil diminish gradually during
normal vehicle use .
Under some circumstances the engine oil should be changed more
frequently . Change oil more often if you drive mostly short
distances, operate the vehicle in dusty areas or under predomi ­
nantly stop -and -go traffic conditions, or have your vehicle where
temperatures remain below freez ing for extended periods.
Detergent additives in the oi l will make fresh oil look dark after the
engine has been running for a short time. This is normal and is not
a reason to change the oi l more often than recommended .
Because of the problem of proper disposal, along with the specia l
tools and necessary expertise required, we strongly recommend
that you have your oi l changed by an authori zed
Audi dea ler or a
qual ified service stat ion.
If you choo se to cha nge yo ur oi l y ou rse lf, please no te the following
important information:
& WARNING
To reduce the risk of per sonal injury if you m ust change the engine
o il in you r veh ic le y our self :
• Wear eye protection.
• To reduce the ri sk of burn s from hot engine oil , let the engine
c ool down to the tou ch.
• When removing the oil drain plug with your fing ers , sta y as far
away as po ssi ble . Alw ay s k eep your f orearm par allel to the gr ound
to help pre vent hot oil from running down your arm .
• Drain t he oil int o a contain er de signed for thi s purpo se , one
large enough to hold at l ea st th e total amount of oil in your eng ine .
• Engine oil i s poi sono us. K eep it well out of the rea ch of ch ildr en .
• Continuou s contact with u sed engine oil i s harmful to your
sk in. Al wa ys prote ct you r ski n by washing oil off thoroughl y with
s oap and w ater.
0 Note
Never mix oil addi tives with your engine oil. These add itives can
damage your engine and adversely affect your Audi Limited New
Vehicle Warranty .
c£> For the sake of the environment
• Before changing your oi l, first make sure you know where you
can properly dispose of the us ed oil.
• Always dispose of used engine oil properly. Do not dump it on
garden soil , wooded areas, into open streams or down sewage
drains .
• Recycle used engine oil by taking it to a used engine oil collec ­
tion fac ility in your area , or contact a service station. •
Engine cooling system
Coolant
The engine coolant performs two functions: it keeps the
engine from overheating and it protects the engine from
freezing i n the winter.
The cooling system is sea led and generally requires little attention.
The coo ling system has been fi lled at the factory with a permanent
coolant which does not need to be changed . The coolant consists of
a mixture of water and the manufac turer's glycol-basedcoolant
additive G 12+ an tifreeze with anticorrosion additives (50% for USA
models; 60% for Canadian models). This mixture both assures the
necessary frost protection and protects metal components in the
engine 's cooling system from corrosion and scaling . It also raises
the boiling point of the coolant.
Do not reduce the concentration of the coo lant in the summer by
adding plain water.
The p ropo rt ion of co ola nt additiv e mu st be at .,_
Vehicle care
I t •

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le as t 50% b ut not mor e th an 60 % to maintain antifreeze protection
and cooling efficiency . If the coo lant frost protection is too low, the
coo lant could freeze and damage the vehicle heating and engine
cooling system.
For year -round driving, antifreeze is added at the factory for temper­
atures down to:
• -31 °F ( -35 °C) USA
• -40 °F ( -40 °C) Canada.
You can m ix the
Gl 2 + coolant additive with other add itives (for
example
Gl 1 or Gl 2). A lways check with your authorized Audi
dea ler .
& WARNING
Before you check anyt hing in the engine comp artment , alw ays
re ad and heed all WARNINGS ~
& in "Working in the eng ine
co mpar tm ent " o n
pag e 297.
0 Note
• Before win ter sets in, have the coolant checked to see if the
coolant additive in your vehicle is sufficient to meet the climate
conditions. This is especia lly important if you live in a region where
the winter is extremely cold. I f necessary, increase the proportion of
coo lant additive to 60%.
• When adding coolant additive to your coo ling system,
remember:
-We recommend using only coolant additive
Gl 2+ (check the
label) for your vehicle. This coolant addit ive is available at autho ­
rized Audi dealers. Other types of antifreeze can significantly
reduce corrosion protect ion . T he resulting corrosion can cause a
loss of coolant and serious engine damage.
• Do not add any type of radiator leak sealant to your vehicle's
engine coolant. Adding radiator repair fluid may adversely affect the function and performance of your cooling system and cou
ld result
in damage not c overed by your New Vehicle Limited Warranty. •
Checking the engine coolant level
The engine coolant level can be checked with a quick
glance.
F ig . 235 Eng ine
c o mpartm ent : Cool ant
ex pa nsion tank
Before you check anything in the engine compartment,
always read and heed all WARNINGS~
& in "Working in
the e ngin e compa rtment" on
page 297 .
Turn off the ignition.
Re ad the en gine coo lant leve l from the coo lant exp an­
sio n ta n k~ fig. 235. With a cold eng ine, the coolan t leve l
sho uld be between the "m in" and "max" markings. W hen
t h e eng ine is warm, the level may be s lightly abov e the
"max" marking .
The location of the coolant expansion tank can be seen in the
engine compartment illustration~
page 298.
To obtain an accurate reading, the engine must be switched off .
T he expansion tank in your vehicle is equipped with an e lectric
coo lant leve l sensor.

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•
When the coolant level is too low , the warning light in the Auto­
Check System =>
page 33will blink un til you add coo lant and the
level has been restored to normal. Even though there is an electric
coolant leve l sensor, we still recommend you check the coo lant level
from time to time .
Coola nt lo ss
Coolant loss may indicate a leak in the cooling system . In the event
of coolant loss, the coo ling sys tem should be inspected immedi ­
ately by your authorized Audi dealer . It is not enough merely to add
coolant.
In a
s ealed system, losses can occur only if the boiling po int of the
coolant is exceeded as a result of overheating.
0 Note
Do not add any type of radiator leak sea lant to your vehicle's engine
coolant . Adding radiator repair fluid may adversely affect the func ­
tion and performance of your cooling system and could resu lt in
damage not covered by your New Vehic le Limited War ranty .•
Adding coolant
Be very careful when adding engine coolant.
Before you check anything in the engine compartment,
always read and heed all WARNINGS => & in "Working in
the engine compartment" on
page 297 .
- Tu rn off the engine .
- L et the engine coo l dow n.
- Place a t hick rag over the coolant expansion tank
=> page 304, fig . 235 and carefully tw ist t he cap counter­
cloc kw ise
=> & .
- Add coolant. - Twist the cap
on agai n
tightly.
Replacement engine coolant must conform to exact specifications
=>
page 303, "Coolant". If in an emergency coolant additive G12 + is
not avai lable, do
not use a different additive . Use p lain water
instead until you can get the correct additive and can restore the
correct ratio . This should be do ne as soon as possible.
If you have lost a considerable amount of coolant, then you should
add cold antifreeze and cold water only when the engine is cold .
Always use
new engine coolant when refilling .
Do not fil l coolant above the "MAX" mark. Excess coolant will be
forced out through the pressure relief va lve in the cap when the
engine becomes ho t.
& WARNING
• The cooling system is under pressure and can get ver y hot.
Redu ce the risk of sc alding from hot coolan t by follow ing the se
s tep s.
- Turn off th e en gine and allo w it to cool down .
- Protect your fa ce , ha nd s and arm s from e sc a pi ng fluid and
s tea m by cov ering the c ap with a large , thick rag.
- Tur n the cap slo wly an d very ca refully in a counter -clockw is e
dire ction whil e applying light , downward pres sure on the top
o f the cap.
- To av oid bei ng burn ed , do n ot spill antifree ze or cool ant on
the e xhau st sy stem or h ot e ngi ne part s. Under cert ain co ndi­
tion s, the ethylen e gl ycol in engin e co olant c an c atch fire .
• Antifr eeze is po iso nous. Alwa ys store antifree ze in its or igin al
c ontainer and well out of the reach of c hildren .
• If you dra in t he coola nt, it mu st b e ca ught and sa fel y stor ed in
a prop er container clearly mark ed "poi son ".
~
Vehicle care I t •

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0 Not e
• Coolant pollutes the environment and cou ld cause an engine
fire. Excess coolant will be forced out through the pressure relief
valve in the cap when the engine becomes hot.
• If, in an emergency, only water can be added, the correct ratio
between water and antifreeze ~
page 303 must be restored as soon
as possible .
ci> For the sake of the environment
Dra ined coolant should not be reused . Always dispose of used
coolant whi le observing all environmental regulations. •
Radiator fan
The radiator fan switches on automatically by itself.
The rad iator fan is driven by the eng ine v ia the V-be lt . The v iscous
clutch regulates the speed of the fan according to the tempera ture
of the coo lant .
An auxiliary electric radiator fan * swi tches on and off depending on
coo lant temperature and other vehicle operating conditions.
After you switch the engine off, the auxiliary fan can continue running for up to 10 minut es -even with th e igni tion o ff. It can even
switch o n again later by itself~ & , if
• the temperature of the engine coo lant rises due to the heat
bui ld -up from the engine in the engine compartment, o r
• the engine compartment heats up because the vehic le is parked
in intense sun light.
& WARNING
• To reduce the ri sk of per sonal injury never tou ch the radiator
f a n.
& W AR N ING (continu ed )
• The auxiliary e le ctri c fan i s temperature controlled and can
s w itch on suddenly even when the engine is not running .
• The auxiliary radiator fan swit ches on automatically when the
engine coolant reache s a ce rtain temperature and will con tinue to
run until the coolant t emperatur e drop s. •
Brake fluid
Checking brake fluid level
Th e brake fluid level c an be checked with a quick glance.
Fig . 23 6 En gin e
co mp art m ent : B ra ke
fl uid re servoir
Befo re yo u c heck anything in th e en gin e compar tme nt,
always read and heed all WARNINGS~ & in "Working in
the eng ine compartment" on
page 297 .
Rea d the brake fl uid level from the bra ke fluid reservoir
~ fig . 236. T he b rake fluid leve l must be betwee n the
" M IN " and "MAX" markings.
The brake fluid reservoir is located at the rear parti tion of the engine
compartment on the left side~
page 298. .,_