2012 AUDI A8 engine

Engine cooling system
Coolant
The engine coolant performs two functions: it
keeps the engine from overheating and it pro ­
te cts the engine from freezing in the winter .
The cooling system is sealed and generally re­
qu ires little attention .
The cooling system has been filled at the fac­
tory with a permanent coolant which does not need to be changed. The coolant consists of a
mixture of water and the manufacturer's gly ­
col-based coolant additive G13 ant ifreeze
w ith anticorrosion add itives (SO% fo r USA
models; 60% for Canad ian models). This mix­
ture bot h assu res the ne cessary frost protec­
tion and protects metal components in the
engine's coo ling system from corrosion and
scaling. It also raises the boili ng po int of t he
coolant.
D o not red uce the concentration o f the coo l­
ant in the summer by adding plain water .
The
proportion of coolant addit ive must be at
least 50% but not mo re than 60 %
to main­
tain antifree ze protection and cooling efficien­
cy. If the coolant frost protection is too low,
the coolant cou ld freeze and damage the veh i­
cle heating and eng ine cooling system .
For year-round driving, antifree ze is added at
the factory for temperatures down to:
- -3 1°F (-3S°C)USA
- -40 ° F ( - 4 0 °C) Canada.
A WARNING
Before yo u check anything in the engine
compartment , always read and heed a ll
WARNINGS ¢
& in Working in the engine
compartment on page 219.
(D Note
- Befo re winter sets i n, have the coolant
chec ked to see i f th e coo lant ad dit ive i n
you r vehicle is suffic ient to meet the cli­
mate cond itions . T hi s is especially impor­
ta nt if yo u live in a regi on whe re the w in-
-
Checkin g and fillin g 22 7
ter is ex treme ly co ld. If necessary, i n­
crease t he p ro po rtion of coo lant additive
to 60%.
- W hen a dding coolant additive to yo ur
cooling system , remembe r:
- We recommend us ing on ly coo la nt ad­
di tive G 12++ or G 13 for your v ehicle .
T his co olan t ad ditive is av ailab le at au­
t hor ized A udi dealers . O ther types of
an tifree ze can signi fican tly reduce cor ­
r osion pro te ction . The resulti ng cor ro ­
sion can ca use a loss of coolant a nd se­
rious engine damage.
- Do not add any ty pe of rad iator leak seal ­
ant to you r vehicle's engine coo lant .
Add ing radiator repair flu id may adverse ­
ly affect t he fu nction and performance of
your cooling system and cou ld result in
damage not covered by yo ur New Ve hicle
L imited Warranty .
Checking the engine coolant level
The engine coolant level can be checked with
a quick glance.
Fig. 179 En gine co mpart ment: cover on t he coo la nt
expansio n ta nk
Before you check a nyth ing in the eng ine com­
partment,
always read and heed all WARN­
INGS <=>&.
in Working in the engine compart ­
ment on page 219 .
Park your vehicle on a level surface.
.., Switch off t he ignition.
.., Read t he engine coolant level from the
coo lant expansion tank¢
fig. 179,
¢ page 221 . With a cold engine, the coolant
level shou ld be between the "min" and
"ma x" markings . When the engi ne is warm, ..,.

228 Checking and filling
the level may be slightly above the "max"
marking.
The location of the coolant expansion tank
can be seen in the engine compartment illus­
tration
¢ page 221.
To obtain an accurate reading, the engine
must be switched off.
The expansion tank in your vehicle is equipped
with an electric coolant level sensor.
When the coolant level is too low, the warning light in the Auto-Check System¢
page 15 will
illuminate until you add coolant and the level
has been restored to normal. Even though
there is an electric coolant level sensor , we
still recommend you check the coolant level
from time to time.
Coolant loss
Coolant loss may indicate a leak in the cooling
system. In the event of coolant loss, the cool­
ing system should be inspected immediately
by your authorized Audi dealer.
It is not
enough merely to add coolant.
In a
sealed system, losses can occur only if
the boiling point of the coolant is exceeded as
a result of overheating.
_& WARNING
The cooling system is under pressure and
can get very hot. Reduce the risk of scald­
ing from hot coolant by following these
steps. -
- Turn off the engine and allow it to cool
down.
- Protect your face, hands and arms from
escaping fluid and steam by covering the
cap with a large, thick rag.
- Turn the cap slowly and very carefully in
a counter-clockwise direction while ap­
plying light, downward pressure on the
top of the cap .
- To avoid being burned, do not spill anti­ freeze or coolant on the exhaust system
or hot engine parts. Under certain condi­
tions, the ethylene glycol in engine cool­
ant can catch fire .
(D Note
Do not add any type of radiator leak seal­
ant to your vehicle's engine coolant. Add­
ing radiator repair fluid may adversely af­
fect the function and performance of your
cooling system and could result in damage not covered by your New Vehicle Limited
Warranty .
Adding coolant
Be very careful when adding engine coolant.
Before you check anything in the engine com­
partment,
always read and heed all WARN­
INGS ¢&. in Working in the engine compart ­
ment on page 219.
.. Turn off the engine .
.. Let the engine cool down.
.. Place a thick rag over the coolant expansion
tank
¢ page 227, fig . 179 and carefully
twist the cap counter-clockwise ¢,&. .
.,. Add coolant.
.. Twist the cap on again
tightly.
Replacement engine coolant must conform to
exact specifications
¢ page 22 7, Coolant. We
recommend using only coolant additive G12+
+, G3 or in an emergency G12+ . Do
not use a
different additive. In an emergency use plain
water until you can get the correct additive
and can restore the correct ratio. This should
be done 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 fill coolant above the
"MAX" mark . Ex­
cess coolant will be forced out through the
pressure relief valve in the cap when the en­
gine becomes hot.
_& WARNING
-= -- The cooling system is under pressure and
can get very hot. Reduce the risk of ..,_

scalding from hot coo lant by following
these steps.
- Turn
off the engi ne and a llow it to cool
down.
- Protect your face, hands and arms from
escapi ng fl uid and steam by cover ing
the cap with a large, thick rag .
- Turn the cap slowly and very ca refully
i n a cou nte r-clockw ise dir ect ion while
a pply ing lig ht, downwa rd p ress ure on
the top of the cap.
- T o avo id being burned, do no t sp ill an­
tifree ze o r coolan t on t he exh aust sys­
tem or ho t engine parts . Un der certain
conditions, the ethylene glyco l in en­
gine coolant can catch fire .
- Antifree ze is poisono us. Always store an­
tifreeze in its or iginal co ntainer and we ll
o ut o f the reac h of children.
- If you drain the coolant , it must be
caught and safely stored in a p roper con ­
tainer clear ly marked "poison".
(D Note
- Coolant po llutes the env ironment and
could ca use a n engine fire . Excess coo l­
ant wi ll be forced out through the pres ­
sure re lief va lve in the cap when the en­
gine becomes hot.
- If, in an emergency, only water can be
added , the correct ratio between water
and antifreeze¢
page 22 7 must be re­
stored as soon as possib le .
@ For the sake of the environment
Drained coolant should not be re used . Al­
ways dispose of used c oolant while observ­
ing all envir onmental regulations .
Radiator fan
The radiator fan switches on automa tically by
itself
T he radiator fan is driven by the engine via the
V-be lt. The viscous clutch regulates the speed
of the fan according to the temperature of the
coolant .
Checkin g and fillin g 229
An auxiliary electric radiato r fan* sw itches on
and
off depending on coolant temperature
and othe r vehicle ope rat ing con ditions.
After yo u switc h the engi ne off, the aux iliary
f an can con tinue r unning for up to 10 minutes
- even with the ignition off. It can even switch
on again later by itself¢ & , if
- t he temperatu re of the engine coo lant rises
due to the heat b uild -up from the en gine in
the engi ne compartment, or
- the engine compartment heats up be cause
the vehicle is parked in intense sunlight.
A WARNING
- To reduce the risk of personal in jury nev­
er touch the radiator fan.
- The a uxiliary electric fan is temperat ure
contro lled and can switch on sud denly
even when the engine is not running.
- The a uxiliary radiator fa n switches on a u­
tomatically when the engine coo lant
reaches a certain temperature and will
continue to run until the coo lant temper­
ature drops .
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a
qui ck glance.
Fig. 180 En gin e compar tment: cov er o n th e bra ke fluid
r ese rvoir
Befo re you check anyth ing in the eng ine com­
partment ,
always re ad and heed all WARN­
INGS c::> ,& in Working in the engine compar t-
ment on page 219 . .,..

230 Check ing and filling
• Read the brake fluid level from the brake
fluid reservoi r¢
fig. 180, ¢ page 221. The
brake f lu id leve l must be between the "MIN"
and "MAX" markings.
The location of the brake fluid reservoir can be
seen in the engine compartment illustration
co page 221.
The fl uid level may drop slightly after some
time due to the automatic adjustment of the brake pads . This is not cause for alarm .
I f the brake fluid level falls
considerably be­
l ow the "MIN" mark, the brake wa rning/indi ­
cator light- (U.S.
models) ;II (Canadian
models) will come on ¢
page 14. Do not con­
tinue to operate the vehicle. The comp lete
brake system should be thoroughly checked
by an authorized Audi dealer or other quali­
fied fac ility and the cause corrected. If the
brake fluid level is too low, the brake war ning/
in dicato r light w ill illuminate . Contact an au­
thor ized A udi dealer
immediately .
Changing brake fluid
Have the brake fluid changed by an experi­
enced technician .
Brake fluid absorbs moistu re from the a ir . If
the water content in the brake fluid is too
h igh, corrosion in the brake system may result
after a per iod of t ime . The bo iling po int of the
b rake fluid w ill also decrease considerably and
dec rease braking per formance.
Therefore, the brake flu id must be changed
e ver y two yea rs. A lways use new b rake fluid
which confo rms to Fede ral Motor Vehicle
Standard "FMVSS 1 16 DO T 4".
The brake flu id rese rvoi r ca n be difficult to
r ea ch, therefo re , we re commend that yo u
have the brake fl uid changed by yo ur a utho r­
ized
Audi dealer. Your dea ler has the correct
too ls, the right brake fluid and the know-how
to do this for you .
A WARNING
-Brake flu id is poisonous. It must be stor­
ed only in the closed or iginal conta iner
out of the reach of children!
- Brake failure can resu lt from o ld or inap­
prop riate brake flu id . Obse rve these pre ­
cautions:
- Use only brake fluid that meets SA E
specification
J 1703 and conforms to
Federa l Moto r Ve hicle Standard 1 16 .
A lways check with your authorized A udi
dealer to make sure you are using the
correct brake fluid . The cor rect type of
brake flu id is also ind icated on the
brake flu id rese rvoir .
- The brake fluid must be new . Heavy use
of the brakes can cause a vapo r lock if
the b ra ke fluid is left i n the system too
l o ng. This can se riously affect the effi ­
c iency of the br akes as well as your
sa fety. This co uld resu lt in an accident.
(D Note
Brake fluid will damage the pai nt of you r
vehicle.
@ For the sake of the environment
Because of the p rob lem of proper disposal
of b ra ke fluid as well as the spec ial too ls
r equired and the nece ssary expe rti se, we
r ecommend that yo u have the brake fl uid
changed by yo ur authorized Aud i dea ler.
Battery
General information
U nder normal operat ing cond itions, the bat­
te ry in yo ur Audi does not need any ma inte­
nance . With
high outside temperatures or
l o ng da ily d rives we recommend that you have
the e lec trolyte leve l checked by a serv ice fa­
c ility. The electrolyte leve l should also be
checked each time the battery is cha rged
¢ page 233. .,..

Have the battery checked when you take your
vehicle in for service. Yo u are well advised to
replace a battery that is older than 5 years .
W ith certa in types o f airbag deployment, the
battery is disconnec ted from the vehicle elec ­
trica l system for safety reasons
c::> &. in Re­
pair, care and disposal of the airbags on
page 156.
Disconn ecting the battery terminal s
Some vehicle functions (power w indow regu­
l ators, for example) are lost if the battery ter­
minals are disconnected . These functions have
to be re learned after the battery terminals are
connec ted again. To prevent this, the battery
should only be disconnected from the vehicle
e lectrical system when absolutely necessary
for repairs .
Vehicles not driven for long period s
If you do not drive your vehicle over a period
of several days or weeks, electrical compo­
nents are gradually cu t back or switched off .
This reduces energy consumption and main ­
tains starting capability over a longer per iod
c::> page 192. Some of the convenience func­
tions may not operate, s uch as the inte rior
lights o r the power sea t adjustment . T he con­
ve nience fun ct ions wi ll be available again
when yo u switch on the ignition and start the
engine.
Winter operation
During the winter mont hs, ba ttery capaci ty
t ends to decrease as tempe rat ures d rop . Th is
is because more powe r is also consumed while
starting , and the headlights, rear window de ­
fogger, etc., are used more oft en.
Avoid unnecessary power cons umption, par­
ticularly in c ity t ra ff ic or when t raveling on ly
short distances. Let your a uthorized Audi
dealer check the capac ity of the vehicle bat ­
tery before winter sets inc::>
page 233. A well
charged battery w ill not only prevent starting
problems whe n the weather is cold, but will
also last longer .
Checkin g and fillin g 231
(D Tips
If your vehicle is left standing for seve ral
weeks at extremely low temperatures, the
vehicle battery shou ld be removed and
stored where it w ill not freeze. This will
prevent it from be ing damaged and having
to be replaced .
Working on the battery
Be especially careful when working on or near
the battery.
The battery is located in the l uggage compart­
ment under the floor. Before you check any­
th ing in the luggage compartment,
read and
h eed all WARNINGS
c::> &_ .
Always heed the safety warnings , when work­
ing on the vehicle battery or the vehicle e lec­
trical system to prevent injury.
The following WARNINGS are very
important when working on the battery:
Al ways heed the follo wing WARNING SYM­
BOLS and safety precautions when working on the battery.
@
®
Always wear eye protection.
Battery acid contains sulfuric acid.
Always w ear glove s and eye prot ec­
tion .
No
- sparks
-flames
- smoking .
When a battery i s charged, it produ­
ce s hydrogen gas wh ich i s ex plosive
and could cause per sonal injury .
Always keep the battery well out of ]
reach of children .
_& WARNING ~
Whenever working on the battery o r on
the electrical system, there is the risk of injury, accident and even fire . Read and
heed the following WARNINGS:
•
•

232 Checking and filling
-Always wear eye protection. Do not let
battery acid or any lead particles get on
your skin or clothing . Shield your eyes .
Explosive gases can cause blindness or
other injury .
- Battery acid contains sulfuric acid . Sulfu­
ric acid can cause blindness and severe
burns .
- Always wear gloves and eye protection.
Do not tilt the battery because acid
could leak out of the ventilation open­
ings.
- If you get battery acid in your eyes or
on your skin, immediately rinse with
cold water for several minutes and get
medical attention .
- If you should ingest any battery acid,
seek medical attention immediately.
- Do not expose the battery to an open
flame, electric sparks or an open light.
- Do not smoke.
- Do not interchange the positive and neg-
ative cables.
= When working on the battery , be sure
not to short-circuit the terminals with
tools or other metal objects. This would cause the battery to heat up very quickly,
which could lead to damage or explosion
and personal injury.
- When a battery is charged, it produces hydrogen gas which is explosive and
could cause personal injury .
- Always keep the battery well out of the
reach of children .
- Before work is done on the electrical sys­ tem, disconnect the negative ground ca­ble.
- Before performing any work on the elec­
trical system, switch
off the engine and
ignition as well as any electrical equip ­
ment . The negative cable on the battery
must be disconnected . If you are just go­
ing to replace a light bulb, then it is
enough to switch
off the lights.
- Before disconnecting the battery, switch
off the anti-theft alarm system! Other­
wise you will set off the alarm. -
When disconnecting the battery, first
disconnect the negative cable and then
the positive cable.
- Before reconnecting the battery, make
sure all electrical consumers are switch­
ed off. Reconnect the positive cable first
and then the negative cable . Never inter ­
change the cables - this could start a fire!
- Never charge a frozen or a thawed-out
battery .
It could explode! If a battery has
frozen, then it must be replaced . A dis­
charged battery can freeze over at 32 °F
(0 °C) .
-Make sure the vent hose is always attach­
ed to the opening on the side of the bat­
tery .
- Never use batteries which are damaged.
There is the danger of an explosion! Al­
ways replace a damaged battery.
A WARNING
California Proposition 6S Warning:
- Battery posts, terminals and related ac­
cessories contain lead and lead com­
pounds, chemicals known to the State of
California to cause cancer and reproduc­
tive problems. Wash hands after han­
dling.
(D Note
- Do not disconnect the vehicle battery
when the ignition is on or when the en­ gine is running, otherwise, you will dam­
age electronic components in the electri­
cal system.
- If your vehicle is going to stand for a
long period of time without being driven,
protect the battery from "freezing", oth­
erwise it will be damaged and will then
have to be replaced .

Battery charging
Starting the engine requires a well charged battery .
Fig. 181 Eng ine co mpa rtmen t: connectors for a charg ­
er a nd jump sta rt cab les
A lwa ys re ad and heed all WARNING S below
c:> &. and c:> &. in Working on the battery on
page 231 .
.. Switch off the ignit ion and all electrical con­
sumers .
.. Make sure the area is well ventilated when
you charge the battery .
.. Open the engine hood
c:> page 219 .
.. Remove the cover (D by p ress ing on the ar­
row
c:> fig . 181.
.. Open the cove r@ on the positive term inal.
.. Connect the charger connectors according
to the instructions to the
jump start bolt s.
(Bolts under the red cover= "positive", Bolts
with hex head = "negative").
.. Only now plug the mains lead for the charg­
ing equipment into the wall outlet and turn
it on
c:> 8_ .
.. Ma ke sur e t he ch arging rat e is no t over
30 amp s/14 .8 Volt .
.. When the batte ry is f ully charged: Turn the
charging equ ipment off a nd remove the
mains lead from the wall outlet.
.. Now remove the clamps for the charging
equipment.
.. Close the red cover on the positive pole .
.. Close the hood
c:> page 220 .
A discharged battery can freeze at tempera­
tures of on ly 32
F0 (0 °C) . A llow a fro zen bat­
tery to thaw completely before attempt ing to
charge it
c:> .&. . However, we recommend not
using a thawed battery again because the bat -
Checking and fillin g 233
tery casing can be cracked due to ice forma ­
tion and can leak battery acid.
Battery charging (Maximum charging rate
of 30 amps /14.8 Volt )
When charging at low voltages (e.g. with a
trickle cha rger ), the battery cables do not
have to be disconnected f irst . The battery
caps should
not be opened when charging a
battery.
It is not necessary to remove the battery from
the luggage compartment, and it is a lso not
necessary to disconnect the cab les.
Fast ch arging the batte ry (charging rat e
a bove 14.8 V olt s)
For technica l reasons do not use a battery
charger that uses voltage greater than 14.8
Volts to charge your vehicle's battery .
A WARNING
-
Charging a battery can be dangerous .
- Always follow the operating instructions
provided by the battery charger manu­
facturer when charg ing your battery .
- Never charge a frozen battery. It may ex­
plode because of gas trapped in the ice .
Allow a frozen battery to thaw out first.
- Do not reuse batteries wh ic h were fro­
zen. The battery housing may have
cracked and weakened when the battery
froze.
- Cha rge the battery in a well ventilated
area . Keep away from open flame or elec­
trical spar k. Do not smo ke. Hyd rogen gas
generated by the battery is explos ive .
- To reduce the danger of explosion, never
connect or d isconnect charger cab les
while the charger is ope rat ing .
- Fast cha rging a batte ry is dange rous and
should only be at tempted by a compe­
tent techn ic ian wi th the prope r equip­
ment .
- Ba ttery acid that may spi ll dur ing charg­
ing should be washed off with a solution
of warm water and baking soda to neu ­
tralize the ac id.

234 Check ing and filling
Never use a fast charger as a booster to
start the engine. This will seriously dam­
age sensitive electronic components, such
as control units, relays, rad io, etc ., as well
as the battery charger.
Battery replacement
The new bat tery must have the same specifi­
cations and dimensions as the original equip­
ment battery .
Intelligent energy man agement in your veh i­
cle is respons ible for d istributing the electr i­
cal energy throughout your vehicle
c::> page 192. The intell igent energy manage­
ment system w ill keep the engine battery
cha rged bette r than vehicles w ithout t his sys­
tem. To make sure the additional e lectrica l en­
e rgy is availab le once again after you have
changed the battery, we recommend that you install batteries of the same type and manu ­
facture only (the same as those installed at
the time your vehicle was delivered). Specifi­
cations are listed on the battery hous ing. Your
author ized dealer must code the battery in
the energy management system to enable you
to use the energy management funct ions cor­
rectly after replac ing the battery .
The new battery must have the same capacity ,
voltage (12 volts), amperage, construct ion
and plug sealing.
When installing the ba ttery, make sure the ig­
n ition and all e lectr ica l consumers are sw itch ­
ed off .
{[) Note
Make sure the venti lation hose on the s ide
of the battery is connected, otherwise
fumes or battery ac id can leak out .
@ For the sake of the environment
Because of the problem of proper d isposa l
of a battery, we recommend your author ­
ized Aud i dealer change the battery for
you . Batter ies contain su lfuric ac id and l
ead and must a lways be disposed o f prop­
erly in compliance with a ll environmental
regulations. Disposing of vehicle batter ies
i mproperly is very dangerous to the envi­
ronment .
Windshield/headlight
washer container
Fig . 1 82 Eng in e compar tmen t: cov er on the w inds hield
washe r flu id rese rvoir
T he washer fluid co nta iner is marked w ith the
symbol~ on its cap
c::> fig. 182, c::>page 221.
.. Before you check anything in the engine
compartment, always read and heed all
WARNINGS c::> _& in Working in the engine
compartment on page 219.
.,. Lift the fil le r cap tongue to add washer flu­
id. You can fi ll the container to the top.
.. Press the cap back onto the fi ller neck after
fi lling the container .
You can find the reservo ir
ca pacit y in the table
in
c::> pag e 278 .
Clean water should be used when filling up. If
poss ible, use soft water to prevent scaling on
washe r jets . Always add a g lass cle aner solu­
tion (with frost protection in the winter).
(D Note
Do not mix engine coolant a ntifreeze or
any other addi tives to fill up the wind­
shield washer reservoir .