2012 AUDI A8 engine overheat

& WARNING
-Never let the vehicle roll to a stop with
the engine shut
off.
- If the brake booster is not working, for
example when towing your vehicle, or
because the brake booster has somehow
been damaged, the brake pedal must be
pressed considerably harder to make up
for the lack of booster assistance.
Servotronic ® -
advanced power
steering system
-
The power steering systems use the power of
the running engine to allow precise steering
with little effort.
The advanced Servotronic ® power steering
system senses the road speed and e lectroni­
cally adjusts power ass istance to provide com­
fortable and safe steering response exactly matched to the veh icle speed.
Power steering wi ll not work if the engine is
off. As a resu lt, the steering whee l wi ll be hard
to turn.
The power steering fluid level is checked dur­ ing the scheduled maintenance services.
(D Note
I f there is an electronic malfunct ion, ser­
votronic
will sti ll function like a conven­
tional power steering system, providing a
constant steering support force that is no
longer proportionate to the vehicle speed.
This is most noticeable when turning the steer ing whee l at low speeds (for examp le
when parking), -more effo rt will be re­
qui red than usual.
- Be awa re of the different than usual
steering response and adjust your stee r­
i ng fo rce accord ingly.
- Have the p roblem checked and set right
by an Aud i dealer as soon as possib le .
Int ellig ent technolog y 191
(D Tips
-When the engine is running, never ho ld
the steering wheel turned all the way to
the right or to the left for longer than 15
seconds. The power steering pump will
overheat the hydrau lic fluid if you keep
holding the stee ring wheel turned all the
way. This is likely to damage the power
steering system.
- If the powe r stee ring system should fa il
entire ly, o r if the e ngine is not run ning
(for example, wh ile be ing towed), you
w ill still be able to stee r the veh icle.
However,
considerably more effor t will
be required to do so .
- If the power stee ring system sho uld
have a lea k, or is not functioning proper ­
ly, contact your authorized A udi dealer
immediately.
- The power steering system req uires a
specially formu lated hydra ulic fluid. The
power steering fluid reservoir is located
in the engine compartment
Q page 221.
The correct fluid level in the reservoir is
important for proper functioning of the
powe r stee ring.
Driving with your
quattro ®
With All Wheel Drive, all four wheels ore driv­
en.
General information
Wi th A ll Wheel Drive, power is dis tributed to
all four w heels. This happens automatically
depend ing on your driving style and the road
conditions at the time . See a lso
Q page 187.
With the sport different ia l*, power distribu­
tion to the rear wheels is variable and can be
adjusted with Audi drive select*
Qpage 103.
Always read and follow safety precautions
Q&_ ,
Winter tires
When dr iving in the winter, yo ur vehicle with
A ll Wheel Drive has an advantage, even w ith
regular tires. In winter road conditions it may ..,. •
•

Catalytic converter
It is very important that your emission con­trol system (catalytic converter) is function­
ing properly to ensure that your vehicle is run­
ning in an environmentally sound manner .
.. Always use lead-free gasoline¢ page 215,
Fuel supply.
.,. Never run the tank down all the way to
empty.
.,. Never put too much motor oil in your en-
gine
¢ page 225, Adding engine oil~-
.,. Never try to push- or tow-start your veh icle.
The catalytic converter is an eff icient "clean­
up" device built into the exhaust system of
the vehicle . The catalytic converter burns
many of the pollutants in the exhaust gas be ­
fore they are released into the atmosphere.
The exclusive use of unleaded fuel is critically
importa nt for the life of the cata lytic convert­
e r and proper functioning of the engine.
A WARNING
-
- Do not park or operate the vehicle in
areas where the hot exhaust system may
come in contact with dry grass, brush,
fuel spill or other material which can cause a fire.
- Do not apply additional undercoating or
rustproofing on or near the exhaust
man ifold, exhaust pipes, catalytic con­
verter or heat shields. During driving, the
substance used for undercoating cou ld
overheat and cause a fire.
0 Note
- Be aware that just one tank filling with
leaded fuel will already seriously de­
grade the performance of the catalytic
converter.
- Do not exceed the correct engine oil level
¢ page 225.
-Do not drive until the fuel tank becomes
completely empty. The eng ine could mis­
fire . U nburned fuel could a lso get i nto
Dri vin g and en vironm ent 195
the exhaust system and this cou ld cause
the catalytic converter to overheat .
- Do not switch off the ignit ion while the
vehicle is mov ing.
- Do not continue to ope rate your veh icle
unde r these conditions, as othe rwise fuel
can reach the catalytic converter. This
co uld result in overheating of the con­
verter, requir ing its replacement .
- To assure efficient operation of the Emis ­
sion Control System:
- H ave your vehicle maintained prope rly
and in accordance w ith the se rv ice rec­
ommendat ions in you r Warranty &
M aintenance boo klet.
- L ack of prope r maintenance as we ll as
improper use of the vehi cle w il l impair
the function of the em ission contro l
system and could lead to damage .
@ For the sake of the environment
Even when the Emiss ion Control System is
operat ing properly, the exha ust gas can
have a sul fur -li ke exhaust gas smell under
some operating states . This depends on
the sulfur content of the fuel being used .
Using a different brand of fue l may help,
or filling the tank with lead-free super
grade gasoline .
Avoid damaging the
vehicle
When you are drivi ng on poo r roads, or over
c ur bs, s teep ramps, etc., ma ke certai n that
low -lying parts s uch as spoilers and exhaust
system pa rts do not bottom o ut and get dam­
aged.
T h is is espec ially true for veh icles w ith low­
s lung chassis (spor ts chassis)* and fully load­
ed vehicles. •
•

drive at the maximum permissible speed. Re­
duce your speed even more if load, weather or
wind condit ions are unfavorable -part icularly
when going downhill.
Reduce vehicle speed
immediately if the trail­
er shows the slightest sign of swaying .
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
downhill, shift into a lower gear to use the en­
gine braking effect to slow the vehicle . Use of
the brakes a lone can cause them to overheat
and fail.
Coolant temperature
The coolant temperature gauge c:> page 10
must be observed carefully. The coo lant tem­
perature can increase if you drive on long in ­
clines in a low gear at high engine speeds. Re­
duce your speed immed iate ly if the L EDs in
the top part of the display turn on.
F or more information about indicator lights,
refer to.
i::> page 15.
A WARNING
Anyone not properly restrained in a mov­
ing vehicle is at a much greater risk in an
accident . Never let anyone r ide in your car
who is not properly wear ing the restra ints
provided by Aud i.
Trailer towing tips
Important to know
Your veh icle hand les different ly when tow ing
-
a trailer because of the addit ional weight and
d ifferent weight distribution . Safety, perform­
ance and economy will greatly depend on how
carefully you load your trailer and operate
your ng .
Before you actually tow your trailer, practice
turning, stopp ing and back ing up in an area
away from traffic. Keep practicing until you
Trailer towing 201
have become completely familiar with the way
your vehicle-trai ler combination behaves and
responds .
Backing up is difficult and requires practice .
Backing up with a t railer generally requires
steering action opposite to that when backing
up your vehicle without a tra iler.
Maintain a greater distance between your ve­
hicle and the one in front of you . You wi ll need
more room to stop. To compensate for the
trailer, you w ill need a larger than normal
turning rad ius.
When passing, remembe r that you cannot ac­
ce lerate as fast as you norma lly would be­
cause of the added load. Make sure you have
enough room to pass. After passing, allow plenty of room for your trailer before chang­
ing lanes again.
Avoid jerky starts, sharp turns or rapid lane changes.
(D Tips
- Do not tow a trailer during the break-in
period of your vehicle.
- If you tow a trailer, your Audi may re ­
quire more frequent maintenance due to
the extra load
c:> page 280.
Parking on a slope
Do not park on a slope with a trailer. If it can­
not be avoided, do so only a~er doing the fol­
lowing:
When parking:
.,. App ly the foot brake.
.,. Have someone p lace chocks under both the
vehicle and the trailer wheels .
.,. With chocks in place, slowly release the
brakes until the wheel chocks absorb the
load.
.,. Turn the wheels towards the curb .
.,. Apply the parking brake .
.,. Select the P selector lever posit ion .
When restarting after parking:
.,. Apply the foot brake.
•
•

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 ..,_