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 G12++ antifreeze
with anticorrosion additives (50% for USA
models; 60% for Canadian models). This mix
ture both assures 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 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 antifree ze 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 ( -3 5 °C) USA
- -40 °F ( - 40 °C) Canada.
You can mix the G12 ++ coolant additive with
other additives (G12+ or G12). Always check
with your authorized Audi dealer.
& WARNING
Before you check anything in the engine
compartment, always read and heed all
WARNINGS
~ .&. in Working in the engine
compartment on page 216.
(D Note
- Before winter sets in, have the coolant
checked to see if the coolant additive in
Checking and filling 223
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++ (check the label) for your
vehicle. This coolant additive is availa
ble at authorized Audi dealers. Other
types of antifreeze can significantly re
duce corrosion protection. The result
ing corrosion can cause a loss of cool
ant and serious 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.
M AX f
MINf
Fig. 172 Engine compar tment: markings on the coo l
an t expa nsion tank
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 216 .
"' Park your vehicle on a level surface .
"' Switch off the ignition.
"' Read the engine coolant level from the
coolant expansion tank~
fig. 172. With a
224 Check ing and filling
cold engine, the coo lant level should be be
tween the "min" and "max" markings. When
the engine is warm, the level may be s light ly
above the "max" marking.
The location of the coolant expansion tank
can be seen in the engine compartment illus
tration
c:> page 218.
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 15 will
i l lum ina te unti l you add coolant and the level
has been restored to normal. Even though
there is an electric coolant level senso r, we
still recommend you check the coolant leve l
from time to time.
Coolant los s
Coolant loss may indicate a leak in the cool ing
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.
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 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 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 certain cond i
tions, the ethylene glycol in engine coo l
ant can catch fire.
(D Note
Do not add any type of radiator leak sea l
ant to your vehicle'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 W ARN
INGS c:> A in Working in the engine compart
ment on page 216 .
.. Turn off the engine.
.. Let the engine cool down.
.. Place a thick rag over the coolant expansion
tank
c:> page 223, fig . 172 and carefully
twist the cap co unte r-clockwise c:> .&, .
.,. Add coolant .
.,. Twist the cap on aga in
tightly.
Replacement engine coo lant must conform to
exact spec ificat ions
c:> page 223, Coolant.
E ven in a n emerge ncy, if coolant add i-
t ive G12 ++, G 12+ or G12 is not available, do
not use a d iffe rent addit ive. Use plain water
instead unti l you can get the correct additive
and can restore the correct ratio . This shou ld
be done as soon as possible.
If you have lost a considerab le amount o f
coolant, then you sho uld add cold antifreeze
and co ld water on ly w hen the engine is cold.
Always use
new engine coo la nt whe n refilling.
Do not fill coola nt above the "MAX" mark . Ex
cess coola nt will be fo rced out through the
pressure relief valve in the cap w hen the e n-
gine becomes hot. .,.
