Checking and topping up fluids 260
Caution•
The oil level must never be above area ⇒page 258, fig. 254,
as this may result in damage to the catalytic converter or to the
engine. On vehicles without an oil dipstick, you can check the oil
level via the sound system or MMI*. Contact a qualified workshop to
extract the engine oil if necessary.
•
No additives should be used with engine oil. Any damage caused
by the use of such additives would not be covered by the factory
warranty.For the sake of the environment
•
Never pour oil down drains or into the ground.
•
Always observe statutory requirements when disposing of
empty oil canisters.
Cooling systemCoolant
The purpose of the coolant is to carry heat away from the
engine. The correct amount of anti-freeze is important to
prevent the cooling system from freezing in winter.The cooling system is filled for life at the factory, so the coolant does
not need to be changed. The coolant consists of a mixture of water
and anti-freeze additive G12++. This is a glycol-based anti-freeze
with anti-corrosion additives.
Anti-freeze additive
The amount of anti-freeze additive required depends on the temper-
atures to be expected in the winter season. If the anti-freeze concen-
tration is too low the coolant can freeze, resulting in failure of the
cooling system and heater.The cooling system is filled at the factory with the correct amount of
anti-freeze for the country concerned.
In most cases the mixture consists of 60% water and 40% additive.
This mixture gives the required anti-freeze protection at tempera-
tures down to -25 °C and protects the alloy parts of the cooling
system against corrosion. It also prevents scaling and raises the
boiling point of the coolant.
Countries with warm climate
The coolant concentration must not be reduced by adding plain
water, even in the summer or in warm climates. The concentration
of the anti-freeze additive must always be at least 40%.
Countries with cold climate
If greater anti-freeze protection is required in very cold climates, the
proportion of the anti-freeze additive G12++ can be increased. A
concentration of 60% offers protection down to about - 40 °C. The
concentration of the anti-freeze additive must not be more than
60%, otherwise this would reduce the anti-freeze protection. In addi-
tion, the cooling effect will be adversely affected.
Vehicles for export to countries with a cold climate (such as Sweden,
Norway and Finland) are supplied with antifreeze protection down
to about -35 °C. The concentration of the antifreeze additive for
these countries should always be at least 50%.
Caution
•
It is advisable to have the cooling system checked before the
winter season to make sure that the antifreeze concentration is
adequate for the conditions to be expected. This applies particularly
if you intend to take the car into a colder climate zone. If necessary,
have the anti-freeze concentration increased to 50 - 60% as required.
•
Use only anti-freeze additive G12++, an additive meeting the
specification “TL 774 G”. Other additives may give considerably
inferior corrosion protection. The resulting corrosion in the cooling
system can lead to a loss of coolant, causing serious damage to the
engine.
Aa
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Checking and topping up fluids261
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
The coolant additive G12++ can be mixed only with additives
G12+ and G12.
Checking coolant level
The coolant level can be checked at a glance.– Switch off the ignition.
– Read off coolant level on radiator expansion tank
⇒fig. 257. When the engine is cold it should be between
the “MIN” and “MAX” marks. When the engine is hot it
may be slightly above the “MAX” mark.The coolant level should be checked with the engine switched off.
The coolant level is monitored by a warning lamp in the instrument
cluster ⇒page 33. However, we recommend that it should be
checked occasionally.
Coolant losses
Any loss of coolant normally indicates a leak in the cooling system.
In this case the cooling system should be inspected by a qualified
workshop without delay. It is not sufficient merely to top up the
coolant.If there are no leaks in the system, a loss of coolant can only occur
if the coolant boils and is forced out of the system as a result of
overheating.
Caution
Radiator sealants must not be added to the coolant. Such additives
could seriously impair the function of the cooling system.Topping up the coolant
Be careful when topping up coolant.– Switch off the engine.
– Wait for the engine to cool down.
– Cover the cap on the expansion tank ⇒fig. 257 with a
cloth, and carefully unscrew the cap anti-clockwise
⇒.
– Add coolant.
– Screw the cap on again tightly.Make sure that the coolant meets the required specifications
⇒page 260, “Coolant”. Do not use a different type of additive if anti-
freeze additive G12++, G12+ or G12 is not available. In this case use
only water and bring the coolant concentration back up to the
correct level as soon as possible by putting in the specified additive.
Always top up with fresh, unused coolant.
Do not fill above the “MAX” mark. Excess coolant is forced out of the
system through the valve in the filler cap when the engine gets hot.
If a lot of coolant has been lost, wait for the engine to cool down
before putting in cold coolant. Failure to do so could result in
serious engine damage.
Fig. 257 Engine
compartment: Mark-
ings on radiator expan-
sion tank
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