engine overheat AUDI A5 CABRIOLET 2014 User Guide

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 specially conditioned water and the
manufacturer's glycol-based coolant addi-
tive G13 antifreeze with anticorrosion addi­ tives (50% for USA models; 60% for Canadian models). This mixture both assures the neces­
sary frost protection and protects metal com­
ponents in the engine's cooling system from
corrosion and scaling.
It also raises the boil­
ing point of the coolant.
Do not reduce the concentration of the cool­
ant in the summer by adding plain water.
The
proportion of coolant additive must be at
least 50% but not more than 60%
to main­
tain antifreeze protection and cooling efficien­
cy. If the coolant frost protection is too low,
the coolant could freeze and damage the vehi­ cle heating and engine cooling system.
For year-round driving, antifreeze is added at
the factory for temperatures down to:
- -31°F(-35°C)USA
- -40 °F ( - 40 °C) Canada.
If you must add coolant, use a mixture of wa­
ter and coolant additive. Mixing the coolant
additive with distilled water is recommended.
& WARNING
Before you check anything in the engine
compartment, always read and heed all
WARNINGS¢ .&.
in Working in the engine
compartment on page 206.
(D Note
- Before winter sets in, have the coolant
checked to see if the coolant additive in
Checking and filling 213
your vehicle is sufficient to meet the cli­
mate conditions. This is especially impor­
tant if you live in a region where the win­
ter is extremely cold. If necessary, in­
crease the proportion of coolant additive
to 60%.
- When adding coolant additive to your
cooling system, remember:
- We recommend using only coolant ad­
ditive G12++ or G13 for your vehicle.
This coolant additive is available at au­
thorized Audi dealers. Other types of
antifreeze can significantly reduce cor­
rosion protection. The resulting corro­
sion can cause a loss of coolant and se­ rious engine damage.
- Do not add any type of radiator leak seal­
ant to your vehicle's engine coolant.
Adding radiator repair fluid may adverse­
ly affect the function and performance of
your cooling system and could result in
damage not covered by your New Vehicle
Limited Warranty.
Checking the engine coolant level
The engine coolant level can be checked with
a quick glance.
Fig. 178 Eng ine compartment: Cover on the coolant
expansion tank
"' Before you check anything in the engine
compartment,
always read and heed all
WARNINGS ¢ .&, in Working in the engine
compartment on page 206.
"'Park your vehicle on a level surface .
.,. Turn off the ignition.
.,. Read the engine coolant level from the cool­
ant expansion tank ¢
fig. 178, ¢ page 208,
fig. 175.
With a cold engine, the coolant Iii>

214 Check ing and filling
level should be between the "MIN" and
"MAX" markings. When the engine is warm,
the leve l may be slightly above the "MAX"
marking .
The location of the coolant expansion tank
can be seen in the engine compartment illus­
tration
c:> page 208.
To obtain an accurate reading, the engine must be switched
off.
The expansion tank in you r vehicle is equipped
with an e lectric coolant level sensor.
When the coolant level is too low, the warning light in the Auto-Check System
c:> page 17will
b link until you add coo lant and the level has
been restored to no rma l. Even though there is
an electric coolant level sensor, we still rec ­
ommend you check the coolant leve l from
time to time.
Coolant loss
Coolant loss may indicate a leak in t he cool ing
system. In the event of coolant loss, the cool ­
ing system should be inspected immediately
by your authorized A udi dealer.
It is not
enough merely to add coolant.
I n a
sea led system, losses can occur only if
the boiling point of the coolant is exceeded as
a result of overheat ing.
A WARNING
The cooling system is unde r 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
dow n.
- Protect yo ur 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 wh ile ap­
plying light, downward pressure on the
top of the cap .
- To avoid be ing burned, do not spill ant i­
freeze or coolant on the exhaust system
'
or hot engine parts. Under certa in cond i­
tions, the ethylene glycol in engine coo l­
ant can catch fire.
(D Note
Do not a dd any type of radiator leak sea l­
ant to your veh icle's engine coolant. Add ­
i ng radiator repa ir fl uid may adverse ly af­
fect the funct ion and performance of your
cooling system and could result in damage
not covered by your New Veh icle L imited
War ranty .
Adding coolant
Be very careful when adding engine coolant.
Before you check anyth ing in the eng ine com­
partment,
always read and heed all WARN­
INGS c:> A in Working in the engine compart­
ment on page 206 .
Requirement: There m ust be a res idual
amount of coo lant in the expans ion tank
c:> (]) .
.,.. Turn off the eng ine .
.,.. Let the engin e cool down.
.,.. Place a thick rag over the coo lant expansion
tank
c:> page 213 , fig. 178 and carefully turn
the cap counter-clockwise
c:> .&_ .
.,.. Add coo lant m ixed in the correct rat io
c:> page 213, Coolant up to the MAX ma rk­
ing.
.,.. Mak e s ure t hat the fl uid leve l remains sta-
b le. Add more coo lant if necessary.
.,.. Twist the cap on again
tightly .
Replacement engine coo lant must confo rm to
ex act spec ific at ions
c:> page 213, Coolant.
We recommend using only coolant add it ive
G12 ++, G13 or i n an emergency G 12+. Do
not
use a different add it ive. In an emergen cy use
plain wa ter until yo u can ge t the correct addi­
tive and can restore t he correct ratio. This
sho uld be done as soon as possib le .
If you have los t a cons iderab le amount o f
coolant, the n you sho uld add cold ant ifree ze
and co ld wate r on ly when the engine is cold.
Always use
n ew engine coo la nt w hen refilling . .,.