2015 AUDI A8 engine overheat

212 Trailertowing
drive at the maximum permissible speed. Re­
duce your speed even more if load, weather or
wind condit ions are unfavorable -part icu larly
when going downhill.
Reduce vehicle speed
immedi atel y if the trail ­
er shows the slightest sign of swaying .
Do not
tr y to stop th e sway ing by acceler ating .
Observe speed limi ts. In some areas, speeds
for vehicles towing trailers are lower than for
regular vehicles .
A lways apply brakes early. When driv ing
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 t emperature
The coolant temperature gauge¢ page 10
must be observed carefully. The coolant tem­
perat ure can increase if you drive on long in ­
clines in a low gear at high engine speeds. Re­
duce your speed immediate ly if the L EDs in
the top part of the display turn on.
F or more in formation about indicator lights,
referto .¢page
15 .
A WARNING
Anyone not properly restrained in a mov­
ing veh icle is at a much greater risk in an
accident . Never let anyone ride in your car
who is not properly wear ing the restra ints
provided by Aud i.
Trailer towing tips
Important to know
Your vehicle hand les different ly when towing
-
a trailer because of the addit ional weight and
d ifferent weight distribution . Safety, perform­
ance and economy w ill 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 have become completely familiar with the way
your vehicle-trailer combination behaves and responds .
Backing up is diffi cult and requ ires practice .
Backing up with a trailer gene rally req uires
steering action opposite to that when backing
up your vehicle without a tra iler.
Maintain a greater d ista nce between you r 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, remember that you cannot ac ­
ce lerate as fast as you norma lly would be­
ca use of the added load. Make sure yo u have
enough room to pass. After passing, allow
plenty of room for your trailer be fore 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¢
page 290.
Parking on a slope
Do not park on a slope with a trailer. If it can­
not b e avoided, do so only after doing th e fol­
lowing:
When par king:
.,. App ly the foot brake.
.,. Have someone p lace chocks under both the
vehicle and the tra iler wheels .
.,. With chocks in place, slowly release the
brakes unt il the wheel chocks absorb the
load .
.,. Turn the whee ls towards the curb .
.,. Apply the parking brake .
.,. Select the P se lector lever posit ion.
When re starting after parking:
.,. App ly the foot brake.

236 Check ing and filling
@ For the sake of the environment
- Before changing your oil , first make sure
you know where you can properly dispose
of the used oil.
- Always dispose of used engine oil proper­
l y. Do not dump it on garden soi l, wood­
ed areas, into open streams or down
sewage dra ins.
- Recycle used engine oil by taking it to a
used engine oil collection facility in your
area, or contact a service station .
Engine cooling system
Coolant
The engine coolant performs two functions: it
keeps the engine from overheating and it pro­ tects the engine from freezing in the winter.
The cooling system is sea led and generally re­
qu ires little attention .
The cooling system has been filled at the fac ­
tory with a pe rmanent coolant which does not
need to be c hanged. The coolant consists of a
mixture of spec ia lly conditioned water and the
manufacturer 's glycol-based coo lant add i-
tive G l3 antifreeze with ant icorrosion addi ­
tives (50% for USA models ; 60% for Canadian
mod els). This mixture both assures the nec es­
sary frost protection and protects metal com­ ponents in the engine's cooling sys tem from
corrosion and scaling . It a lso raises the boil­
ing point of the coolant .
Do not red uce the concentration of the coo l­
ant in the summer by adding plain water.
The
proportion of coolant add it ive mu st be at
l e a st 50 % but not more than 60 %
to main­
tain antifreeze protection and cooling efficien­
cy . If the coolant frost prote ct ion is too low,
the coo lant cou ld freeze and damage the veh i­
cle hea ting and eng ine cooling system.
For yea r-round d riving, antifreeze is added at
the fac to ry for temperatures down to:
-- 31°F( -35°C)USA
- -40 °F ( -40 °C) Canada. If
you must add coolant, use a mixture o f wa ­
ter and coolant additive . Mixing the coo lant
additive with distilled water is recommended.
A WARNING
-
Before you c heck anything in the engine
compartment, always read and heed a ll
WAR NINGS
c::, & in Working in the engine
compartment on page 228.
(D Note
- Before winter sets in, have the coo lant
checked to see if the coolant additive in
your vehicle is sufficient to meet the cli­ mate conditions . This is especia lly impor­
tant if you live in a reg ion where the win­
ter is ex treme ly cold. If ne cessa ry, i n­
crease the pr opo rtion of coo lant add itive
t o 60%.
- Whe n adding coolant additive to yo ur
c ooling sys tem, remembe r:
- We recommend using on ly coolant ad ­
d itive Gl2++ or Gl3 for your vehicle .
This coolant additive is availab le at au­
thor ized Audi dealers . Other types of
ant ifreeze can s ignificant ly reduce cor­
rosion protection. The resulti ng cor ro­
sion can ca use a loss o f coolan t and se­
rio us engine damage.
- Do not add any type of rad iator leak seal­
a nt to yo ur vehicle 's engine coolant.
Add ing radiator repai r fl ui d may adverse ­
ly affect the function and performance of
your cooling system and co uld resu lt in
damage not covered by yo ur New Vehicle
Limited Warranty.
-

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Checking the engine coolant level
The engine coolant level can be checked with
a quick glance .
Fig. 204 Eng ine compartme nt: cover o n the coolant
expansion tank
Before you check anything in the engine com­
partment,
a lway s read and he ed all WARN ­
INGS ¢ & in Working in the engine compart­
ment on page 228.
Park your vehicle on a level surface.
~ Switch off the ignition.
~ Read the engine coolant leve l from the cool­
ant expansion tank¢
fig. 204, ¢ page 230.
With a cold engine, the coolant level should
be between the "min" and "max" markings.
When the engine is warm, the level may be sl ightly above the ''max" marking.
The location of the coolant expansion tank
can be seen in the engine compartment illus­
tration ¢
page 230 .
To obtain an accurate reading, the engine
must be switched off.
The expansio n tank in your vehicle is equipped
with an electric coolant level sensor.
When t he coo lant level is too low, the warning
light in the Auto-Check System¢
page 15 will
illuminate unti l yo u add coolant and the level
has been restored to normal. Even thoug h
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-
Checkin g and fillin g 237
ing system shou ld be inspected immediately
by your authorized Audi dealer . It is not
eno ugh merely to add coo lant .
In a
s ealed system, losses can occu r on ly if
the boiling point of the coo lant is exceeded as
a resu lt of overheating.
A WARNING
The cooling system is under pressure and
can get very hot. Red uce the risk of scald­
ing from hot coolant by follow ing these
steps.
- Turn off the engine and allow it to cool
down.
- Protect your face, hands and arms from
escaping flu id a nd steam by cover ing the
cap with a la rge, th ick rag.
- Turn the cap slowly and very carefully in
a counter-clockwise d irect ion while ap­
p lyi ng lig ht, dow nward pressure on the
top of the cap.
- To avo id being burned, do not sp ill anti­
freeze o r coolan t on the exhaust system
or ho t engine parts. Und er certa in cond i­
tions, the ethylene gly co l in engine coo l­
an t can catch fire.
(D Note
Do not add any type of radiator leak sea l­
ant to your veh icle's engine coo lant. Add­
i ng radia to r repa ir flui d may adverse ly af­
fe ct the fun ct io n and perfor man ce o f you r
coo ling system and could result in damage
not cove red by your New Vehicle Limi ted
War ranty.
Adding coolant
Be very careful when adding engine coolant .
Before you che ck a nyt hing in the eng ine com­
partmen t,
alway s re ad and he ed alt WARN­
INGS ¢ & in Working in the engine compart­
ment on page 228.
~ Requirement: There must be a residua l
a mo unt of coolan t in the expansion ta nk
¢(D.
~Tu rnoff the engine . •
•