cooling MERCEDES-BENZ C240 2005 W203 Owner's Manual

53 Getting started
Driving
Problems while driving
The engine runs erratically and misfires

An ignition cable may be damaged.


The engine electronics may not be op-
erating properly.


Unburned gasoline may have entered
the catalytic converter and damaged it.

Give very little gas.

Have the problem repaired by an au-
thorized Mercedes-Benz Center as
soon as possible.The coolant temperature is
above 248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.

Stop the vehicle as soon as possible
and turn off the engine. Allow engine
and coolant to cool.

Check the coolant level and add
coolant if necessary (
page 283).In case of accident
If the vehicle is leaking gasoline:

Do not start the engine under any cir-
cumstances.

Notify local fire and/or police authori-
ties.
If the extent of the damage cannot be de-
termined:

Notify an authorized Mercedes-Benz
Center.
If no damage can be determined on the


major assemblies


fuel system


engine mount:

Start the engine in the usual manner.

175 Controls in detail
Climate control
Climate control panel
Item
1
Left side defroster vent, fixed
2
Left side air vent, adjustable
3
Thumbwheel for air volume control
for left side air vent
4
Thumbwheel for air volume control
for left center air vent
5
Left center air vent, adjustable
6
Right center air vent, adjustable
7
Thumbwheel for air volume control
for right center air vent
8
Thumbwheel for air volume control
for right side air vent
9
Right side air vent, adjustable
a
Right side defroster vent, fixed
b
Climate control panel
iFor draft-free ventilation, move the
sliders for the side air vents2 and9
and center air vents5 and 6 to the
middle position.
Item
1
Air volume control
2
Left side temperature control
3
Right side temperature control
4
Air distribution control
5
Rear window defroster
6
AC cooling on/off (AC
OFF
)
7
Air distribution and air volume
(automatic mode)
8
Air recirculation
9
Defrosting

176 Controls in detailClimate controlThe climate control is operational when-
ever the engine is running. You can oper-
ate the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the modeAC
OFF
is selected
(
page 181).
Warning!
G
When operating the climate control, the air
that enters the passenger compartment
through the air vents in the footwell can be
very hot or very cold (depending on the set
temperature). This may cause burns or frost-
bite on unprotected skin in the immediate
area of the air vents. Always keep sufficient
distance between unprotected parts of the
body and the footwell air vents. If necessary,
change the air flow using the air distribution
controls to direct the air away from the foot-
well air vents (
page 178).
Warning!
G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air
pollution) may require replacement of
the filter before its scheduled interval.
A clogged filter will reduce the air
volume to the interior.
If the vehicle interior is hot, ventilate
the interior before driving off, see
“Opening (Summer opening feature)”
(page 229).
Keep the air intake grille in front of the
windshield free of snow and debris.
Do not obstruct air flow by placing
objects on the air flow-through exhaust
slots below the rear window.

181 Controls in detail
Climate control
Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the climate
control system. The air in the vehicle will
then no longer be cooled or dehumidified.

Press button± (
page 175).
The indicator lamp on the button
comes on.
The cooling function switches off after
a short delay.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.

Press button± (
page 175).
The indicator lamp on the button goes
out.
The air conditioning uses the
refrigerant R134a. This refrigerant is free
of CFCs which are harmful to the ozone
layer.
iCondensation may drip out from under-
neath the vehicle. This is normal and
not an indication of a malfunction.Warning!
G
If you turn off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog
up more quickly. Window fogging may
impair visibility and endanger you and
others.
!If the air conditioning cannot be turned
on again, this indicates that the air
conditioning is losing refrigerant. The
compressor has turned itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Center.

187 Controls in detail
Audio system
Switching off
Remove SmartKey from starter switch.
or

Press M button.
Adjusting the volume

Turn rotary control of N button.
The volume will increase or decrease
depending on the direction turned.Adjusting sound functions
The bass and treble functions are called up
by pressing the O button.
Settings for bass and treble are stored
separately for the AM and FM wavebands,
weather band, CD mode and telephone
mode.
Bass

Press O button repeatedly until BASS
appears in the display.

Press
+ or
– soft key to increase or
decrease tone level accordingly.
or

Press
RES
soft key briefly to reset bass
tones to their center level.
The radio switches back to the
standard radio menu eight seconds
after the last soft key is pressed.
iShould excessively high temperatures
occur while the audio system is being
operated, the display will dim. If tem-
peratures continue to rise,
HIGH TEMP

will appear in the display, after which
the audio system will be switched off
for a cooling-down period.
iIf your vehicle equipment includes a
Mercedes-Benz specified mobile
telephone*, you can adjust its volume
separately from the volume of the
audio system while the telephone is
being used.

283 Operation
Engine compartment
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.
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 turn to the left to
release any excess pressure.

Continue turning the cap to the left 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 394).
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
approximately
1/2 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.

316 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 283).

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.

318 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
•
Coolant
Stop, engine off!
The poly-V-belt could be broken.

Stop immediately and 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 serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.

Observe the coolant temperature gauge in
the instrument cluster (
page 24).

Drive immediately to the nearest authorized
Mercedes-Benz Center.
Coolant
Visit workshop.
The cooling fan for the coolant is
malfunctioning.

Observe the coolant temperature gauge in
the instrument cluster (
page 24).

Have the fan replaced as soon as possible.

388 Technical dataFuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants, etc.
Front axle
C2404MATIC
C3204MATIC
0.5 US qt (0.46 l)
Hypoid gear oil SAE 85 W 90
Transfer case
C2404MATIC
C3204MATIC
approx. 0.62 US qt (0.59 l)
MB Transfer case fluid
Power steering
approx. 1.1 US qt (1.0 l)
MB Power Steering Fluid (Pentosin CHF 11S)
Front wheel hubs
approx. 2.1 oz (60 g) each
High temperature roller bearing grease
Brake system
0.5 US qt (0.5 l)
MB Brake Fluid (DOT 4+)
Cooling system
C 230 Kompressor (all models)
C240 (all models)
C320 (all models)
C55AMG
approx. 5.9 US qt (5.6 l)
approx. 6.8 US qt (6.4 l)
approx. 6.8 US qt (6.4 l)
approx. 12.8 US qt (12.0 l)
MB 325.0 Anticorrosion/antifreeze agent
Fuel tank
including
a reserve of
16.4 US gal (62.0 l)
2.1 US gal (8.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)Flexible Fuel Vehicle (identified by a label
reading Premium gasoline or E85 only! on
fuel filler flap):
Alternative fuel: Ethanol fuel (E85)

394 Technical dataFuels, coolants, lubricants, etc.Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which
provides:

Corrosion protection


Freeze protection


Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -22°F (-30°C) and
corrosion protection.
If the antifreeze mixture is effective
to -22°F (-30°C), the boiling point of the
coolant in the pressurized cooling system
is reached at approx. 266°F (130°C).The coolant solution must be used
year-round to provide the necessary corro-
sion protection and increase boil-over
protection. Refer to Maintenance Booklet
for replacement interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable
if MB 325.0 anticorrosion/antifreeze
solution or other Mercedes-Benz approved
products of equal specification (see
Factory Approved Service Products
pamphlet) are used to renew the coolant
concentration or bring it back up to the
proper level.
To provide important corrosion protection,
the solution must be at least 45%
anticorrosion/antifreeze [equivalent to
freeze protection to approx. -22°F
(-30°C)]. If you use a solution that is more than 55%
anticorrosion/antifreeze [freeze
protection to approx. -49°F (-45°C)], the
engine temperature will increase due to
the lower heat transfer capability of the
solution. Therefore, do not use more than
this amount of anticorrosion/antifreeze.
If the coolant level is low, water and
MB 325.0 anticorrosion/antifreeze should
be used to bring it up to the proper level
(have cooling system checked for signs of
leakage). Please make sure the mixture is
in accordance with label instructions.
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality,
consult an authorized Mercedes-Benz
Center.