2018 MERCEDES-BENZ C-CLASS COUPE engine overheat

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 147).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 289).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature gauge is below the
red marking. Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running. A warning
tone also sounds.
The coolant temperature gauge has reached the red marking. The airflow to the
engine radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some fluids which
may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 147).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 289).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
252Warning and indicator lamps in the instrument cluster
On-board computer and displays

Engine compartment
Hood
Important safety notes
GWARNING
If the hood is unlatched, it may open up when the vehicle is in motion and block your view.
There is a risk of an accident.
Never unlatch the hood while driving. Before
every trip, ensure that the hood is locked.
GWARNING
When opening and closing the hood, it may
suddenly fall into the closed position. There is a risk of injury to persons within range of
movement of the hood.
Open and close the hood only when no one is
within its range of movement.
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
GWARNING
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There is a risk of injury.
If you need to do any work inside the engine
compartment:
Rswitch off the ignition
Rnever reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
Opening the hood
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
!Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield wip-
ers or the hood.
XMake sure that the windshield wipers are
turned off.
XPull release lever :on the hood.
The hood is released.
286Engine compartment
Maintenance and care

XReachint oth egap, pull hoo dcatch handle ;
up and lift th ehood.
If you lift th ehoo dby approximately 15 in
(40 cm), th ehoo dis opened and held open
automatically by th egas-filled strut .
Closing the hood
XLowerth ehoo dand let it fall from aheight of
approximately 8in (20 cm).
XChec kthat th ehoo dhas engage dproperly.
If th ehoo dcan be raised slightly, it is no t
properly engaged. Open it again and close it
wit h a littlemor eforce .
Radiator
Do no tcover up th eradiator, suc has wit h a
thermal mat or insec tprotection cover .Other -
wise, th evalue sof th eEuropean on-board diag-
nostics may be affected. Some of these read -
ing sare require dby law and mus tbe accurat eat
all times .
Engine oil
Important safety notes
GWARNIN G
Certain component sin th eengin ecompart-
ment, suc has th eengine, radiato rand part s
of th eexhaust system, can become ver yhot .
Workin gin th eengin ecompartmen tposes a
ris kof injury.
Wher epossible, let th eengin ecool down and
touch only th ecomponent sdescribe din th e
following.
GWARNIN G
The engin ecompartmen tcontain smoving
components. Certain components, suc has
th eradiato rfan ,may continu eto run or start
again suddenly when th eignition is off .There
is aris kof injury.
If you need to do any wor kinside th eengin e
compartment:
Rswitch off th eignition
Rnever reac hint oth earea wher ethere is a
ris kof danger from moving components,
suc has th efan rotation area
Rremove jewelr yand watches
Rkeep items of clothing and hair ,for exam-
ple, away from moving part s
GWARNING
If engin eoil comes int ocontact wit hhot com-
ponents in th eengin ecompartment, it may
ignite. There is aris kof fir eand injury.
Mak esur ethat engin eoil is no tspilled next to
th efiller neck .Let th eengin ecool down and
thoroughly clean th eengin eoil off th ecom-
ponents before starting th eengine.
GWARNIN G
Opening th ehoo dwhen th eengin eis over-
heated or when there is afir ein th eengin e
compartmen tcould expos eyou to hot gase s
or other servic eproducts .There is aris kof
injury.
Let an overheate dengin ecool down before
opening th ehood. If there is afir ein th e
engin ecompartment, keep th ehoo dclosed
and contact th efir edepartment.
General notes
Dependin gon your driving style, th evehicl e
consumes up to 0. 9US qt (0. 8l) of oil per
60 0mile s(1000 km). The oil consumption may
be higher than this when the vehicle is new or if
you frequently drive at high engine speeds.
Depending on the engine, the oil dipstick may be
in a different location.
Engine compartment287
Maintenance and care
Z

Additional service products
Import ant safety notes
GWARNIN G
Certain component sin th eengin ecompart-
ment, suc has th eengine, radiato rand part s
of th eexhaust system, can become ver yhot .
Working in th eengin ecompartmen tposes a
ris kof injury.
Wher epossible, let th eengin ecool down and
touch only th ecomponent sdescribed in th e
following.
GWARNIN G
The engin ecompartmen tcontain smoving
components. Certain components, suc has
th eradiato rfan ,may continu eto run or start
again suddenly when th eignition is off .There
is aris kof injury.
If you need to do any wor kinside th eengin e
compartment:
Rswitch off th eignition
Rnever reac hint oth earea wher ethere is a
ris kof danger from moving components,
suc has th efan rotation area
Rremove jewelr yand watches
Rkeep items of clothing and hair ,for exam-
ple, away from moving part s
GWARNING
The coolin gsystem is pressurized, particularly
when th emotor is warm .If you open th ecap ,
you could be scalded if hot coolan tsprays out .
There is aris kof injury.
Let th eengin ecool down before you open th e
cap .Wear gloves and eye protection .Slowly
open th ecap to reliev epressure.
GWARNIN G
Opening th ehoo dwhen th eengin eis over-
heated or when there is afir ein th eengin e
compartmen tcould expos eyou to hot gase s
or other servic eproducts .There is aris kof
injury.
Let an overheate dengin ecool down before
opening th ehood. If there is afir ein th e
engin ecompartment, keep th ehoo dclosed
and contact th efir edepartment.
Checking coolant level
Checking th ecoolan tlevel (example)
XPark th evehicl eon alevel surface.
Only chec kth ecoolan tlevel when th evehicl e
is on alevel surfac eand th eengin ehas cooled
down .
XTurn th eSmartKey to position 2in th eigni-
tion loc k (Ypage 126).
or
XPress th eStart/Sto pbutto ntwice on vehicles
wit hKEYLESS-GO or th eKEYLESS-GO start
function (
Ypage 127).
XCheckth ecoolan ttemperature display in th e
instrumen tcluste r (Ypage 36).
The coolan ttemperature mus tbe belo w
15 8 ‡ (70 †).
XTurn th eSmartKey to position gin th eigni-
tion loc k (Ypage 126).
or
XPress th eStart/Sto pbutto nonce on vehicles
wit hKEYLESS-GO or th eKEYLESS-GO start
function (
Ypage 127).
XSlowly tur ncap :half atur ncounter-clock -
wise and allow excess pressur eto escape.
XTurn cap :further counter-clockwise and
remove it .
If th ecoolan tis at th elevel of marke rbar =
in th efiller neck when cold, there is enough
coolan tin coolan texpansion tan k;.
If th ecoolan tlevel is approximately 0. 6in
(1. 5cm) abov emarke rbar =in th efiller neck
when warm ,there is enough coolan tin expan -
sion tan k;.
Engine compartment289
Maintenance and care
Z

Filling capacities
The followingvalue srefer to an oil chang e
includin gth eoil filter.
ModelCapacit y
C3007.4US qt (7.0l)
C 300 4MATIC
Mercedes-AMG
C 43 4MATIC6.9 US qt (6.5 l)
Mercedes-AMG
C 63
Mercedes-AMG
C 63 S9.5 US qt (9.0l)
Additives
!Do not use any additives in the engine oil.
This could damage the engine.
Brake fluid
GWARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake
fluid is too low, vapor pockets may form in the
brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
When handling brake fluid, observe the impor-
tant safety notes on service products
(
Ypage 344).
The brake fluid change intervals can be found in
the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval 331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or
on the Internet at
http://bevo.mercedes-benz.co m.
iHave the brake fluid regularly replaced at a
qualified specialist workshop in accordance
with the replacement intervals and the replacement confirmed in the Maintenance
Booklet.
Coolant
Important safety notes
GWARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
!Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
!Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
iHave the coolant regularly replaced at a
qualified specialist workshop and the replace-
ment confirmed in the Maintenance Booklet.
Comply with the important safety notes for ser-
vice products when handling coolant
(
Ypage 344).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the fol-
lowing tasks:
RAnti-corrosion protection
RAntifreeze protection
RRaising the boiling point
If the coolant has antifreeze protection down to
-35 ‡ (-37 †), the boiling point of the coolant
during operation is approximately 266 ‡
(130 †).
Service products and filling capacities347
Technical data
Z