engine AUDI A8 2018 Repair Manual

u. co .... N
" N .... 0 0 :c ' @ For the sake of the environment
-Oil should never enter the sewer system or
come into contact with the ground.
- Pay attention to legal requirements when
disposing of empty oi l containers .
Changing the engine oil
We recommend that hove your oil changed by on
authorized Audi dealer or a qualified service sta­
tion .
Before you check anyt hing in the engine compart ­
ment,
alw ays re ad and h eed all W ARNINGS ¢ &
in Working in the engine comportment on
page 272.
The engine oil must be changed according to the
intervals specified in your Warranty
& Mainte­
nance booklet . This is very important because the
lubricating properties of oil diminish gradually
during normal vehicle use.
Under some circumstances the engine oi l should
be changed more frequently. Change oil more of­
ten if you drive mostly short distances, operate
the vehicle in dusty areas or under predominantly
stop-and-go traffic condit ions, or have your vehi­
cle where temperatures remain below freezing
for extended periods .
Detergent additives in the oil will make fresh oil
look dark after the engine has been running for a
short t ime . Th is is normal and is not a reason to
change the oil more often than recommended .
Because of the problem of proper disposal, along
with the special tools and necessary expertise re­
qu ired, we strongly recommend that you have
your oil changed by an authorized
A ud i d ea ler or
a qualified se rvice station .
If you choo se to chang e your o il y ou rse lf, please
note the following important information:
A WARNING
T o reduce the r isk of personal injury if you
must change the engine oil in your ve hicle
yourse lf:
- Wear eye protection .
-
Check ing and F illing
- To reduce the risk of burns from hot engine
oil, let the engine cool down to the touch.
- When removing the oil drain p lug with your
fingers, stay as far away as possible. Always keep your forearm parallel to the ground to
help prevent hot oil from running down your
arm.
- Drain the oil into a container designed for
this purpose, one large enough to hold at least the total amount of oil in your engine.
- Engine oil is poisonous. Keep it well out of
the reach of children .
- Continuous contact with used engine o il is
harmful to your skin. Always protect your
skin by wash ing oil off thoroughly with soap
and wate r.
@ Note
Never mix oil additives with your engine oil.
These add itives can damage your engine and
adversely affect your Audi L imited New Vehi­
cle War ranty .
@ For the sake of the environment
-Before chang ing your o il, first make sure
you know where you can properly d ispose of
the used oil.
- Always dispose of used engine o il properly .
Do not dump it on garden so il, wooded
areas, i nto open streams o r down sewage
dra ins.
- Recycle used eng ine o il by tak ing it to a used
eng ine oi l collection fac ility in yo ur area, or
c ontact a se rvice station.
Cooling system
Coolant
The eng ine cooling system is filled w ith a mixture
of purified water and coolant additive at the fac­
tory. This coolant must not be not changed .
The coo lant level is mon itored through
the . in­
dicator
light¢ page 20. However, we do recom­
mend occasionally checking the coolant level
manually .
.,.
277

Checking and Filling
If you must add coolant, use a mixture of water
and coolant additive . Mixing the coolant additive
with distilled water is recommended.
Coolant additive
The coolant additive is made of anti-freezing and
corros ion protection agents. Only use the follow ­
ing coo lant additives .
Coolant additive Specification
Gl2evo
TL 774 L
Gl2++ TL 774 G
Gl3
TL 774 J
These additives may be mixed wi th each othe r.
The amount of coo lant additive that needs to be
mixed with water depends on the climate where
the vehicle will be operated. If the coolant addi ­
tive percentage is too low, the coo lant can free ze
and damage the engine.
Coolant addi- Freeze protec-
tive tion
Warm regions min.
40%, min. -13 °F
max . 45% (-25 °()
C old regions min.
50%, max. -40 °F
max.
55% (-40 °C)
@ Note
-Before the start of winter, have an author­
ized Audi dealer or authorized Audi Service
Faci lity check if the coolant additive in your
vehicle matches the percentage appropriate
for the climate. This is especially important
when driving in colder climates .
-If the appropriate coolant additive is not
available in an emergency, do not add any
other addit ive for risk of damaging the en­
g ine . If this happens, only use water and re­
store the correct mixture ratio with the
specified coolant additive as soon as possi­ ble.
-Only refill with new coolant.
-Radiator sealant must not be mixed w ith
the coolant.
278
Adding coolant
Fig. 260 Eng in e compar tment : coolant exp ansion tank
cover
Observe the safety precautions ~.&, in Working
in the engine compartment on page 2
72.
Checking the engine coolant level
~ Park the vehicle on a level surface .
~ Switch the ignit io n off.
~ Read the coolant level on the coolant expansion
tank ~ page 2 74. The coolant leve l must be be­
tween the MIN and MAX markings when the en­
gine in co ld. When the engine is warm it can be
slightly above the MAX marking,
Adding coolant
Requirement: there must be a residual amount of
coolant in the expansion
tank ~(©) .
~ Let the engine cool down .
~ Place a cloth over the coolant expansion tank
cap and unscrew the cap counterclockwise
~.&. -
~ Add coo lant mixed in the correct ratio
~ page 277 up to the MAX marking.
~ Make sure that the f luid level remains stable.
Add more coolant if necessary .
~ Close the cap securely .
Coo lant loss usually indicates there is a leak . Im ­
mediate ly drive your vehicle to an authorized
Audi dealer or authorized Audi Service Fac ility
and have the cooling system inspected. If the
cooling system is not leaking, a loss can come
from the coolant bo iling t hrough overheat ing
and being pushed out of the cooling system .

lL
_& WARNING
-The cooling system is under pressure. Do
not open the coolant expansion tank cap
when the engine is hot. This increases the
risk of burns .
- The coolant additive and the coolant can be dangerous to your health. For this reason,
keep the coolant in the original container
and away from children. There is a risk of
poisoning.
- When working in the engine compartment,
remember that the radiator fan can switch
on even if the ignition is switched off, which
increases the risk of injury.
CD Note
Do not add coolant if the expansion tank is
empty. Air could enter the cooling system and
damage the engine. If this is the case, do not
continue driving. See an authorized Audi deal­
er or authorized Audi Service Facility for assis­
tance.
Brake fluid
N N
-N
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Fig. 261 Engine compartment: cap on brake flu id reservoir
Observe the safety precautions ~&. in Working
in the engine compartment on page 2
72.
Checking the brake fluid level
.. Read the brake fluid level on the brake fluid
reservoir
~ page 274, fig. 258. The brake fluid
level must be between the MIN and MAX mark­
ings~&. -
~ The brake fluid level is monitored automatically .
...... N ...... 0 0 :c ' Checking and Filling
Changing the brake fluid
Have the brake fluid changed regularly by an au­
thorized Audi dealer or authorized Audi Service
Facility.
_& WARNING
-
- If the brake fluid level is below the MIN
marking, it can impair the braking effect
and driving safety, which increase the risk of
an accident . Do not continue driving . See an
authorized Audi dealer or authorized Audi
Service Facility for assistance.
- If the brake fluid is old, bubbles may form
in the brake system during heavy braking.
This would impair braking performance and
driving safety, which increases the risk of an
accident.
- To ensure the brake system functions cor­
rectly, only use brake fluids that comply
with VW standard 50114 or FMVSS-116 DOT 4.
CD Note
- If the brake fluid level is above the MAX
marking, brake fluid may leak out over the
edge of the reservoir and result in damage
to the vehicle.
- Do not get any brake fluid on the vehicle
paint, because it will corrode the paint.
Battery
General warnings about batteries
Because of the complex power supply, all work
on batteries such as disconnecting, replacing,
etc., should
only be performed by an authorized
Audi dealer or authorized Audi Service Facility
~ .&. .
The term "vehicle battery" refers to the 12 Volt
battery in your vehicle.
Detailed warnings for the vehicle battery:
® Wear eye protection.
b. Bat~ery acid is highly corrosive. Wear pro-
~ tect1ve gloves and eye protection. Ill>-
279

Checking and Filling
@
Fire, sparks, open flame and smok ing are
forb idden.
~
A highly explosive mixture of gases can
form when charging batteries.
®
Keep c hildren away from battery acid and
batteries.
A WARNING
All work on the battery or electrical system in
your vehicle can result in injuries, chemical
burns, accidents or burns. Because of this, a ll
work must be performed
only by an author­
ized Aud i dea le r o r authorized Aud i Serv ice
Facility.
A WARNING
California Proposit ion 65 Warning:
- Battery posts, terminals and re lated acces­
sories contain lead and lead compounds,
chemicals known to the Sta te of California
to ca use ca nce r and rep roduct ive p roblems.
Wash hands after handling.
{Q) Note
If the v ehicle wi ll be par ked for long periods
of t ime, pro tect i t against the co ld so that it
w ill not be destroyed by "freezing"
¢page 280.
Vehicle battery
The term "vehicle battery" refers to the 12 Volt
bat tery in your vehicle.
Not running the vehicle for long periods of
time
I f you do not dr ive your vehicle for seve ral days or
weeks, elec trical equipmen t is gradually scaled
back or switched off. This reduces energy use and
ensu res the vehicle wi ll be able to start after long
periods of
time ¢ page 131. Some convenience
functions, such as interior lighting or power seat
ad justment, may not be available under certa in
circumstances. These convenience funct ions w ill
be ava ilable aga in once you switch the ignition on
and start the engine.
280
Even when electrical equipment is swi tched o ff,
the equipment can still drain the vehicle battery i f the ve hicle is not dr iven fo r long periods of
time. Deep draining results in a chemica l reaction
that destroys the ins ide of the vehicle battery.
The vehicle battery must be charged every month
to reduce the risk of this
happen ing ¢ page 280.
Contact an autho rized Aud i dea le r or a uthorized
A udi Se rvice Fa cility for mo re information.
Winter operation
Co ld weather places higher demands on the vehi­
cle battery. T his res ults in reduced starting abili ­
ty . Have the vehicle ba tte ry checked by an au­
thorized Aud i dea ler or author ized Audi Service
Fa cil ity befo re the cold time of ye ar.
Charging the vehicle battery
Fi g. 262 Eng ine compa rtment: connectors fo r a cha rger
and jump start cab les
Requirement: only use chargers with a ma ximum
charging voltage of 30 amp s/14.8 Volts.
The
vehicle battery cab les remain connected .
.. Read the warnings ¢.&. in General warnings
about batteries on page 280
and ¢ _&. .
.. Switch off the ignitio n and all electrica l equip­
ment.
.. Open the hood ¢ page 2 73 .
.. Remove the cover (I) by pressing on the arrow
¢fig. 262.
.. Open the cover @on the pos it ive terminal.
.. Clamp the charger terminal clamps to the jump
star t pins accord ing to the inst ru ct ions. (pin un­
de r the cover= "positive", p in wit h hex agon al
head = "nega tive") .
.. Insert the power cable for t he cha rging dev ice
into the socket and switch the device on.
Ill>

u. co .... N
" N .... 0 0 :c ' ~ At the end of the charging process, switch the
charger off and pull the power cab le out of the
socket.
~ Now remove the charg ing device terminal
clamps .
~ Close the cover @on the positive term inal and
re-install the
cover (!).
~ Close the hood c:;, page 2 73 .
A drained battery can freeze at temperatures
around
322F (0QC) . A frozen or thawed out bat­
tery must no longer be used . The battery hous ing
could be cracked by the format ion of ice , which
could cause battery acid to leak out
c:;, ,&. .
Charg ing the b attery
Only use chargers with a ma ximum charg ing
v oltage of 14 .8 V.
The battery connecting cables
do not need to be disconnected . Do not open the
battery when charg ing .
Read all of the manufacturer's instructions for
the charger before charging the battery .
A WARNING
-A h ighly exp losive mixture of gases can form
w hen cha rging batter ies. O nly charge t he
vehicle ba tte ry in well -vent ilated a reas.
- A d rained vehicle battery can freeze at tem­
peratu res a round 32
Q F (0 QC). A froze n or
thawed ve hicle battery m ust not be ch arged
and must not be used anymore. The battery
housing can crack and battery acid can leak
out if ice forms, whic h increases the risk of
an exp losion and chemical burns. Contact an
authorized Audi dealer or authorized Aud i
Service Facility for more information.
- Do not connect or disconnect the charg ing
cable while charg ing because th is increases
the risk of an explosion .
(D Tips
-Only charge the vehicle battery through the
connections in the engine compartment.
-Read all of the manufacturer's instructions
for the charger before charg ing the ve hicle
battery .
Ch eck ing and F illing
Windshield washer
system
F ig . 263 E ngin e compar tmen t: was he r fl ui d reservo ir cap
M N
-N ' "' "' m
The windshield washer fluid reservoir O contains
the cleaning solution for the windshie ld and the
headlight washer system
c:;, fig. 263, c:;, page 274.
The reservoir capacity can be found in
<=> page 334.
To reduce the risk of lime scale depos its on the
spray nozzles, use clean water with low amounts
of calcium. Always add w indow cleaner to the wa­
ter . When the outside temperatures are cold, an
anti -freezing agent should be added to the water
so that it does not freeze .
@ Note
-The concentration of ant i-freez ing agent
must be adjusted to the veh icle operat ing
condit ions in the respective cl imate . A con­
centration that is too high can lead to vehi­
cle damage.
- Never add radiato r anti-freeze or other addi­
t ives to the washer fluid.
- Do not use a glass cleaner that conta ins
paint so lvents, because t his could damage
the paint.
Service interval display
The service interval display detects when your ve­
hicle is due for service.
T he serv ice interval d isplay wo rks in two stages:
-In sp ec tio n o r oil change remind er: after a cer-
tain distance driven , a message appears in the
.,.
2 8 1

Checking and Filling
instrument cluster display each time the ign i­
tion is switched on or off . The rema ining
distance or time is displayed br iefly.
- Inspection or oil change due: if yo ur vehicle
h as reached an inspection o r oi l change interval
o r both intervals at t he same time, the mes­
sage
Inspection due! or Oil change due! or Oil
change and inspection due!
appears br iefly af­
te r switch ing the igni tion on/off .
Checking service intervals
You can check t he rema ining distance o r time un­
til the next oil change o r next inspec tion i n the
Ca r menu. To do this, select: the
IC ARI function
button
> Car systems contro l bu tton > Service &
control > Service intervals .
Resetting the indicator
A n author ized A udi dealer or authorized A udi
Serv ice Facility will reset the serv ice interval d is­
p lay after pe rforming serv ice .
I f yo u have chan ged t he oil you rself, you must re ­
set t he oil change interva l.
To reset the in dic ator, se le ct : th e
ICAR I fu nc tion
but ton
> Car system s control button > Service &
control > Service intervals. T urn t he control knob
downwa rd to
Reset oil change interval an d press
the co ntro l knob.
{QJ Note
- On ly reset the oil ch ange in dicato r if the oil
was c han ge d.
- Fo llow ing the service i nte rvals is cr itical to
maintai ning the service life a nd value o f
your ve hicl e, especia lly t he engine. Even if
the m ileage on the veh icle is low, do not ex­
c e ed th e tim e fo r th e ne xt serv ic e .
282

tires according to the load and
the size of the tires installed.
Wheels
Tire pressure
Model/ Tire designation Normal load Maximum load
Engine (up to
2*/3 people)al
front
rear front rear
PSI kPA PSI kPA PSI kPA PSI kPA
A8/A8 L: 235/55 Rl8 104H
35 24
0
30 210
36 250
38 260
3.0L
255/45 Rl9 104H 35 240
30 210 36 250 38 260
6 cylinders 265/40 R20 104H 35 24
0
30 21
0
36 2
50
38 26
0
265/40 R20 104V 35 240
30 210 33 230 35 240
265/35 R21 101 Y 38 260
35 240
36 250
38 2
60
275/35 R21103Y 35 240
30 210 36 250 35 240
A8/A8 L: 235/55 Rl8 104H 36 250 30 210 38 260 38 2 60
4.0L
255/45 Rl9 104H 36 250 30 210 38 260 38 260
8 cylinders 265/40 R20 104H 36 250 30 210 38 260 38 260
265/40 R20 104V 36 250 30 210 35 2
40
35 2
40
275/35 R21 103V 36 250 30 210 38 260 38 260
58: 265/40 R20 104V 36 25 0 30 210 3 9 27
0
38 260
4.0L
265/35 R21101 Y 39 270 33 230 44 300 42 290
8 cylinders 275/35 R21 103V 36 250 30 210 44
300 42
290
58 plus: 265/40 R20 104V 38 260 32 220 39 270 38 260
4.0L
275/35 R21 103V
8
cylinders 45 310 39 270 49 340 48 330
a ) Vehicles with 4 seating positions: two people in the front, Vehicles with 5 seating
positions:
two people in the front, one person in the rear
A WARNING
Please note the important safe­
ty precautions regarding tire pressure
c:::> page 293 and load
limits
c:::> page 295.
Tires and vehicle load limits
There are limits to the amount of
~ load or weight that any vehicle that
is overloaded will not handle
well and is more difficult to stop.
Overloading can not only lead to
loss of vehicle control, but can al­
so damage important parts of the
vehicle and can lead to sudden
tire failure, including a blowout
and sudden deflation that can
cause the vehicle to crash.
N
~ and any tire can carry. A vehicle
0 0 :c ' Your safety and that of your pas­
sengers also depends on making
..,
295

u. co .... N
" N .... 0 0 :c ' may occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly . Always check the
TPMS malfunction telltale after replacing one or
more tires or wheels on your vehicle to ensure
that the replacement or alternate tires and
wheels allow the TPMS to continue to function
properly.
Description
Applies to: 58 plus
The tire pressure monitoring system monitors
the pressure in the four tires when driving.
The system uses sensors that measure the tem ­
perature and pressure in the tires . The data is
sent from these sensors to the control module by
radio frequency.
The Tire Pressure Monitoring System shows the
current pressures and temperatures of the tires
in the Infota inment system
c:> page 303 . It also
compa res the current tire pressures with the
stored tire press ures and gives a warning in the
driver information system if the tire pressure is
different from what is stored
c:> page 304.
The system does not detect if the stored tire
pressures match the recommended tire pres­
sures.
- Every time the tire pressures change, for exam-
ple when the load in the vehicle changes,
- after replac ing a tire, or
- if wheels with new wheel sensors are used,
you must store the tire pressures again
c:> page 304.
A WARNING
-The tire pressure mon itor ing system assists
the driver in monitoring tire pressures. The
dr iver is responsible for having the tires in­
flated to the correct pressure.
- Do not change the tire pressure when the
temperature of the tire is extremely high.
T his cou ld result in serious damage to the
t ir e and even cause the tire to burst, in­
creasing the risk of an accide nt.
Wheels
-A tire with low pressure flexes more . This
heats the tire up too much. This could cause
the tread to separate and even cause the
tire to burst, increasing the risk of an acci­
dent.
- The Tire Pressure Monitoring System does
not warn you of damage or defects in the
tire construct ion that could cause the tire to
burst, for example. Inspect your tires regu­
larly.
@ For the sake of the environment
Low tire pressure increases fuel consumption
and tire wear.
(D Tips
-The pressure of the spare t ire* is not mon i­
tored.
- If tires are replaced, the sensors/va lves do
not need to be removed or replaced. Just re­
placed the valve stem and, if necessary, the
valve and the whee l electronics . If you have
questions, see an authorized Audi dealer or
authorized Audi Service Facility.
Displaying tire pressures/temperatures
Applies to: 58 plus
Requirement: the ignition must be switched on.
.. Select: the I CAR! funct ion button > Car systems
> Service & control > Tire pressure monitor >
Display tire pressure .
The current tire pressures are shown in green and
yellow numbers in the Infotainment system:
-Green: the current tire pressure and the spec i­
fied tire pressure are approx imately the same .
-Yellow: the current tire pressure is too low
compared to the specified tire pressure .
The specified tire pressure is the last tire pres ­
sure that was stored
c:> page 304 .
Note that the tire pressure also depends on the
temperature of the tire . The tire pressure in­
creases as the engine becomes warmer while
driv ing.
.,.
303

lL t:0 ....
'"" ......
'"" .... 0 0 :c ' Driver's side cockpit fuse assignment
Fig. 286 Drive r side cockpit: fuse panel with plastic bracket
Fuse panel @ (brown)
No. Equipment
1 Light switch
2 Eme rgency start coil (driver iden tification)
3 Left rear door control module
4 Head-up display
5 Horn
6 Interior lights (headliner)
Steering column lever, multifunction
8 steer ing whee l controls, steering wheel
heating
10 Powe r steering column adjustment
11 Driver door control module
12 Diagnostic con nector, light/rain sensor
14 Power steering column adjustment
lS Power steering, A/C compressor
16 Brake booster
Fuse panel © (black)
No. Equipment
1 Front seat heating
2 Windshield wipers
Fuses and bulbs
Fuse panel © (black)
3 Front exterior lighting
4 Sliding/tilting sunroof
5 Driver power window
6 Dr iver 's seat (pne umat ic)
7 Panorama glass roof
8 Dynamic steering
9 Front exterior lighting
10 Windshield/headlight washer system
11 Left rear power window
12 Panorama glass roof
Front passenger side cockpit fuse
assignment
Fig. 287 Fro nt passe nge r side cockp it: fuse panel with
plastic bracket
Fuse panel @ (black)
No. Equipment
1 Anti-theft alarm system
2 Transmission contro l module
3 Front climate control fan
4 Engine s upply
6 Engine control module
7 Front passenger door control module
323

Fuses and bulb s
Bulbs
Replacing light bulbs
For your safety, we recommend that you have
your authorized Audi dealer replace burned out
bulbs for you .
It is becoming increasingly more and more diffi­
cult to replace vehicle light bulbs since in many
cases, other parts of the car must first be re­ moved before you are able to get to the bulb .
This applies espec ially to the light bulbs in the
front of your car wh ich you can only reach
through the engine compartment .
Sheet metal and bulb ho lders can have sharp
edges that can cause ser ious cuts, and parts
must be co rrectly taken apart and then p roperly
put back together to help prevent breakage of
parts and long term damage from water that can
enter housings that have not been properly re ­
sea led.
F or your safety, we recommend that you have
your authorized Audi dealer replace any bu lbs for
you, since your dealer has the proper tools, the correct bulbs and the expertise.
Ga s di sc ha rge la mp s (Xe non ligh ts):
Due to the high electrical voltage, have the bulbs
replaced by a qua lified techn ic ian . Head lights
with Xenon light can be identified by the high
voltage sticker.
LED headlights* requ ire no maintenance. P lease
contact your authorized Aud i dealer if a bulb
needs to be replaced.
A WARNING
Contact w it h high -vo ltage components of the
electrical system and improper rep lacement
of gas disc harge (Xenon) head light bu lbs can
cause serious personal injury and death.
- Xenon bulbs are pressurized and can ex ­
plode when being changed.
- Changing Xenon lamps requires the special
training, instructions and equipment.
- Only an a uthorized Audi dea ler or other
qualified workshop s hou ld change the bulbs
in gas disc harge lamps .
326
A WARNING
There are parts with sharp edges on the open­
ings and on the bulb holders that can cause
serious cuts .
- If you are uncertain about what to do, have
the work performed by an author ized Audi
dealer or other qual ified workshop . Ser ious
pe rsonal inju ry may resu lt from improperly
pe rformed wor k.
(D Tips
- If you must replace the light bulbs yourself,
always remember that the eng ine compart­
ment of any vehicle is a hazardo us a rea to
work in. Always read and heed all WARN­ INGS
~ page 272.
-It is best to ask you r author ized Audi dea le r
w henever you need to change a bulb.