2011 MERCEDES-BENZ C-Class engine overheat

Vehicle equipment
iThis manual describes all the standard
and optional equipment of your vehicle
which was available at the time of
purchase. Country-specific differences are
possible. Bear in mind that your vehicle
may not feature all functions described
here. This also refers to safety-related
systems and functions.
Engine compartment
Hood
Opening the hood
GWarning
Do not pull the release lever while the vehicle
is in motion. Otherwise, the hood could be
forced open by passing air flow.
This could cause the hood to come loose and
injure you and/or others.
GWarning
Do not open the hood when the engine is
overheated. You could be seriously injured.
Observe the coolant temperature gauge to
determine whether the engine may be
overheated. If you see flames or smoke
coming from the engine compartment, move
away from the vehicle. Wait until the engine
has cooled. If necessary, call the fire
department.
GWarning
There is a risk of injury if the hood is open,
even if the engine is not running.
Some engine components can become very
hot.
To avoid the risk of burns, only touch those
components described in the Operator's
Manual and observe the relevant safety notes.
GWarning
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades.
GWarning
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, diagnostic
socket) of the ignition system:
Rwith the engine running
Rwhile starting the engine
Rwhen the ignition is switched on and the
engine is turned manually
XMake sure that the windshield wipers are
switched off.
GWarning
The windshield wipers and wiper linkage
could be set in motion.
When the hood is open, you or others could
be injured by the wiper linkage.
Make sure that the windshield wipers are
switched off. Remove the SmartKey or make
sure that no ignition position has been
selected with KEYLESS-GO. All indicator
lamps must be off in the instrument cluster.
238Engine compartmentMaintenance and care
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On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 132).
XCheck the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
GWarning
In order to avoid any potentially serious burns:
Ruse 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 display indicates
that the coolant is overheated.
Rdo not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158 ‡ (70 †). Allow the engine to
cool down before removing the cap. The
coolant reservoir contains hot fluid and is
under pressure.
Rusing a rag, slowly turn the cap
approximately 1/2 turn to relieve excess
pressure. If opened immediately, scalding
hot fluid and steam will be blown out under
pressure.
Rdo not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts.
XSlowly turn cap : half a turn counter-
clockwise and allow excess pressure to
escape.
XTurn cap : further counter-clockwise and
remove it.
If the coolant is at the level of marker bar
= in the filler neck when cold, there is
enough coolant in coolant expansion
tank ;.
If the coolant is approximately 0.6 in
(1.5 cm) higher when warm, there is
enough coolant in coolant expansion
tank ;.
XIf necessary, add coolant which has been
tested and approved by Mercedes-Benz.
XReplace cap : and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 310).
Windshield washer system/headlamp
cleaning system
The washer fluid reservoir is used for both the
windshield washer system and the headlamp
cleaning system.
GWarning
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on hot engine parts, because it may
ignite and burn. You could be seriously
burned.
! At temperatures below freezing, always
fill the washer fluid container with a mix of
windshield washer concentrate and
antifreeze additive. There is otherwise a
risk of damaging the windshield washer
system/headlamp cleaning system.
! Only use washer fluid concentrate which
is suitable for plastic lenses. Unsuitable
washer fluid concentrate could damage the
plastic lenses of the headlamps.
! Do not add distilled or de-ionized water to
the washer fluid container. Otherwise, the
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Coolant
Important safety notes
The coolant is a mixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
The cooling system is filled with coolant at the
factory which contains antifreeze/corrosion
inhibitor that ensures protection down to
approximately -35 ‡ (-37 †).
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants and on
filling can be found in the Mercedes-Benz
Specifications for Service Products, MB
Approval 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com . You
can also consult an authorized Mercedes-
Benz Center.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the cooling system will not be
sufficiently protected from corrosion, and
the boiling point will be too low.
If the coolant has antifreeze protection down
to -35 ‡ (-37 †), the boiling point of the
coolant in the pressurized system is
approximately 266 ‡ (130 †).
Your vehicle has a range of aluminum
components. Use of aluminum components
in the engine make it necessary to specifically
match the antifreeze/corrosion inhibitor in
these systems in order to protect the
aluminum parts. Using other antifreeze/
corrosion inhibitors without these
characteristics affects the service life.
The coolant must be used throughout the year
in order to maintain the necessary corrosion
protection and provide protection from
overheating. In the Service Booklet, you can
find information on the intervals for renewal.
The renewal interval is determined by the
coolant type and the cooling system design.
The renewal interval in the Service Booklet is
only valid if the coolant is added or renewed
with Mercedes-Benz approved products.
Therefore, only use MB 326.0 antifreeze/
corrosion inhibitor or another Mercedes-Benz
approved product of the same specification.
Information on other Mercedes-Benz
approved products of the same specification
can be obtained at any authorized Mercedes-
Benz Center or on the Internet at
http://bevo.mercedes-benz.com .
The coolant is checked at every service date
at an authorized Mercedes-Benz Center.
The antifreeze/corrosion inhibitor
concentration in the cooling system should:
R be at least 50%. This will protect the cooling
system against freezing down to around
-35 ‡ (-37 †).
R not exceed 55% (antifreeze protection
down to -49 ‡ (-45 †); otherwise, heat will
not be dissipated as effectively.
If the coolant level is too low, MB 326.0
antifreeze/corrosion inhibitor should be
added. Have the cooling system checked for
leaks.
Windshield and headlamp cleaning
system
GWarning
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on hot engine parts, because it may
ignite and burn. You could be seriously
burned.
XUse MB Windshield Washer Concentrate
MB SummerFit.XAt temperatures above freezing: add 1
part MB SummerFit to 100 parts water, e.g.310Service products and capacitiesTechnical data
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