2018 AUDI A8 engine overheat

Cockpit overv iew
CD Note
- Auxiliary headlights and other accessories in
front of the cooling-air intake impair the
cooling effect of the coolant. This increases
the r isk of the engine overheat ing during
high outside temperatures and heavy en-
gine load.
- The front spoiler also helps to distr ibute
cooling air correctly wh ile driving. If the
spoiler is damaged, the cooling effect will
be impaired and the risk of the engine over­
heating will inc rease. See an a uthorized
A ud i dealer or authorized Audi Service Fa­
cility for assistance .
Tachometer
The tachometer displays the engine speed in rev ­
olutions per minute
(RPM).
You should shift to the next lowest gea r when
the speed is below 1,500 RP M. The beginn ing of
the red zone in the tachometer ind icates the
maximum permissible engine speed fo r all gears
once the engine has been broken in and when it is
warmed up to operating temperature . Before
reaching this zone, you should shift into the next
highest gear, select the D selector lever position,
or remove your foot from the accelerator pedal.
~ Note
The needle in the tachometer @ c:> page 9,
fig. 3 may only be in the red area of the gauge
for a short time or there is a risk of engine damage. The locat ion where the red zone be­
gi ns varies depending on the engine.
@ For the sake of the environment
Upshifting early helps you to save fuel and re­
duces operating noise.
Fuel level
The display @ only works when the ignition is
sw itched on. If the fuel level drops below 4 gal
(15
L), a red L ED will light up and the Ill indica­
tor light will turn on
c:> page 24. The red LED
will blink when the fuel level is very low.
10
The fuel tank capacity of your ve hicle is listed in
the
Techn ical Data section c:> page 334.
CD Note
Neve r drive until the tank is comp letely emp­
ty. The irregu lar supply of fuel th at results
from that can cause engine misfires . Uncom­
busted fuel w ill then enter the exhaust sys­
tem. This can cause overheating and damage
to the catalyt ic converter.
Odometer
Fig. 4 Instru ment cluster: odometer and reset button
Upper odometer
The trip odometer shows the distance driven
s ince it was last reset.
It can be used to measure
short distances.
The trip odometer can be reset to zero by press ­
ing
the ~ reset button.
Lower odometer
The lower odomete r shows the total distance
that the vehicle has driven.
Malfunction indicator
If there is a malfunction in the instrument clus­
ter,
DEF will appear in the trip odometer display.
Have the malfunction corrected as soon as possi­
ble.

lL t:0 ....
"" ......
"" .... 0 0 :c ' Save en er gy
The engine drives the generator, wh ich generates
electricity; the fue l consumption also increases
with the demand for electricity. Therefore, switch
e lectrical equipment off when you no longer
need it. Examples of equipment that use a lot of
energy are air blowers at a high setting, the rear
window defogger and seat heating*.
CD Note
Do not leave engine idling unattended after
starting. If warning lights should come on to
ind icate improper operation, they would go
unheeded. Extended idling also produces
heat, wh ich could result in overheat ing or
other damage to the vehicle or other p roper-
ty.
CD Note
-Have your vehicle maintained properly and
i n accordance with the service recommenda­
tions in your Warranty
& Ma intenance book­
l et. Lack of proper maintenance as well as
i mproper use of the vehicle will impair the
function of the emission control system and
could lead to damage.
-Do not alter or remove any component of
the Emission Control System unless ap­ proved by the manufacturer.
-Do not alter or remove any device, such as
heat shie lds, switches, ignition wires,
valves, which are designed to protect your
vehicle's Emission Control System and other
important vehicle components .
@ Tips
The consumption estimates as published by
ENVIRONMENTAL PROTECTION AGENCY
(EPA) and Transport Canada may not corre­
spond to your actual consumption on the
road, which will vary depending upon vehicle
load and speed, road and weather conditions
trip length, etc.
'
D rivi ng
Steering
Adjusting the steering wheel position
The steering column can be power adjusted up
and down and forward and back.
F ig . 89 Sw itc h for steering colu mn adjustment
Requirement: the driver's seat is set correct ly.
"' To adjust the he ight, press the sw itch up/down .
The steering co lumn will continue movi ng as
long as you are pressing the switch.
"' To move the steering wheel forwa rd or back,
press the switch forward/back. The steering
column will continue moving as long as you are
pressing the switch.
T he steering wheel can a lso be adjusted when the
ignition is switched off .
In veh icles with memory function*, the steering
co lumn settings are s to red toget her w ith the
seat position.
A WARNING
Improper use of steering wheel adjustment
and improper seating position can cause seri­
ous personal injury.
- Adjust the steering wheel column only when
the vehicle is not moving to prevent loss of
veh icle control.
- Ad just the driver's seat or steer ing whee l so
that the re is a m inimum of 10 in (25 cm)
between your chest and the steering wheel
r::;, page 209, fig . 217 . If you cannot main­
tain this minimum distance, the airbag sys-
tem cannot protect you p roperly.
~
75

Driving
keep your foot on the brake in all selector
lever positions (except P and N) when the
engine is running.
- Do not inadvertently press the accelerator
pedal when the vehicle is stationary. Other­
wise the vehicle will start to move immedi­
ately, even if the parking brake is set. This
could result in a crash.
~ Note
-When stopping on an incline, do not try to
hold the vehicle in place by pressing the ac­
celerator pedal while a driving gear is se­ lected . This can cause the transmission to
overheat and can damage it . Set the parking
brake or press the brake pedal to prevent
the vehicle from rolling.
- Allowing the vehicle to roll when the engine
is stopped will damage the transmission be­
cause it is not lubricated.
(D Tips
For safety reasons, the parking brake is re­
leased automatically only when the driver's
safety belt is fastened.
Hill descent control
The hill descent control system assists the driver
when driving down hills .
Hill descent control activates when the transmis­
sion is in the Dor S position and you press the
brake pedal. The transmission automatically se­
lects a gear that is suitable for the hill. Hill de­
scent control tries to maintain the speed ach­
ieved at the time of braking, within physical and
technical limitations. If may still be necessary to
adjust the speed with the brake pedal.
Hill descent control switches off once the hill lev­
els out or you press the accelerator pedal.
When operating the cruise control system
c::> page 93, hill descent control is also activated
when the speed is set.
86
A WARNING
, -
Hill descent control cannot overcome physical
limitations, so it may not be able to maintain
a constant speed under all conditions. Always
be ready to apply the brakes .
Manual shifting
The shi~ paddles allow the driver to shift the
gears manually.
Fig. 98 Steering whee l: shi fting manually
.. To shift to a higher or lower gear temporarily,
tap the
0 or 0 shift paddle <=:>fig. 98.
.. To switch manual mode on, press the ~ but­
ton. Mand the gear that is currently engaged
@ appear in the instrument cluster display
c::> page 83, fig. 95 .
.,. To shift up one gear, tap the right shift paddle
G) c::>fig . 98.
.,. To shift down one gear, tap the left shift pad­
dle
0 .
.,. To switch manual mode off, press the ['.fl but-
ton again, or
.. Move the selector lever back and release it.
When you accelerate or reduce the speed, the
transmission automatically shifts into the correct
gear shortly before reaching the RPM limit. If you
select a lower gear than the one currently shown
in the display, the automatic transmission will
only shift down once there is no danger of ex­
ceeding the maximum RPM.
The engine braking effect increases when you
downshift when going downhill.

Trailer towing
Trailer load distribution
Be sure the load in the trailer is held securely in
p la ce to prevent it from shifting forward, back­
ward or sideways .
Never allow a passenger to ride in a trailer~&.
in Driving instructions on page 91.
Engine cooling system
Towing a trailer makes the engine work harder . It
is important that the coo ling system's perform­
ance is up to t he additional load. Make sure that
the cooling system has eno ugh fluid .
Tire pressure
When tow ing a tra iler, inflate the tires of your
veh icle to the tire pressure listed under "Full
load " on the label
~ page 293. Inflate trailer
tires to trailer and tir e ma nufactu rers' specifica­
tions.
Lights
Check to make sure both vehicle and trailer lights
are working properly .
Safety chains
Be sure trailer safety chains are proper ly connect­
ed from the trailer to the hitch on the vehicle.
Leave enough slack in the chains to permit turn­
ing corners . When you install safety cha ins, make
sure they w ill not drag on the road when you are
driving.
The chains should cross under the trailer tongue
to prevent it from dropping in case of separation
from the hitch .
Adjusting the Audi drive select
Make sure the vehicle is on a level surface before
hitching up the trailer and before adjust ing the
tongue we ight. The vehicle must be in
auto or
comfort driving mode and not ra ised
~ page 111, ~0 .
Make sure that the vehicle is lowered. In Info­
tainment, select:
ICARI function butto n> Lower
control button.
90
If you must drive under poor road conditions, you
can raise the ve hicle
after coupling the trailer or
after adjust ing the tongue we ight ~ page 113.
@ Note
-Changes in temperature or load can aff ect
the height of the vehicle .
-Always select auto or comfort mode. Other­
wise, the tong ue load specified for your ve­
hicle will no longer be applicab le .
Driving instructions
Driving with a trailer always requires extra care
and consideration.
Weight distribution
Towing a loaded trailer with an empty car results
in a hig hly unstable distribution of we ight. If th is
cannot be avoided, drive at very low speeds only
to avoid t he risk of losing steering contro l.
A "balanced" rig is eas ier to operate and control.
This means that the tow vehicle s hould be loaded
to
the extent possible and permissib le, w hil e
keeping the trailer as light as possible under the
circumstances. Whenever possible, transfer
some cargo to the luggage compartment of the
tow veh icle while observing tongue load require­
ments and vehicle loading considerations.
Speed
The higher the speed, the more difficu lt it be ­
comes 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 cond it ions are unfavorable - particularly whe n
go ing down hill.
Reduce vehicle speed
immediately if the trailer
shows the slightest sign of sway ing.
Do not try
to stop the swaying by accelerating.
Observe speed limits. In some areas, speeds for
vehicles towing trailers are lower than for regular
vehicles.
A lways apply brakes early. When driving down­
hill, shift into a lower gear to use the engine
braking effect to slow the vehicle. Use of the
brakes alone can cause them to overheat and fail.
ll-

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 .