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 294 of 464
294 OperationEngine compartmentThe coolant expansion tank is located on
the passenger side of the engine compart-
ment.SLK 350 (example)1Coolant expansion tank
2Cap
3Marking bar in the expansion tank
Using a rag, turn cap2 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning cap2 counterclock-
wise and remove it.
The coolant level is correct if the level
for cold coolant: reaches marking
bar3 in expansion tank1
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap2.
For more information on coolant, see
“Coolants” (
page 426).
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 the Maintenance Booklet
for battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more frequent-
ly.
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.
Page 327 of 464
327 Operation
Winter driving
Winter driving
Before the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:
Checking anticorrosion and antifreeze
concentration.
Adding of cleaning concentrate to the
water of the windshield and headlamp
cleaning* system. Add
MB Concentrate “S” to a pre-mixed
windshield washer solvent/antifreeze
which is formulated for temperatures
below freezing point (
page 429).
Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure 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 1/6in (4.0 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. Using 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 mounted to 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.
!When scraping ice or snow from the
rear window, be careful not to damage
the sealing strip or apertures along the
side of the window.
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.
Page 343 of 464
343 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
;
3
(USA only)
(Canada only)
The red brake warning
lamp comes on while driv-
ing and you hear a warning
sound.
You are driving with the parking brake
set.
Release the parking brake
(page 49).
The red brake warning
lamp comes on while driv-
ing.
There is insufficient brake fluid in the
reservoir.
Risk of accident! Carefully stop the
vehicle and notify an authorized
Mercedes-Benz Center. Do not add
brake fluid! This will not solve the
problem.
Warning!
G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on. Do not add
brake fluid before checking the brake
system. Overfilling the brake fluid reservoir
can result in spilling brake fluid on hot
engine parts and the brake fluid catching
fire. You can be seriously burned.
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks.
Page 344 of 464
344 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
?
±
(USA only)
(Canada only)
The yellow engine
malfunction indicator
lamp comes on while
driving.
There is a malfunction in:
the fuel management system
the ignition system
the emission control system
systems which affect emissions
Such malfunctions may result in ex-
cessive emissions values and may
switch the engine to its limp-home
(emergency operation) mode.
Have the vehicle checked as soon as possible
by an authorized Mercedes-Benz Center.
An on-board diagnostic connector is used by
the service station to link the vehicle to the
shop diagnostics system. It allows the accu-
rate identification of system malfunctions
through the readout of diagnostic trouble
codes. It is located in the front left area of the
footwell near the hood release.
Your fuel tank is empty.
After refueling start, turn off and restart the
engine three or four times in succession.
The limp-home mode is canceled. You do not
need to have your vehicle checked.
Additionally you see
the message
Check
gas cap
See Operator’s
Manual
in the multi-
function display.
A loss of pressure has been detect-
ed in the fuel system. The fuel cap
may not be closed properly or the
fuel system may be leaking.
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.
Page 346 of 464
346 Practical hintsWhat to do if …4
The yellow fuel reserve warning lamp
flashes after starting the engine.
The fuel cap is not closed properly.
Close the fuel cap.
<
The red seat belt telltale comes on
after starting the engine and with all
doors closed.
The seat belt telltale reminds you
and your passenger to fasten your
seat belts.
Fasten your seat belts.
For more information, see “Seat belts”
(page 69).
1
The red SRS indicator lamp comes
on while driving.
There is a malfunction in the re-
straint systems. The air bags or
emergency tensioning devices
(ETDs) could deploy unexpectedly or
fail to deploy in an accident.
Drive with added caution to the nearest au-
thorized Mercedes-Benz Center.
Problem
Possible cause
Suggested solution
Warning!
G
In the event that a malfunction of the SRS is
indicated as outlined above, the SRS may
not be operational. For your safety, we
strongly recommend that you visit an
authorized Mercedes-Benz Center immedi-
ately to have the system checked;
otherwise the SRS may not be activated
when needed in an accident, which could re-
sult in serious or fatal injury, or it might de-
ploy unexpectedly and unnecessarily which
could also result in an accident and/or
injury to you or to others.
Page 356 of 464
356 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
USA only:;Canada only:!
Release
parking brake
You are driving with the parking
brake set.
Release parking brake (
page 49).
2
Brake wear
Visit workshop
The brake pads have reached their
wear limit.
Have the brake pads replaced as soon as
possible.
3
Brake fluid
Visit workshop
There is insufficient brake fluid in
the reservoir.
Risk of accident! Stop the vehicle and notify
an authorized Mercedes-Benz Center. Do
not add brake fluid! This will not solve the
problem.
Warning!
G
Driving with this message displayed can re-
sult in an accident. Have your brake system
checked immediately. Do not add brake flu-
id before checking the brake system.
Overfilling the brake fluid reservoir can re-
sult in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You
can be seriously burned.
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks.
!Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Maintenance
Booklet.