2015 AUDI A8 engine

238 Check ing and filling
• Let the engine coo l down .
• Place a thick rag over the coolant expansion
tank
¢ page 237, fig . 204 and care full y
twist the cap counter-clockwise¢ _&..
• Add coolant mixed in the correct ratio
¢
page 236, Coolant up to the MAX mark­
i ng.
• Make sure that the fluid level rema ins sta-
ble. Add more coolant if necessary.
• Twist the cap on again
tightly.
Replacement engine coolant must conform to
exact specifications ¢
page 236, Coolant.
We recommend using only coolant additive
G12++, G13 or in an emergency G12+ . Do not
use a different additive . In an emergency use
p la in water unt il you can get the correct add i­
tive 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 co ld antifreeze
and cold water only when the engine is co ld.
Always use
new eng ine coolant when refilling .
Do not fi ll coolant above the "MAX" mark. Ex­
cess coolant will be forced out through the pressure relief valve in the cap when the en­
g ine becomes hot .
A WARNING
- T he coo ling system is under p ressure and
can get very hot. Reduce the risk of
scalding from ho t coolant by following
these steps.
-Turn off the eng ine and a llow it to cool
down.
- Protect your face, hands and arms from escaping flu id and steam by cover ing
the cap with a large, thick rag.
- T urn the cap slowly and very carefully
in a counter-clockwise d irect ion while
apply ing light, downward pressure on
the top of the cap.
- To avo id being burned, do not sp ill an­
tifreeze or coolant on the exhaust sys­
tem or hot engine parts . Under certa in cond
it ions, the ethylene g lycol in en­
gine coolant can catch fire.
- Antifreeze is poisonous . A lways store an­
tifreeze in its origina l container and well
out of the reach of children.
- If you dra in the coo lant, it must be
caught and safely stored in a proper con­
tainer clearly marked "po ison".
@ Note
- Do not add coolant if the expansion tank
is empty. Air co uld enter the cooling sys­
tem and damage the engine. If this is
the case, do not cont inue driving. Seek
professional assistance .
- Coo lant pollutes the environment and
cou ld cause an engine f ire. Excess cool­
ant will be forced out through the pres­
sure relief valve in the cap when the en­
gine becomes hot.
- If, in an eme rgency, only wate r can be
added, the co rrect ratio between water
and antifreeze ¢
page 236 must be re­
stored as soon as possible.
@ For the sake of the environment
D rained coolant should not be reused . Al­
ways d ispose of used coolant while observ­
i ng all envi ro nmental regula tions.
Radiator fan
The radiator fan switches on automatically by
itself
The rad iator fan is driven by the e ngine via the
V-belt. The viscous clutch regulates the speed of the fan acco rding to the temperatu re of the
coolant.
An auxiliary electric radiato r fan* sw itches on
and off depending on coolant temperature
and ot her vehicle ope rat ing condit io ns.
After you switch the eng ine off, the aux iliary
fan can continue running for up to 10 m inutes
- even w ith the ignition off .
It can even switch
o n aga in later by itself¢.& , if
1111>

- the temperature of the engine coolant rises
due to th e heat bui ld-up from the engine in
the engine compartment, or
- the engine compartment heats up because
the vehicle is parked in intense sunlight.
.&_ WARNING
- To reduce the r isk of personal injury nev­
er touch the radiator fan.
- The auxiliary electr ic fan is temperature
controlled and can switch on sudden ly
even when the engine is not runn ing.
- The auxiliary radiator fan switches on au­ tomat ically when the engine coolant
reaches a certain temperature and will
continue to run until the coolant temper ­
at ure drops.
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a
quick glance.
N N
-N
i
F ig . 2 05 Eng ine co mpartmen t: cove r on the b rake f lui d
r eservo ir
Before you check anything in th e engine com­
partment,
alwa ys read and he ed all WARN­
INGS c::> .&. in Working in the engine compart­
ment on page 2 28.
~ Read the brake fluid level from the brake
fl uid reservo ir ~
fig . 205, c::> page 230. The
brake f luid leve l must be betwee n the "M IN"
and "M AX" marki ngs.
The location of the brake fl uid reservo ir can be
see n in t he engi ne comp artment illus trati on
c::> page 230.
Checkin g and fillin g 239
The fluid level may d rop slightly afte r some
time due to the automatic adjustment of the
brake pads . T his is not cause for alarm .
If the brake flu id leve l falls considerably be­
low the "MIN" mark, the brake warning/indi­
cator light . (U.S. models) . (Canadian
models) w ill come on
~ page 14 . Do not con­
tin ue to operate the vehicle . The complete
brake sys tem should be thoroughly checked
by an authorized Audi dea ler or other quali ­
fied facility and the cause corrected.
If the
brake f lu id leve l is too low, the brake warning/
indica tor ligh t will illumi nate. Conta ct an au­
thorized Aud i de aler
immediately .
Changing brake fluid
Have the brake fluid changed by an experi­
en ced technician.
B rake fluid absorbs moisture from the air . If
the water content in the brake fluid is too
high, co rrosion in the brake system may resu lt
after a pe riod of time. The boiling point of the
brake f lu id will also dec rease conside rably and
decrease brak ing performance.
T herefo re , the bra ke fluid must be changed
every tw o year s. Always use new br ake f lu id
which con forms to Federal Mo tor Veh icle
Standard " FMVSS 116 DOT 4".
T he bra ke fluid reservo ir can be d iff icu lt to
reach, the refore, we recommend that you
have the bra ke fluid changed by your author­
ized
Audi dealer. Your dealer has the cor rect
tools, 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 container
out of the reach of children!
- Brake failure can resu lt from old or inap­
prop riate brake f lu id. Observe these pre­
cautions:
- U se only brake fluid tha t meets SAE
specificat ion
J 1703 and conforms to
Federa l Motor Vehicle Standard 116.

24 0 Ch eck ing and filling
Always check wi th your a uthorized Audi
dealer to make s ure you are using the
correct brake flu id. The correct type of
brake fluid is also indicated on the
brake fluid reservoir.
- The brake fluid must be new. Heavy use
of the brakes can cause a vapor lock if
the brake fluid is left in the system too
long. This can ser ious ly affect the effi­
ciency of the b ra kes as well as yo ur
safety. This could result in an acc ident.
(D Note
Brake flu id will damage the paint of your
veh icle.
@ For the sake of the environment
Because of the problem of proper d isposa l
of brake flu id as wel l as the special tools
requ ired and the necessary expert ise, we
recommend that you have the b rake fluid
changed by your author ized Audi dealer.
Battery
General information
Under
normal operating conditions, the bat­
tery in your Audi does not need any mainte­
n ance . With
high outside temperatures or
l ong daily dr ives we recommend that you have
the elec trolyte level checked by a service fa­
cili ty. The e lec trolyte level sho uld a lso be
checked each time the battery is charged
¢ page 242.
Have the b attery checked when you ta ke yo ur
ve hicl e in for service. Yo u are well adv ise d to
replace a battery that is older than S years .
W ith certa in types of airbag deployment, the
battery is d isconnected from the vehicle ele c­
tr ica l system for sa fety reasons¢
& in Re­
pair, care and disposal of the airbags on
page 165.
Disconnecting the battery terminals
Some veh icle func tions (power w indow regu­
l ato rs, for example) a re los t if the b attery ter- mina
ls are disconnected. These functions have
to be relearned after the battery termina ls are
connected aga in. To prevent th is, the battery
sho uld only be disconnected from the ve hicle
electrical system when abso lutely necessary
for repairs.
Vehicle s not driven for long peri ods
If you do not d rive your vehicle over a period
of several days or weeks, e lectr ica l compo ­
nents are gradually cut back or sw itched off.
This reduces energy consumption and ma in­
ta ins start ing capability over a longer period
¢
page 202. Some of the convenience func­
t ions may not ope rate, such as the inter ior
li gh ts or the power seat adjus tment. The con­
venience func tions will be ava ilable ag ain
when you switch on the ignition and start the
engine .
Winter operation D uring the winte r months, battery capac ity
tends to de crease as temperatures drop. This
is beca use more power is also consumed wh ile
sta rting, and the headlights, rear window de ­
fogger, etc ., are used more often .
Avoid unnecessary power consumpt ion, p ar­
t icu lar ly in city traffic or whe n traveling only
short distances. Let yo ur au thorized Aud i
dealer check the capacity of the vehicle bat ­
tery before winter sets in ¢
page 242. A well
charged battery will not on ly prevent starting
problems when the weather is cold, but will
also last longer.
(!) Tips
If your vehicle is left standing for several
weeks at extremely low temperatures, the
vehicle battery sho uld be removed and
stored where it w ill not freeze. This will
prevent it from be ing damaged and having
to be repla ced.

24 2 Ch ecking and filling
-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 dange r of an explosion! Al­
ways replace a damaged battery .
A WARNING
California Proposition 65 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.
- Do not d isconnect the veh icle battery
when the ignition is on or when the en­
gine is running, otherwise, you will dam­
age electronic components in the electri­
ca l system.
- If your veh icle is go ing to stand for a
l ong period of time without being driven,
protect the battery from "freezing", oth­
erwise it w ill be damaged and w ill then
have to be replaced.
Battery charging
Starting the engine requires a well charged
battery.
Fig. 2 06 Engine compartme nt: connecto rs fo r a cha rg ­
e r and jump star t cab les
Alwa ys re ad and h eed all WARNINGS below
¢
A and ¢ A in Working on the battery on
page
241.
.. Switch off the ignition and all electrical con­
sumers .
.. Make sure the area is we ll ventilated when
you charge t he battery.
.. Open the eng ine hood ¢
page 228.
.. Remove the cover (D by pressing on the ar­
row ¢
fig. 206 .
.. Open the cover @on the pos it ive terminal.
.. Connect the charger connectors according to
the inst ructions to the
jump start b olt s.
(Bolts under the red cover = "posit ive", Bo lts
w ith hex head= "negative") .
.. On ly now plug the mains lead for the charg ­
ing equipment into the wal l o utlet and turn
iton ¢
,&.
.. M ake sure the cha rging rate is not over
3 0 amps /14.8 Volt .
.. When the battery is fully charged: Turn the
charg ing equipment off and remove the
mains lead from the wall out let .
.. Now remove the clamps for the charging
equ ipment.
.. Close the red cover on the positive pole .
.. Close the hood ¢
page 229.
A discharged battery can freeze at tempera ­
tu res of only 32 F
0 (0 °C). Allow a frozen bat­
te ry to thaw completely before attempting to
charge it¢ & . However, we recommend not
us ing a thawed battery again because the bat­
tery casing can be cracked due to ice forma ­
t ion and can leak battery acid.
Battery cha rging (M ax imum charging rate
of 30 amp s/14.8 Volt )
When charg ing at low vo ltages (e.g. with a
t rickle cha rge r), the battery cables do not
have to be disconnected first. The battery
caps should
not be opened when charg ing a
battery.
It is not necessary to remove the battery from
the luggage compartment, and it is also not
necessary to d isconnect the cab les .

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'SI: .... \!) 1.1"1
.... 1.1"1 ,....,
Fa st charging the b att ery (charging rate
abo ve 14.8 Vo lt s)
Fo r technical reasons do not use a batt ery
charger that uses vo ltage g reater 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 charging your battery.
- Never charge a fro zen battery. It may ex­
plode because of gas trapped in the ice.
Allow a frozen battery to thaw out first .
- Do not reuse batteries which were fro­
zen. The battery housing may have
cracked and weakened when the battery
froze .
- Charge the battery in a well ventilated
area . Keep away from open flame or elec­
trical spark . Do not smoke . Hydrogen gas
gene rated by the battery is exp losive.
- To reduce the danger of explosion , never
co nnect or disconnect cha rger cables
wh ile the charger is operating.
- Fast charg ing a battery is dangerous and
should only be attempted by a compe­
t ent technicia n w ith the proper eq uip­
ment.
- Battery a cid that may spill d uring charg­
ing should be washed off wit h a solution
of warm wa ter and ba king soda to neu ­
tralize the acid .
CD Note
Never use a fast charge r as a booster to
s tart the engine. This will se rio usly d am­
age sensitive elect ronic components, such
as control units, relays, radio, etc., as we ll
as the battery charger .
Checking and fillin g
Battery replacement
The new battery must have the same specifi­
cations and dimensions as the original equip­
ment battery.
In telligen t energy managemen t in your vehi­
cle is responsible for distributing the electri ­
cal ene rgy throughout your vehicle
¢ page 202. The intelligent energy manage­
ment system will keep the engine battery
c h arged better than vehicles without this sys ­
tem. To make sure the additional electrica l en ­
ergy is avai lab le once again afte r yo u have
changed the battery, we recommend that you
insta ll batteries of the same type and m anu­
facture only (the same as those installed at
the time your ve hicle was delivered) . Specif i­
cat ions are listed on the battery housing . Your
authorized dea le r must code the battery in
the energy management system to enab le you
to use the ene rgy manageme nt func tions cor ­
re ct ly afte r replacing the battery.
The new battery must have the same capacity,
vo ltage
( 1 2 volts), amperage, const ruction
and plug seal ing .
When installing the battery, make sure the ig­ nition and a ll elect rical consume rs are switch­
ed off .
CD Note
- Make sure the ventilation hose on the
side of the battery is connected, other­
w ise fumes or battery a cid ca n leak out .
- Veh icles with the Start-Stop-System* are
e quipped with a spec ial cycle-p roof AGM
battery. Install ing a d iffe rent type of
ba ttery c an cause problems in the vehi ­
cle e lectrical system. Whe n replacing the
vehicle battery, always install one w ith
the same specifications as the origina l
battery.
- Battery mounts and clamps must a lways
be sec ured correct ly .
- Read and fo llow the wa rnings under
¢ page 241, Working on the battery be-
fore per forming any work on the battery . ..,_
243
•
•

244 Checking and filling
@ For the sake of the environment
Because of the problem of proper disposa l
of a battery, we recommend your author­
ized Audi dealer change the battery for
you. Batter ies contain sulfuric acid and
lead and must always be disposed of prop­
erly in compliance w ith all environmental
regu lations . D isposing of vehicle batteries
improperly is very dangerous to the envi­ ronmen t.
Windshield/headlight
washer container
Fig. 207 Engine compartment: cover on the windshield
was her flui d reservo ir
The washer fluid container is marked with the
symbol~ on its cap
c::> fig. 207, c::> page 230 .
.. Before you check anyth ing in the engine
compartment,
always read and heed all
WARNINGS c::> A in Working in the engine
compartment on page 228 .
.. lift the filler cap tongue to add washer flu­
id . You can fill the container to the top .
.. Press the cap back onto the filler neck after
filling the container.
You can find the reservoir
capacity in the table
in
c::>page 288.
Clean water should be used when filling up. If
possible, use soft water to prevent scaling on
washer jets. Always add a glass cleaner solu­
tion (with frost protection in the winter).
(D Note
Do not mix engine coolant antifreeze or
any other additives to fill up the wind­
shield washer reservoir.

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' "' ....
"' ....
Vehicle tool kit
Vehicle tool kit and jack
The vehicle tool kit is located in the luggage
compartment under the cargo floor cover.
Fi g. 217 Luggage compartment: cargo floor cover
folded upward
Fig. 218 Trunk lid: Vehicle too l ki t
.. Lift the cargo floor by the plastic handle.
.. Hook the handle into the luggage compart­
ment weather strip ¢
fig. 217.
.. Remove the spare wheel to reach the vehicle
tool kit .
.. Remove the foam p iece.
The onboard tool kit includes:
- Hooks to remove the wheel
covers* or wheel
hub covers
- Plastic hook to
remove wheel bolt covers*
- Wheel bolt wrench
- Al ignment p in for changing wheels
- Screwdriver with reversible blade
- Towing loop
- Jack
Before storing the jack, make sure it is wound
back down as far as it will go.
What do I d o now ? 267
A WARNING
Im proper use of the vehicle jack can cause
serious personal injur ies.
- Never use the screw driver hex head to
tighten wheel bolts, since the bolts can­
not attain the necessary tighten ing tor­
que if you use the hex head, potentially
causing an accident.
- The factory-supplied jack is intended on­
ly for yo ur vehicle model. Under no c ir­
cumstances should it be used to lift heavy veh icles or other loads; you risk in­
ju ring yo urself.
- Never start the engine when the vehicle
is raised, wh ich could cause an acc ident.
- Support the vehicle securely with appro­
priate stands if work is to be performed
underneath the vehicle; otherwise, there
is a potentia l risk for injury.
- Never use the jack supplied wit h your
Audi on another vehicle, particularly on a
heavier one. The jack is only s uitable for
use on the vehicle it came with.
(D Tips
-Some of the onboard items listed above
are provided on certain models only or
are optional ext ras .
- Before yo u can raise your vehicle using
the jack, you must activate the jacking
mode
¢page 272 .

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"' ....
Spare wheel
Applies to vehicles: with spare wheel
The spare wheel is stored in the wheel well
underneath the floor panel in the luggage
compartment.
F ig. 220 Luggag e co mpartm ent : spar e wh eel
Taking out the sp are whee l
• Lift the cargo floor by the plast ic handle
c:::>fig . 220.
• Hook the hand le into the luggage compart­
ment weather strip .
• Turn the large screw
c:::> fig. 220 counter­
clockwise.
• Takeout the spare tire.
• Always store the vehicle tool kit , the jack*
and the replaced tire in the luggage com­
partment
c:::> page 139 .
• Unhook the ca rgo floor before closing the
rear lid.
& WARNING
-
Loose items in the passenger compart­
ment can cause serious pe rsonal in jury
during hard braking or in an accident.
- Never store the spare wheel or jack and
tools in the passenger compartment.
@ Tips
Check the inflat ion p ressu re of the spare
tire periodically to keep the tire ready for
use.
What do I d o now ? 269
Changing a wheel
Before changing a wheel
Observe the following precautions for your
own and your passenger's safety when chang ­
ing a wheel.
• After you experience a t ire failure, pull the
car well away from moving traffic and try to
reach
leve l ground before you stop c:::> ,&.
• All passengers should le av e t he ca r and
move to a safe location (for ins tance, behind
t he guardra il)
c:::> ,& .
• Engage the parki ng br ake to prevent your
vehicle from rolling unintentionally
c:::> ,& .
• Move sele ctor lever to po sit ion P c:::> ,&. .
• If you are towing a trailer, unhitch the trailer
from your ve hicle.
• Take the
jac k and the sp are tire out of the
luggage compartment
c:::> page 267,
c:::> page 268 .
& WARNING
You o r you r passengers could be i njured
while changing a wheel if you do not fo l­
low these safety precaut ions:
-I f you have a flat tire, move a safe d is­
tance off the road. Turn off the engine,
turn the eme rgency flashers on and use
other warning devices to a lert other mo­
torists .
- Make sure that passengers wait in a safe
place away from the vehicle and well
away from the road and traffic.
- To help prevent the vehicle from moving
suddenly and possibly slipping off the
jack, always f ully set the parking brake
and b lock the wheel d iagonally opposite
the wheel be ing changed. When one
front wheel is lifted off the ground, plac­ ing the Automatic Transmission in "P"
(Par k) will
not prevent the vehicle from
mov ing .
- Before you change a wheel, be sure the
ground is level and firm. If necessary,
use a sturdy board under the jac k.
-