2018 MERCEDES-BENZ C-CLASS SEDAN engine overheat

Display messagesPossible causes/consequences andMSolutions
#
See Operator'sMan ‐ual
The battery is no tbein gcharged.
A warning tone also sounds.
Possibl ecauses are:
Radefective alternato r
Ratorn poly-V-belt
Ramalfunction in th eelectronics
!Do no tcontinu edriving. The engin ecould otherwise overheat.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XConsult aqualified specialist workshop .
#
StopVehicl eSeeOperator' sManual
The battery is no longer bein gcharged and th econdition of charg eis
to olow.
A warning tone also sounds.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XObserv eth einstruction sin th e# See Operator' sManualdisplay message .
XConsultaqualified specialist workshop .
#
StopVehicl eLeaveEngine Runnin g
The battery condition of charg eis to olow.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XLeav eth eengin erunning.
XWait until th edisplay message disappear sbefore pullin gaway.
#
Start Engine SeeOperator' sManual
The engin eis switched off and th econdition of charg eis to olow.
XSwitc hoff electrical consumer sthat you do no tneed, suc has th e
rear window defroste rand interior lighting .
XLeaveth eengin erunnin gfor afew minute sor drive alon gdistance.
The battery is bein gcharged.
244Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
TirePressure Moni‐tor Inoperative NoWheel Sensor s
The wheels mounte ddo no thav e a suitable tire pressur esensor .The
tire pressur emonitor is deactivated.
XMoun twheels wit hsuitable tire pressur esensors.
The tire pressur emonitor is activated automatically after drivin gfor
a few minutes.
Tir ePress.Monito rInoperativeThe tire pressur emonitor is faulty.
XVisit aqualified specialist workshop .
Tires OverheatedThe tire temperature monitoring function is no tavailable in all vehi-
cles.
At least on etire has overheated. Affecte dtires are shown in red .At
temperatures close to th elimi tvalue ,th etires are shown in yellow .
XDrive moreslowly.
Tires Overheate dDecrease SpeedThe tire temperature monitoring function is no tavailable in all vehi-
cles.
At least on etire has overheated.
GWARNIN G
Overheated tires can burst, particularly at high speeds .
XDrive moreslowly so that th etires cool down .
Vehicle
Display messagesPossible causes/consequences and MSolutions
Shiftto'P'or'N'to Start EngineYou haveattempte dto start th eengin ewit hth etransmission in posi-
tion korh.
XShift th etransmission to position jori .
Apply Brake toShift fro m'P'You hav eattempte dto shift th etransmission to position h,kori
without depressing th ebrak epedal .
XDepress th ebrak epedal .
ToDeselectPorN,Depres sBrake andStart Engine
Wit hth eengin eswitched off ,you hav eattempte dto shift th etrans -
mission out of position jori intoanother transmission position .
XDepress thebrak epedal .
XStart th eengine.
To Engage Trans‐miss. Position RFirst DepresstheBrake
You hav eattempte dto shift from position hto position k.
XDepress thebrak epedal .
XShift th etransmission to position k.
254Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
StopVehicl eLeaveEngineRunnin gWaitTransmission Cool‐ing
The transmission has overheated. Pullin gaway can be temporarily
impaire dor no tpossible.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XLeav eth eengin erunning.
XWait until th edisplay message disappear sbefore pullin gaway.
NThe trunk lid is open .
XCloseth etrunk lid.
MThe hoo dis open . Awarning tone also sounds.
GWARNIN G
The open hoo dmay bloc kyour vie wwhen th evehicl eis in motion .
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XCloseth ehood.
CAt least on edoor is open . Awarning tone also sounds.
XClos eall th edoors.
_
Rea rLef tBackrestNot Latche dorRea rRight Backrest NotLatche d
Vehiclewit hthrough-loading feature in th erear bench seat :
The backrest in th erear is no tengage don th eleft-han dand/o rright -
han dside .
XPush th ebackrest bac kuntil it engages.
_
Rea rCenter Back‐res tNot Engage d
Vehiclewit hthrough-loading feature in th erear bench seat :
The center rear seat backrest is no tengaged.
XPush th ebackrest bac kuntil it engages.
256Display messages
On-board computer and displays

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 161).
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 306).
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 161).
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 306).
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.
266Warning 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
Hybrid vehicles: be sure to observe the notes
in the supplementary instructions. Otherwise,
you may not recognize dangers.
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.
Engine compartment303
Maintenance and care
Z

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.
Hybrid vehicles: be sureto observ eth enote s
in th esupplementary instructions. Otherwise,
you may no trecogniz edangers.
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.
304Engine compartment
Maintenance and care

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 136).
or
XPress th eStart/Sto pbutto ntwice on vehicles
wit hKEYLESS-GO or th eKEYLESS-GO start
function (
Ypage 137).
XCheckth ecoolan ttemperature display in th e
instrumen tcluste r (Ypage 37).
The coolan ttemperature mus tbe belo w
15 8 ‡ (70 †).
XTurn th eSmartKey to position gin th eigni-
tion loc k (Ypage 136).
or
XPress th eStart/Sto pbutto nonce on vehicles
wit hKEYLESS-GO or th eKEYLESS-GO start
function (
Ypage 137).
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;.
306Engine compartment
Maintenance and care

!To ensure the longevity and full perform-
ance of the engine, only premium-grade
unleaded gasoline must be used.
If standard unleaded gasoline is unavailable
and you have to refuel with unleaded gasoline
of a lower grade, observe the following pre-
cautions:
ROnly fill the fuel tank to half full with regular unleaded gasoline and fill the rest with pre-
mium-grade unleaded gasoline as soon as
possible.
RDo not drive at the maximum speed.
RAvoid sudden acceleration and engine
speeds over 3,000 rpm.
You will usually find information about the fuel
grade on the fuel pump. If you cannot find the
label on the fuel pump, ask the gas station staff.
iFor further information, consult a qualified
specialist workshop or visit
http://www.mbusa.com (USA only).
As a temporary measure, if the recommended
fuel is not available, you may also use regular
unleaded gasoline with an octane rating of
87 AKI/91 RON. This may reduce engine per-
formance and increase fuel consumption. Avoid
driving at full throttle and sudden acceleration.
Never refuel using gasoline with a lower AKI.
Information on refueling (
Ypage 156).
Additives
!Operating the engine with fuel additives
added later can lead to engine failure. Do not
mix fuel additives with fuel. This does not
include additives for the removal and preven-
tion of residue buildup. gasoline must only be mixed with additives recommended by
Mercedes-Benz. Comply with the instructions
for use on the product label. More information
about recommended additives can be
obtained from any authorized Mercedes-Benz
Center.
Mercedes-Benz recommends that you use bran- ded fuels that have additives.
The fuel quality available in some countries may
not be sufficient. Residue could build up in the
fuel injection system as a result. In such cases,
and in consultation with an authorized
Mercedes-Benz Center, the fuel may be mixed
with the cleaning additive recommended by
Mercedes-Benz. You must observe the notes
and mixing ratios specified on the container.
Diesel
Fuel grade
GWARNING
If you mix diesel fuel with gasoline, the flash
point is lower than that of pure diesel fuel.
When the engine is running, exhaust system
components could overheat without being
noticed. There is a risk of fire.
Never refuel with gasoline. Never mix gasoline with diesel fuel.
!Refuel only using diesel fuel that conforms
to European standard EN 590 or an equivalent
specification. Fuel that does not conform to
EN 590 can lead to increased wear and dam-
age the engine and exhaust system.
!Do not use the following:
Rmarine diesel
Rheating oil
Rbio-diesel
Rvegetable oil
Rgasoline
Rparaffin
Rkerosene
Do not mix such fuels with diesel fuel and do
not use any special additives. Otherwise,
engine damage may occur.
!Vehicles with diesel particle filters: in
countries outside the EU, only use low sulfur
Euro diesel with a sulfur content of under
50 ppm. Otherwise, the emission control sys-
tem could be damaged.
!Vehicles without a diesel particle filter:
in countries where only diesel fuel with a high
sulfur content is available, you will need to
carry out your vehicle's oil change at shorter
intervals. Further information on oil change
intervals can be obtained at a qualified spe-
cialist workshop.
You will usually find information about the fuel
quality on the pump. If you cannot find the label
on the fuel pump, ask the gas station staff.
Information on refueling (
Ypage 156).
Service products and filling capacities363
Technical data
Z