engine overheat MERCEDES-BENZ SLK350 2006 R171 Owner's Manual

129 Controls in detail
Control system
Displaying digital speedometer or
outside temperature
Press buttonjork repeatedly
until you see the digital speedometer.
The current vehicle speed is shown in
the multifunction display.
AUDIO menu
The functions in the
AUDIO
menu operate
the audio equipment which you currently
have turned on.
If no audio equipment is currently switched
on, the message
AUDIO off
is shown in the
multifunction display.
The following functions are available:
Warning!
G


Driving when your engine is overheated
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 com-
ing from it.
Turn off the engine, get out of the car and do
not stand near the vehicle until the engine
has cooled down.
iYou can select either the display of the
digital speedometer or the outside
temperature indicator (
page 138).
Function
Page
Selecting radio station
130
Selecting satellite radio
station* (USA only)
130
Operating the CD player
131

295 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream will cool down
the brakes faster.High-performance brake system
(SLK 55 AMG only)
The high-performance brake system is de-
signed to operate under the extremely high
operating demands required to accommo-
date the performance capabilities of the
vehicle. The brakes may produce a squeak-
ing-type noise depending on the


vehicle speed


brake force applied


ambient conditions, e.g. temperature
and humidity
As with any brake system, the wear of indi-
vidual brake system components such as
brake pads or discs strongly depends on
your driving style and the conditions under
which you operate the vehicle. Thus, a driv-
ing style calling for high demand braking
will cause your vehicle’s brakes to wear
more quickly.
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.!When driving down long and steep
grades, relieve the load on the brakes
by shifting into a lower gear to use the
engine’s braking power. This helps pre-
vent overheating of the brakes and re-
duces brake pad wear.
Warning!
G
New vehicle brake pads and discs, and
replacement brake pads and discs may take
several hundred miles of driving until they
provide optimum braking efficiency. Until
that time, you may need to use increased
brake pedal pressure while braking. Please
be aware of this and adjust your driving and
braking accordingly during this break-in
period.
Excessive high demand braking will cause
correspondingly high brake wear. Please be
attentive to the brake warning lamp in the
instrument cluster and brake condition mes-
sages in the multifunction display. Especial-
ly for high performance driving, it is
important to maintain the brake system and
have it checked regularly.

302 OperationDriving instructionsCatalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Maintenance Booklet.
Emission control
Certain engine systems serve to keep the
toxic components of the exhaust gases
within permissible limits required by law.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments on the engine should therefore
only be carried out by qualified
Mercedes-Benz Center authorized techni-
cians.
Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly accord-
ing to Mercedes-Benz servicing require-
ments. For details refer to the
Maintenance Booklet.
!To prevent damage to the catalytic
converters, use only premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel
may reach the catalytic converter,
causing it to overheat and potentially
start a fire.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble materials such as grass, hay or leaves
can come into contact with the hot exhaust
system, as these materials could be ignited
and cause a vehicle fire.

303 Operation
Driving instructions
Coolant temperature
During severe operating conditions, e.g.
stop-and-go city traffic, the coolant
temperature may rise to approx. 248°F
(120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause un-
consciousness and possible death.
Do not run the engine in confined areas
(such as a garage) which are not properly
ventilated. If you think that exhaust gas
fumes are entering the vehicle while driving,
have the cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one win-
dow fully open at all times.
iExcessive coolant temperature triggers
a warning message in the multifunction
display (
page 376).
Warning!
G


Driving when your engine is badly over-
heated can cause some fluids, which
may have leaked into the engine com-
partment, to catch fire. You could be se-
riously 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 com-
ing from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.

308 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.


313 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.

376 Practical hintsWhat to do if …During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).Display symbol
Display message
Possible cause/conse-
quence
Possible solution
Ï
Coolant
Stop, engine off
The poly-V-belt could be
broken.

Stop the vehicle and immediately turn off the engine.

Check the poly-V-belt (
page 437).
If it is broken:

Do not continue to drive. Otherwise the engine will overheat
due to an inoperative water pump which may result in dam-
age to the engine. Notify an authorized Mercedes-Benz
Center.
If it is in order:

Do not continue to drive the vehicle with this message dis-
played. Doing so could result in serious engine damage that
is not covered by the Mercedes-Benz Limited Warranty.
Drive immediately to the nearest authorized
Mercedes-Benz Center.

Observe the coolant temperature display (
page 128).
!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.

377 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
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 313).

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.