Page 288 of 464

288 OperationEngine compartment
Closing
Let the hood drop from a height of
approximately 1 ft (30 cm).
The hood will lock audibly.
Check to 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 display in the multifunction display
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 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
(ignition coils, spark plug sockets, diagnos-
tic 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 may
cause damage not covered by the
Mercedes-Benz Limited Warranty.
More information on this subject is
available at any authorized
Mercedes-Benz Center.
Page 291 of 464

291 Operation
Engine compartment
Checking engine oil level with the oil
dipstick, SLK 350
When checking the oil level
the vehicle must be parked on level
ground.
with the engine at operating tempera-
ture, the vehicle must have been sta-
tionary for at least five minutes with
the engine turned off.
with the engine not at operating tem-
perature, the vehicle must have been
stationary for at least 30 minutes with
the engine turned off.1Oil dipstick
2Upper (max) mark
3Lower (min) mark
To check the engine oil level with the oil
dipstick, do the following:
Open the hood (
page 287).
Pull out oil dipstick1.
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.
The oil level is correct when it is be-
tween the lower (min) mark3 and
upper (max) mark2 of oil dipstick1.
If necessary, add engine oil.
For adding engine oil, see “Adding en-
gine oil” (
page 292).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 422).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(page 348).iThe filling quantity between the upper
and lower marks on the oil dipstick is
approximately 2.1 US qt. (2.0 l).
Page 293 of 464

293 Operation
Engine compartment
Transmission fluid level*
Vehicles with automatic transmission*:
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 level
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.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 coolant temperature is
above 158°F (70°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
glycol which may burn if it comes into
contact with hot engine parts.
Page 358 of 464

358 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The coolant is too hot.
Stop the vehicle and turn off the engine.
Only start the engine again after the mes-
sage disappears. You could otherwise dam-
age the engine.
/
Coolant
Check level
The coolant level is too low.
Add coolant (
page 293).
If you have to add coolant frequently, have
the cooling system checked by an autho-
rized Mercedes-Benz Center.
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have
leaked into the engine compartment to
catch fire. You could be seriously burned.
Steam from an overheated engine can cause
serious burns and can occur just by opening
the hood. Stay away from the engine if you
see or hear steam coming from it. Turn off
the engine, get out of the vehicle and do not
stand near the vehicle until the engine has
cooled down.
The engine should not be operated with the
coolant temperature above 248°F (120°C).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty.Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
this message and symbol displayed
may cause serious engine damage not
covered by the Mercedes-Benz Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat, causing major en-
gine damage.
Page 362 of 464
362 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
A
Fuel reserve
The fuel level has dropped below
the reserve mark.
Refuel at the next gas station (
page 284).
Check gas cap
See Operator’s Manual
The fuel cap may not be closed
properly.
Check the fuel cap (
page 284).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an autho-
rized Mercedes-Benz Center.
K
Lock retractable roof
The retractable hardtop is not
locked properly.
Push the retractable hardtop switch forward
or rearward until the retractable hardtop is
completely closed or open (
page 237).
Retractable roof
Visit workshop
The retractable hardtop is
malfunctioning.
Have the retractable hardtop checked by an
authorized Mercedes-Benz Center.
O
Close hood
You are driving with the hood open.
Close the hood (
page 287).
F
Replace key
The SmartKey is malfunctioning.
Visit an authorized Mercedes-Benz Center.
Page 382 of 464
382 Practical hintsReplacing bulbsNotes on bulb replacement
Only use 12-volt bulbs of the same type
and with the specified watt rating.
Switch lights off before changing a bulb
to prevent short circuits.
Always use a clean lint-free cloth when
handling bulbs.
Your hands should be dry and free of oil
and grease.
If the newly installed bulb does not
come on, visit an authorized
Mercedes-Benz Center.Have the LEDs and bulbs for the following
lamps replaced by an authorized
Mercedes-Benz Center:
Additional turn signal lamps in the
exterior rear view mirrors
Bi-Xenon* lamps
Front fog lamps
High mounted brake lamp
Brake lamps
Front and rear side marker lamps
Parking/standing lamps in the tail
lamp assemblies
Replacing bulbs for front lamps
Before you start to replace a bulb for a
front lamp, do the following first:
Turn the exterior lamp switch to
positionM (
page 106).
Open the hood (
page 287) (except
for side marker lamps).
iHave the headlamp adjustment
checked regularly.
Page 387 of 464

387 Practical hints
Replacing wiper blades
Installing wiper blades
1Installing
2Tabs
3Attachment
4Guide tab
5Cover
Slide the wiper blade into
attachment3 in direction of
arrow1.
Make sure guide tab4 will be placed
under cover5 when fully inserting the
wiper blade into attachment3.
Let tabs2 latch in into both recesses
of attachment3.
Check if the wiper blade is securely
fastened.
Fold the wiper arm backward to rest on
the windshield.
Make sure you hold on to the wiper arm
when folding it back.
!Never open the hood when the wiper
arms are folded forward.
Hold on to the wiper when folding the
wiper arm back. If released, the force
of the impact from the tensioning
spring could crack the windshield.
Do not allow the wiper arms to contact
the windshield glass without a wiper
blade inserted.
Make sure the wiper blades are proper-
ly installed. Improperly installed wiper
blades may cause windshield damage.
For your convenience, you should have
this work carried out by an authorized
Mercedes-Benz Center.
Page 397 of 464

397 Practical hints
Battery
Disconnecting the battery
1Water tray
2Lock
Depress parking brake firmly or move
g e a r s e l ec t o r le v e r * t o p o s it io nP (man-
ual transmission to Neutral).
Switch off all electrical consumers.
Remove SmartKey from starter switch.
Open the hood (
page 287).
Turn locks2 one quarter turn.
Remove water tray1.
Read and observe safety instructions
and precautions (
page 396).
Disconnect the battery negative lead.
Remove the cover from the positive
terminal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw on the swivel bar.
Remove the swivel bar.
Take out the battery.
Charging and reinstalling battery
Warning!
G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch
automatic transmission*: the gear se-
lector lever will remain locked in
positionP
Warning!
G
Never charge a battery while still installed in
the vehicle unless the accessory battery
charge unit approved by Mercedes-Benz is
being used. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
An accessory battery charge unit specially
adapted for Mercedes-Benz vehicles and
tested and approved by Mercedes-Benz is
available, permitting the charging of the bat-
tery in its installed position. Contact an
authorized Mercedes-Benz Center for infor-
mation and availability. Charge battery in
accordance with the separate instructions
for the accessory battery charger.