244 Checking 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-basedcoolant additive G12++ antifreeze
with anticorrosion add itives (SO% for USA
models; 60% for Canadian models). This mix
ture bo th assures the necessary frost protec
tion and protects metal components in the
engine's coo ling 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, antifree ze is added at
the factory for temperatures down to:
- - 31°F (- 35 °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 ¢
A in Working in the engine
compartment on page 237.
(D Note
- Before winter sets in, have the coolant
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 extreme ly 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
b le at authorized Audi dealers . Other
types of antifreeze can significant ly 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.
Add ing radiator repair fluid may adverse
ly affect the function and performance of
your cooling system and cou ld resu lt 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. 206 E ngin e compart men t: Coo lant expans ion tank
.,. Before you check anything in the engine
compartment,
always read and heed all
WARNINGS ¢&. in Working in the engine
compartment on page 23
7.
.,. Turn off the ignition .
.,. Read the engine coolant level from the
coo lant expansion tank¢
fig. 206. With a
cold engine, the coolant level should be be-
tween the "MIN" and "MAX" markings . ..,..
When the engine is warm, 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 239.
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
31 will
blink until you add coolant and the level has
been restored to normal. Even though there is
an electric coolant level sensor, we still rec
ommend 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 245
@ 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 23
7.
.,. Turn off the engine .
.,. let the engine cool down.
.,. Place a thick rag over the coolant expansion
tank ¢ page
244, fig . 206 and carefully turn
the cap counter-clockwise ¢
&_.
.,. Add coolant.
.. Twist the cap on again tightly.
Replacement engine coolant must conform to
exact specifications ¢ page
244, Coolant.
Even in an emergency, if coolant addi-
tive G12++, G12+ or G12 is
not available, do
not use a different additive. Use plain water
instead 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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