engine overheat MERCEDES-BENZ C55AMG 2006 W203 Owner's Manual

123 Controls in detail
Instrument cluster
Coolant temperature gauge
The coolant temperature gauge is on the
left side in the instrument cluster
(
page 24).
Trip odometer
Make sure you are viewing the trip
odometer and main odometer in the
multifunction display (
page 125).
If it is not displayed, press buttonè
orÿ on the multifunction steering
wheel (
page 126) until the trip
odometer appears in the multifunction
display.
Press and hold the reset button in the
instrument cluster (
page 122) until
the trip odometer is reset.
Warning!G

Driving when your engine is badly
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 vehicle
and do not stand near the vehicle until the
engine has cooled down.
!
Excessive coolant temperature triggers
a warning in the multifunction display
(
page 368).
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.
i
During severe operating conditions,
e.g. stop-and-go traffic, the coolant
temperature may rise close to 248°F
(120°C).

285 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.
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the
operating temperature has been reached.
When starting off on a slippery surface, do
not allow a drive wheel to spin for an
extended period with the ESP
® switched
off. Doing so may cause serious damage to
the drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Parking
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
prevent overheating of the brakes and
reduces brake pad wear.
!
Simultaneously depressing the
accelerator pedal and applying the
brake reduces engine performance and
causes premature brake and drivetrain
wear.
!
Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
move gear selector lever to positionP.
When parking on hills, always turn front
wheels towards the road curb.
Warning!G
Do not park this vehicle in areas where
combustible 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.
To reduce the risk of personal injury as a re-
sult of vehicle movement, before
turning off
the engine and leaving the vehicle always:

Keep right foot on brake pedal.

Firmly depress parking brake pedal.

291 Operation
Driving instructions
Catalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial
control of the pollutants in the exhaust
emissions. Keep your vehicle in proper
operating condition by following our
recommended maintenance instructions
as outlined in your Maintenance Booklet.Emission control
Certain systems of the engine 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
according to factory specifications. Any
adjustments on the engine should,
therefore, be carried out only 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
according to Mercedes-Benz servicing
requirements. For details refer to the
Maintenance Booklet.
!
To prevent damage to the catalytic
converters, only use 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
operate this vehicle in areas where combus-
tible 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.

292 Operation
Driving instructions
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant
temperature may rise close to
approximately 248°F (120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious
engine 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
unconsciousness 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
window fully open at all times.
Warning!G

Driving when your engine is badly
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 vehicle
and do not stand near the vehicle until the
engine has cooled down.

298 Operation
Engine 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 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
(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.
i
Do 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 Mercedes-Benz
Center.

302 Operation
Engine compartment
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Coolant expansion tank
2Cap
Using a rag, turn cap2 slowly approx-
imately one half counterclockwise to
release any excess pressure.
Continue turning the cap counterclock-
wise and remove it.
The coolant level is correct if the level

for cold coolant: reaches the black
top part of the reservoir

for warm coolant: is approx. 0.6 in
(1.5 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information on coolant, see
“Coolants” (
page 439).
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
approximately1/2 turn to relieve excess
pressure. If opened immediately, scald-
ing hot fluid and steam will be blown out
under 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.

365 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
#Battery Alternator
Visit workshopThe battery is no longer charging.
Possible causes:

broken poly-V-belt

alternator malfunctioning
Stop immediately and check the
poly-V-belt in a safe location or as
soon as it is safe to do so.
If it is broken:
Do not continue to drive. Otherwise
the engine will overheat due to an
inoperative water pump which may
result in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest
authorized Mercedes-Benz Center.
Low voltage
Charge batteryThe battery has insufficient voltage.Start the engine (page 45).
Low voltage
Consumers offThe battery has insufficient voltage.Turn off unnecessary electrical
consumers.

367 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
BCoolant
Check levelThe coolant level is too low.Add coolant (page 301).
If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Center.
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
the 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
engine damage.

368 Practical hints
What 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 symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop, engine off!The coolant is too hot. Stop the vehicle in a safe location and
turn off the engine.
Only start the engine again after the
message disappears. You could
otherwise damage the engine.
Warning!G
Driving when your engine is badly over-
heated 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.

369 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop, engine off!The poly-V-belt could be broken.Stop the vehicle in a safe location and
immediately turn off the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the engine
will overheat due to an inoperative water pump
which may result in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:
Do not continue to drive the vehicle with this
message displayed. Doing so could result in seri-
ous engine damage that is not covered by the
Mercedes-Benz Limited Warranty.
Observe the coolant temperature gauge in the in-
strument cluster (
page 24).
Drive immediately to the nearest authorized Mer-
cedes-Benz Center.
Coolant
Visit workshopThe cooling fan for the coolant is
malfunctioning.Observe the coolant temperature gauge in the in-
strument cluster (
page 24).
Have the fan replaced as soon as possible.