engine MERCEDES-BENZ SLK CLASS 2003 Workshop Manual

172 OperationEngine compartment
Closing
Let the hood drop from a height of ap-
proximately 1ft (30cm).
The hood will lock audibly.

Check to make sure that the hood is
fully closed.
If you can raise the hood at a point
above the headlamps, then it is not
properly closed. Open it again and let it
drop with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when

the vehicle is new


the vehicle is driven frequently at high-
er engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Checking engine oil level
When checking the oil level the vehicle
must


be parked on level ground


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from vehicle and do not open the hood
until the engine has cooled. If necessary,
call the fire department.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition coils, spark plug sockets, diagnostic
socket) of the ignition system

with the engine running


while starting the engine


if ignition is “on” and the engine is
turned manually
Warning!
G
Be careful that you do not close the hood on
anyone.

173 Operation
Engine compartment
You can check the engine oil level with
the oil dipstick
Open the hood (
page 171).

Pull out oil dipstick1 (
page 175) and
wipe the tip clean.

Reinsert the oil dipstick into the dip-
stick guide tube as far as it will go.
1Oil dipstick

Pull out the oil dipstick again after
approximately 3 seconds.
The oil level is acceptable when it
leaves a line between the upper and
lower marks of the dipstick.
For adding oil (
page 175).
See “Practical hints” (
page 200) if the
low engine oil level warning lamp in the in-
strument cluster lights up.You can check the engine oil level on the
odometer display (SLK 320 and
SLK 32 AMG only)

Turn the key in the steering lock to
position2.
1Knob

Wait until the symbols
:
and
I

appear in the odometer display indica-
tor.
iFill quantity between upper and lower
dipstick marking level is approximately
2.1 US qt (2.0 l).


174 OperationEngine compartment
Within 1 second press knob1 on the
instrument cluster twice.
One of the following messages will sub-
sequently appear in the indicator:

OK


-1.0 Q
(Canada:
-1.0 L
)


-1.5 Q
(Canada:
-1.5 L
)


-2.0 Q
(Canada:
-2.0 L
)
For adding oil (
page 175).If there is excessive engine oil with the en-
gine at normal operating temperature, a
signal sounds and the following message
will blink in the odometer display:
HI
Have excess oil siphoned.
If theI
symbol flashes in the odometer
display field, a proper oil level check can-
not be performed.

Wait 5 minutes before repeating check
procedure.
Perform the oil level check with the dip-
stick (
page 173) if it cannot be complet-
ed via the odometer display field. In this
case we recommend that you that you
have the system checked at a
Mercedes-Benz Center.See “Practical hints” (
page 200) if the
low engine oil level warning lamp in the in-
strument cluster lights up.
!If the message
-2.0 Q

(Canada:
-2.0 L
) blinks and a signal
sounds, add oil according to amount
displayed.
iIf the
:
and
I
symbols are con-
tinuously illuminated after pressing the
left knob on the instrument cluster
twice, and if there is no change in the
odometer display field or the low en-
gine oil level warning lamp comes on, a
malfunction has occurred to the sys-
tem.
Perform the engine oil level check with
the dipstick (
page 173).
If no oil leaks are noted, drive to the
nearest Mercedes-Benz Center to have
the system checked.

175 Operation
Engine compartment
Adding engine oilSLK 230 Kompressor1Oil dipstick
2Oil filler cap
Unscrew oil filler cap2 from the filler
neck.
Be careful not to overfill with oil.
Be careful not to spill any oil when
adding.
Avoid environmental damage caused
by oil entering the ground or water.

Screw oil filler cap2 back onto the filler
neck.
SLK 320, SLK 32 AMG1Oil dipstick
2Oil filler cap
Unscrew oil filler cap2 from the filler
neck.Be careful not to overfill with oil.
Be careful not to spill any oil when
adding.
Avoid environmental damage caused
by oil entering the ground or water.

Screw oil filler cap2 back onto the filler
neck.
More information on engine oil can be
found in the “Technical data” section
(
page 271).
!Excessive oil must be siphoned or
drained off. It could cause damage to
the engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
!Excessive oil must be siphoned or
drained off. It could cause damage to
the engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.

176 OperationEngine compartmentTransmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Center
check the transmission.Coolant
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
SLK 230 Kompressor1Coolant expansion tank
2Float in the filler neck
Using a rag, turn the cap to the left to
the first detent position. Allow any ex-
cess pressure to escape.

Continue turning the cap to the left and
remove it.
The coolant level is correct if float2
can be seen at the top through the filler
neck.
Warning!
G
In order to avoid any possibly serious burns:

Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.


Do not remove pressure cap on coolant
reservoir if engine temperature is above
194°F (90°C). Allow engine to cool
down before removing cap. The coolant
reservoir contains hot fluid and is under
pressure.


Using a rag, slowly open the cap approx-
imately ½ turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.


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.

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*).