2003 MERCEDES-BENZ SLK320 Owner's Manual

177 Operation
Engine compartment

Add coolant as required.

Turn the cap back, past the first detent
position, as far as it will go.
More information on coolant can be found
in the “Technical data” section
(
page 273).
SLK 320, SLK 32 AMG1Coolant expansion tank
2Marker in the filler neck
Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.

Continue turning the cap to the left and
remove it.The coolant level is correct if the level


for cold coolant: the level must
reach marker2 in the filler neck of
the expansion tank.


for warm coolant: is approx. 0.6 in
(1.5 cm) higher

Add coolant as required.

Replace and tighten cap.
More information on coolant can be found
in the “Technical data” section
(
page 273).
iThe drain plugs for the cooling system
are located on the right side of the en-
gine block and at the bottom of the ra-
diator.
iThe drain plugs for the cooling system
are located on the right side of the en-
gine block and at the bottom of the ra-
diator.

178 OperationEngine compartmentBattery
Your vehicle’s battery is located in the en-
gine compartment.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle mostly for short dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
Observe all safety instructions
and precautions when handling
automotive batteries.Risk of explosionKeep flames or sparks away
from battery. Do not smoke.Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
Wear eye protection.Keep children away.Follow the instructions in this
Operator's Manual.

179 Operation
Engine compartment
Windshield washer system and headlamp cleaning system*
Fluid for the windshield washer system and
the headlamp cleaning system* is supplied
from the windshield washer reservoir. It
has a capacity of approx. 7.4 US qt (7 l).
During all seasons, add MB Windshield
Washer Concentrate “S” to water. Premix
the windshield washer fluid in a suitable
container.
Refill the reservoir with MB Windshield
Washer Concentrate and water (or
commercially available premixed wind-
shield washer solvent / antifreeze, de-
pending on ambient temperatures).
Always use washer solvent/antifreeze
where temperatures may fall below
freezing. Failure to do so could result in
damage to the washer system/reser-
voir.More information can be found in the
“Technical data” section (
page 275).1Washer fluid reservoir
Warning!
G
Washer solvent / antifreeze is highly flam-
mable. Do not spill washer
solvent / antifreeze on hot engine parts, be-
cause it may ignite. You could be seriously
burned.iThe windshield washer system on this
vehicle is heated, so a fluid mixture pro-
duced for temperatures of
approximately 14°F (-10°C) should be
sufficient.
!Only use washer fluid which is suitable
for plastic lenses. Improper washer flu-
id can damage the plastic lenses of the
headlamps.

180 OperationTires and wheels
Tires and wheelsSee your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation. They can also offer ad-
vice concerning tire service and purchase.
Retread tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
See your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation.
Important guidelines

Use only sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage.


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires are no longer guar-
anteed.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, use only genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.

181 Operation
Tires and wheels
Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style


Tire pressure


Distance driven
Direction of rotation
Unidirectional tires offer added advantag-
es, such as better aquaplaning perfor-
mance. To benefit, however, you must
ensure that the tires rotate in the direction
specified.
An arrow on the sidewall indicates the in-
tended direction of tire rotation.Checking tire inflation pressureCorrect the tire pressure only when tires
are cold.
Regularly check your tire pressure at inter-
vals of no more than 14 days.
If the tires are warm, you should only cor-
rect the tire pressure if it is too low for cur-
rent operating conditions.
A table on the fuel filler flap lists the spec-
ified tire inflation pressures for warm and
cold tires as well as for various operating
conditions.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.
Warning!
G
If the tire pressure repeatedly drops:

Check the tires for punctures from for-
eign objects.


Check to see whether air is leaking from
the valves or from around the rim.
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed in the fuel filler flap.

182 OperationTires and wheelsTire pressure changes by approximately
1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind
when checking tire pressure where the
temperature is different from the outside
temperature.
The tire temperature and with it the tire
pressure is increased also while driving,
depending on the driving speed and the
tire load.Check the spare tire periodically for condi-
tion and inflation. Spare tires will age and
b e c o m e w o r n o v e r t i m e e v e n i f n e v e r u s e d ,
and thus should be inspected and replaced
when necessary.
Rotating wheels
The wheels can be rotated every 3000 to
6000 miles (5 000 to 10000 km), or soon-
er if necessary, according to the degree of
tire wear. The same direction of tire rota-
tion must be retained.Rotate the wheels before the characteris-
tic tire wear pattern becomes visible
(shoulder wear on front wheels and tread
center wear on rear wheels).
Thoroughly clean the inner side of the
wheels after each rotation. Check and en-
sure proper tire inflation pressure.
Warning!
G
Follow recommended inflation pressure.
Do not overinflate tires. Overinflated tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.Warning!
G
Rotate front and rear wheels only if they are
of the same size.
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
80 ft.lb. (110 Nm).
Use only genuine Mercedes-Benz wheel
bolts specified for your vehicle's rims.

183 Operation
Winter driving
Winter driving
Before the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp*
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent / antifreeze which is formulated
for below freezing temperatures
(page 275).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
that the engine can be started, even at
low ambient temperatures.


Tire change. We recommend M+S
rated radial-ply tires on all four wheels
for the winter season.
Winter tires
Always use winter tires at temperatures
below 39°F (4°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS and ESP in winter
operation.
For safe handling, ensure that all mounted
winter tires are of the same make and have
the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-
tices are available from your tire dealer or
from any authorized Mercedes-Benz
Center.Warning!
G
Winter tires with a tread depth under 0.16 in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Center.

184 OperationWinter drivingBlock heater (Canada only)
The engine is equipped with a block
heater.
The electrical cable may be installed at
your authorized Mercedes-Benz Center.Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.Please observe the following guidelines
when using snow chains:


Use of snow chains is not permissible
with all wheel/tire combinations.


Chains should only be used on the rear
wheels. Follow the manufacturer's
mounting instructions.


Use only snow chains that are ap-
proved by Mercedes-Benz. Your autho-
rized Mercedes-Benz Center will be
glad to advise you on this subject.
iWhen driving with snow chains, you
may wish to deactivate the ESP
(page 70) before setting the vehicle
in motion. This will improve the vehi-
cle’s traction.
!Use of snow chains is not permissible
with tire size 225 / 45 R17 91 H M+S,
with the collapsible tire, with the tire
size 225 / 50 R16 92 V, with the tire
size 225 / 50 R16 92 W and the tire
size 245 / 40 R17 91 Y (Sport Pack-
age*).