engine overheat AUDI A8 2012 User Guide

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 ..,_