engine overheat AUDI A6 2013 User Guide

232 Check ing and filling
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 sealed and generally re­
quires 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 Gl3 ant ifreeze
with ant icorros ion add itives (50% for USA
models; 60% for Canad ian models). This mix­
ture both assu res the necessary frost protec­
tion and protects metal components in the
engine's cooling system from corrosion and
scaling. It also raises the boiling point of the
coolant.
Do not reduce the concentration o f the coo l­
ant in the summer by adding plain water .
The
propo rtion of coolant add it iv e mu st be at
l eas t 50 % but not mo re than 6 0%
to main­
tain antifree ze protection and cooling efficien­
cy. If the coolant frost protect ion is too low,
the coolant could 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:
- -31°F(-35°C)USA
- - 40 ° F ( -40 °C) Canada.
A WARNING
Before yo u check anything in the engine
compartment, always read and heed all
WARNINGS
c:> &. in Working in the engine
compartment on page 225.
- Before winter sets in, have the coolant
checked to see if the coo lant addit ive in
your vehicle is suffic ient to meet the cli­
mate cond itions. Th is is especially impor­
tant if you live in a region where the w in- ter is extreme
ly cold . If necessary, in ­
crease the proportion of coo lant additive
to 60%.
- When adding coolant additive to your
cooling system, remember:
- We recommend us ing only coolant ad­
d itive Gl2++ or G l3 (check the labe l)
fo r your vehicle. This coolant additive is
ava ilable at a utho rized Aud i dea le rs.
Other types of antifreeze can sign ifi­
cantly reduce corros ion protection. The
res ulting corrosion can cause a loss of
coolant and serious engine damage.
- Do not add any type of radiator leak seal ­
ant to yo ur vehicle's engine coolant .
Add ing radiator repair flu id may adverse­
ly affect the function and performance of
your cooling system and could resu lt in
damage not covered by your New Veh icle
Limited War ranty.
Checking the engine coolant level
The engine coolant level can be checked with
a quick glance .
Fig. 1 87 Engin e compar tmen t: cover on t he coo la nt
expansio n ta nk
Before you check anyth ing in the engine com­
partment,
alwa ys read and heed all WARN­
I NGS c:> &. in Working in the engine compart ­
ment on page 225 .
.. Park your vehicle on a level surface .
.. Switch off the ignition.
.. Read the engine coolant level from the
coola nt expansion tank
c:> fig . 187,
c:> fig. 184 . With a cold engine, the coolant
level shou ld be between the "min" and
"max" markings. When the eng ine is wa rm, ..,.

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 22 7.
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 16will
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 .
Checking and filling 233
@ 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 225 .
.,. Turn
off the engine .
.,. let the engine cool down.
.,. Place a thick rag over the coolant expansion
tank ¢ fig .
187 and carefully twist the cap
counter-clockwise ¢&_ .
.,. Add coolant.
.,. Twist the cap on again tightly.
Replacement engine coolant must conform to
exact specifications ¢ page
2 32, Coolant. We
recommend using only coolant additive G12+
+, G13 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.
A WARNING
- The cooling system is under pressure and
can get very hot. Reduce the risk of
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