175 Operation
Engine compartment
Closing
Let the hood drop from a height of ap-
proximately 1ft (30cm).
The hood will lock audibly.
Make sure 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
higher engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
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 down. If neces-
sary, 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.
iDo not use any special lubricant addi-
tives, as these may damage the drive
assemblies. Using special additives not
approved by Mercedes-Benz will
restrict your warranty entitlement.
More information on this subject is
available at any authorized Mer-
cedes-Benz Center.
176 OperationEngine compartmentChecking engine oil level via display
(SLK 320, SLK 32 AMG only)
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
To check the engine oil level via the display
in the speedometer, do the following:
Turn the key in the steering lock to
position2.
1Button
Wait until the symbols: andI
appear in the speedometer display.
Within one second press button1
twice.
One of the following messages will
subsequently appear in the display:
OKThe oil level is correct. Engine oil
does not to be added.
-1.0 Q(Canada:
-1.0 L
)
Add 1.0 quart (Canada:
1.0 liter) of engine oil.
-1.5 Q
(Canada:
-1.5 L
)
Add 1.5 quarts (Canada:
1.5 liters) of engine oil.
-2.0 Q(Canada:
-2.0 L
)
Add 2.0 quarts (Canada:
2.0 liters) of engine oil.For adding engine oil see (
page 179).
More information on engine oil can be
found in the “Technical data” section
(
page 277) and (
page 279).
Other display messages
If there is excess engine oil with the engine
at normal operating temperature, a signal
sounds and the following message will
blink in the display:
HIThe oil level is too high.
Have excess oil siphoned or drained
off. Contact your authorized Mer-
cedes-Benz Center.!If the message
-2.0 Q
(Canada:
-2.0 L
) blinks and a signal
sounds, add oil according to amount
displayed.
177 Operation
Engine compartment
TheI symbol flashes in the
speedometer display if a proper oil level
check cannot be performed.
If engine is at normal operating
temperature, wait five minutes before
repeating check procedure.
If engine is not yet at normal operating
temperature, wait 30 minutes before
repeating check procedure.See the “Practical hints” section
(
page 199) if the low engine oil level
warning lamp in the instrument cluster
comes on.
Checking engine oil level with the oil
dipstick
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
!Excess 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.
iPerform the engine oil level check with
the dipstick if it cannot be completed
via the speedometer display
(page 177).
In this case we recommend that you
have the system checked at a
Mercedes-Benz Center.
iIf the: andI symbols are
continuously illuminated after pressing
button1 (
page 176) twice, and if
there is no change in the speedometer
display or the low engine oil level
warning lamp comes on, a malfunction
has occurred to the system.
Perform the engine oil level check with
the dipstick (page 177).
Visually check for oil leaks. If no obvi-
ous oil leaks are noted, drive to the
nearest authorized Mercedes-Benz
Center to have the system checked.
iThe engine oil level can be checked by
either the oil dipstick or via the
speedometer display (SLK 320,
SLK 32 AMG only) in the instrument
cluster (
page 176). The amount of
engine oil needed is shown more
precisely in the speedometer display.
178 OperationEngine compartmentTo check the engine oil level with the oil
dipstick, do the following:
Open the hood (
page 174).
Pull out oil dipstick1 (
page 179)
Wipe oil dipstick1 clean.
Fully insert oil dipstick1 into the
dipstick guide tube.
Pull out oil dipstick1 again after
approximately three seconds to obtain
accurate reading.
Oil dipstickThe oil level is correct when it is between
the lower (min) and upper (max) mark of
the oil dipstick.
If necessary, add engine oil.
For adding engine oil see (
page 179).
More information on engine oil can be
found in the “Technical data” section
(
page 277) and (
page 279).
See the “Practical hints” section
(
page 199) if the low engine oil level
warning lamp in the instrument cluster
comes on.
iThe filling quantity between the upper
and lower marks on the oil dipstick is
approximately 2.1 US qt. (2.0 l).
179 Operation
Engine compartment
Adding engine oil
SLK 230 Kompressor1Oil dipstick
2Filler cap
Unscrew filler cap2 from filler neck.
Add engine oil as required. 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 filler cap2 back on filler neck.
SLK 320, SLK 32 AMG1Oil dipstick
2Filler cap
Unscrew filler cap2 from filler neck.
Add engine oil as required. Be careful
not to overfill with oil.
!Only use approved engine oils. For a
listing of approved engine oils, refer to
the Factory Approved Service Products
pamphlet in your vehicle literature port-
folio.
In addition, check the oil filler cap for
important information pertaining to the
engine oil needing to meet a specific
Mercedes-Benz specification (e.g. MB
229.5). If such information is printed
on the oil filler cap, only use an engine
oil from the list of approved engine oils
in the Factory Approved Service Prod-
ucts pamphlet that meets the specifi-
cation indicated on the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.
!Excess 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.
180 OperationEngine compartmentBe careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap2 back on filler neck.
More information on engine oil can be
found in the “Technical data” section
(
page 277) and (
page 279).
Transmission 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.
!Excess 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.
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.
183 Operation
Engine compartment
Battery
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. Refer to Service Booklet for bat-
tery maintenance intervals.
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.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
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.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.
188 OperationWinter driving
Winter drivingBefore 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 temperatures below freezing point
(page 277).
Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
the engine can be started, even at low
ambient temperatures.
Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately 1/6 in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°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, make sure 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 at your tire dealer or any
authorized Mercedes-Benz Center.Warning!
G
Winter tires with a tread depth under
1/6 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.