Inspecting and replenishing
220
Inspecting the coolant levelThe coolant expansion bottle is located in the engine compartment on the right.
– Switch the engine off.
– Open the bonnet page 216, “Working in the engine compartment”.
– Check the level of coolant in the coolant expansion bottle fig. 184 . The coolant
level when the engine is cold must lie between the (MIN) and (MAX) mark-
ings. The level may also rise slightly ab ove the (MAX) marking when the engine
is warm.
If the coolant level in the reservoir is too lo w, this is indicated by the warning light in
the instrument cluster
page 32. We nevertheless recommend inspecting the
coolant level directly at the reservoir from time to time.
Loss of coolant
A loss of coolant is first and foremost an indication of a leak in the system. You should
not merely top up the coolant in the reservoir. It is also important to have the cooling
system inspected without delay by a specialist garage.
Losses can only occur through the pressure relief in the cap of the coolant expansion
bottle which is completely free of leaks if the coolant boils as a result of overheating
and is forced out of the cooling system.
WARNING
Read and observe the warning notes page 216, “Working in the engine
compartment” before working in the engine compartment.
Caution
One should contact a specialist garage as s oon as possible if the source of overheating
itself cannot be determined and removed, since there may be grave damage to the
engine.Replenishing the coolant– Switch the engine off.
– Allow the engine to cool down.
– Place a cloth over the cap of the coolant expansion reservoir fig. 184 and
unscrew the cap carefully by turning it to the left .
–Top up the coolant.
– Screw the cap tight until it is heard to lock.
The coolant which you use for replenishing the system, must comply with one specific
specification page 219, “Coolant”. Do not use an al ternative additive if the coolant
additive G13 is not available in exceptional cases. Just top up the system with water
and as soon as possible arrange adjustment to correct the mixing ratio of water and
coolant additive again by a specialist garage.
Only use fresh coolant for topping up the system.
Do not fill up over the “MAX” marking! Excess coolant which is heated up is forced out
of the cooling system through the pressure relief valve in the cap of the coolant
compensation bottle.
Wait until the engine has cooled down for a system which has suffered a major loss of
coolant before pouring in coolant. This is necessary to avoid engine damage.
WARNING
The cooling system is pressurized! Do not open the cap of the coolant
expansion bottle if the engine is still hot - risk of scalding!
The coolant additive and thus all of the coolant is harmful to your health.
Avoid contact with the coolant. Coolant vapours are also harmful to the health.
It is important, therefore, to always safely store any coolant additive in its orig-
inal container out of the reach of children - risk of poisoning!
Fig. 184 Engine compartment: Coolant
expansion bottle
Ab
Aa
Aa
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Wheels and Tyres
228
Wheels and TyresWheelsGeneral information
New tyres do not offer optimal grip at first and should therefore be run in for about
500 km at a moderate speed and an appropri ately cautious style of driving. You will
also profit from longer tyre life.
The tread depth of new tyres may differ be cause of design features and the config-
uration of the tread (depending on the type of tyre and the manufacturer).
Drive over curbs on the side of the road and other such obstacles slowly and,
where possible, at a right angle in order to avoid damage to tyres and wheel trims.
Inspect your tyres from time to time for damage (punctures, cuts, splits and
bulges). Remove foreign bodies from the tyre profile.
Damage to tyres and wheels is frequently not visible. Unusual vibrations or pulling
of the vehicle to one side coul d be a sign of tyre damage. Please reduce your speed
immediately and stop if you su spect that a wheel is damaged. Inspect the tyres for
signs of damage (bulges, splits, etc.). If no visible damage is present, please drive at an
appropriately slow speed and carefully to the nearest specialist garage in order to have
your vehicle inspected.
Also protect your tyres from contact with oil, grease and fuel.
Immediately replace any dust caps of the valves which have got lost.
Mark wheels before removing them so that their previous direction of running can
be maintained when mounted them again.
Always store wheels or tyres which been removed in a cool, dry and, where
possible, dark place. Tyres which are not fixed to a wheel trim should be stored upright.
Unidirectional tyres*
The direction of rotation of the tyres is mark ed by arrows on the wall of the tyre. This
indicates the direction of rotation of the tyre, and it is essential that the tyres are fitted
on to run in this direction. Only then are the tyres able to provide the optimal proper-
ties in terms of grip, low nois e, wear-and-tear and aquaplaning.
Further information concerning th e use of unidirectional tyres page 232.
WARNING
New tyres during the first 500 km do not offer optimal grip and should
therefore be run appropriately - risk of accident!
Never drive with damaged tyres - risk of accident!Note
Please observe the various differing legal requirements regarding tyres.Ty re l i feThe life of your tyres very much depends on the following points:
Tyre pressure
The working life of tyres will be shortened considerably if the tyres are insufficiently or
over-inflated and this will have an adverse effect on the handling of your vehicle.
Correctly inflated tyres are of particular importance when travelling at high speeds. It
is therefore good to check the pressure at least once a month and also before setting
off on a long trip. Please do not forget the spare wheel when checking the tyres.
The tyre inflation pressures for summer tyres are indicated on the inside of the fuel
filler flap fig. 189 . The inflation pressures for winter tyres are 20 kPa (0.2 bar) higher
than those for summer tyres page 232.
Fig. 189 An opened fuel filler flap with a
tyre size and tyre inflation pressure table
s3fg.2.book Page 228 Friday, April 30, 2010 12:17 PM
Breakdown assistance
238
– Take off the wheel.
– Fit on the spare wheel and ti ghten the wheel bolts slightly.
–Lower the car.
– Tighten the wheel bolts firmly, alternately and diagonally using the wheel wrench (crosswise) and last the safety wheel bolt* page 239.
– Mount the full wheel trim/wheel trim cap or the caps.
Note
All bolts must be clean and must turn easily.
You must never grease or oil the wheel bolts!
When fitting on unidirectional tyres, ensu re that the tyres rotate in the correct
direction page 228.
Subsequent stepsAfter changing the wheel, you must perform the following steps.
– Stow and attach the replaced wheel in the spare wheel well using a special screw
page 236, fig. 195 .
– Stow the vehicle tool kit in the space provided.
– Check the tyre pressure on the spare wheel just mounted as soon as possible.
– Have the tightening torque of the wheel bolts checked with a torque wrench as
soon as possible. Steel and light alloy wh eels must be tightened to a tightening
torque of 120 Nm .
– Change the damaged wheel or consult a specialist garage about possibilities for getting repairs done.
WARNING
It is necessary to observe the guidelines given on page 230 if the vehicle is
subsequently fitted with tyres which are different to those it was fitted with at
the works.
Note
If you find, when changing the wheel, that the wheel bolts are corroded and diffi-
cult to turn, the bolts must be replaced before checking the tightening torque.
Drive cautiously and only at a moderate speed to a workshop where the tightening
torque can be checked.
Full wheel trim*Pulling off– Hook the clamp found in the vehicle tool ki t into the reinforced edge of the full
wheel trim.
– Push the wheel key through the clamp, support the wheel key at the tyre and pull off the wheel trim.Installing– First press the full wheel trim onto the wheel at the valve opening provided. Then
press the full wheel trim into the wheel in such a way that its entire circumference
locks correctly in place.
Caution
Use the pressure of your hand, do not knock on the full wheel trim! Heavy knocks
mainly on the points where the full wheel trim has not been inserted into the wheel,
can result in damage to the guide and centering elements of the full wheel trim.
Check for yourself that the safety wheel bolt is located in the hole in the area of the
valve before fitting the full wheel trim onto a steel wheel which is attached with a safety
wheel bolt page 240, “Securing wheels against being stolen*”.
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