2017 MERCEDES-BENZ GLC engine overheat

X
Reac h int o th e gap, pull hoo d catch handle D
up and lift th e hood.
If you lift th e hoo d by approximately 15 in
(40 cm), th e hoo d is opened and held open
automatically by th e gas-filled strut .
Closing the hood X
Lowe r th e hoo d and let it fall from a height of
approximately 8 in (20 cm).X
Chec k that th e hoo d has engage d properly.
If th e hoo d can be raised slightly, it is no t
properly engaged. Open it again and close it
wit h a littl e mor e force .
Radiator Do no t cover up th e radiator, suc h as wit h a
thermal mat or insec t protection cover . Other -
wise, th e value s of th e European on-board diag-
nostics may be affected. Some of these read -
ing s are require d by law and mus t be accurat e at
all times .
Engine oil
Important safety notes
G WARNIN G
Certain component s in th e engin e compart-
ment, suc h as th e engine, radiato r and part s
of th e exhaust system, can become ver y hot .
Workin g in th e engin e compartmen t poses a
ris k of injury.
Wher e possible, let th e engin e cool down and
touch only th e component s describe d in th e
following. G WARNIN G
The engin e compartmen t contain s moving
components. Certain components, suc h as
th e radiato r fan , may continu e to run or start
again suddenly when th e ignition is off . There
is a ris k of injury.
If you need to do any wor k inside th e engin e
compartment: R
switch off th e ignition R
never reac h int o th e area wher e there is a
ris k of danger from moving components,
suc h as th e fan rotation area R
remove jewelr y and watches R
keep items of clothing and hair , for exam-
ple, away from moving part s
G WARNIN G
If engin e oil comes int o contact wit h hot com-
ponents in th e engin e compartment, it may
ignite. There is a ris k of fir e and injury.
Mak e sur e that engin e oil is no t spilled next to
th e filler neck . Let th e engin e cool down and
thoroughly clean th e engin e oil off th e com-
ponents before starting th e engine.
G WARNIN G
Opening th e hoo d when th e engin e is over-
heated or when there is a fir e in th e engin e
compartmen t could expos e you to hot gase s
or other servic e products . There is a ris k of
injury.
Let an overheate d engin e cool down before
opening th e hood. If there is a fir e in th e
engin e compartment, keep th e hoo d closed
and contact th e fir e department.
General notes
Dependin g on your driving style, th e vehicl e
consumes up to 0. 9 US qt (0. 8 l) of oil per
60 0 mile 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 compartment 307
Maintenance and care Z

Where possible, let the engine cool down and
touch only the components described in the
following.
G WARNING
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: R
switch off the ignition R
never reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area R
remove jewelry and watches R
keep items of clothing and hair, for exam-
ple, away from moving parts
G WARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
G WARNING
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. Checking coolant level
Checking the coolant level (example) X
Park the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down. X
Turn the SmartKey to position H in the igni-
tion lock ( Y
page 132).
or X
Press the Start/Stop button twice on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function ( Y
page 133). X
Check the coolant temperature display in the
instrument cluster ( Y
page 36).
The coolant temperature must be below
158 ‡ (70 †). X
Turn the SmartKey to position Z in the igni-
tion lock ( Y
page 132).
or X
Press the Start/Stop button once on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function ( Y
page 133). X
Slowly turn cap C half a turn counter-clock-
wise and allow excess pressure to escape. X
Turn cap C further counter-clockwise and
remove it.
If the coolant is at the level of marker bar

! Only use the fuel recommended. Operating
the vehicle with other fuels can lead to dam-
age to the fuel system, engine and exhaust
system.
! Do not use the following: R
Gasoline with more than 10% ethanol R
E100 (1 00% ethanol)R
Gasoline with methanol R
M100 (1 00% methanol)R
Gasoline with metalliferous additives R
Diesel
Do not mix such fuels with the fuel recom-
mended for your vehicle.
! 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: R
Only 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. R
Do not drive at the maximum speed. R
Avoid sudden acceleration and engine
speeds over 3,000 rpm.
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.
i For 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 ( Y
page 149).
Additives
! Operating the engine with fuel additives
added later can lead to engine failure. Do not
mi x 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
G WARNING
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: R
marine diesel R
heating oil R
bio-diesel R
vegetable oil R
gasoline R
paraffin R
kerosene
Do not mix such fuels with diesel fuel and do
not use any special additives. Otherwise,
engine damage may occur.
! In countries outside the EU, only use low-
sulfur Euro diesel with a sulfur content of
under 50 ppm. Otherwise, the emission con-
trol system could be damaged.366
Service products and filling capacities
Technical data

Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have 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
( Y
page 364).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the fol-
lowing tasks: R
Anti-corrosion protection R
Antifreeze protection R
Raising 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 †).
The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should: R
be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †). R
not exceed 55% (antifreeze protection down
to -49 ‡[ -45 †]) . Otherwise , hea t will no t be
dissipated as effectively.
Mercedes-Ben z recommends an antifreeze/
corrosion inhibitor concentrat e in accordance
wit h MB Specification s fo r Servic e Products
310.1.
i Whe n th e vehicle is first delivered, it is filled
wit h a coolan t mixture that ensures adequat e
antifreez e an d anti-corrosio n protection .
i The coolan t is checke d wit h ever y mainte-
nanc e interval at a qualifie d specialis t work-
shop.
Filling capacities
Model Capacity
GLC 300 d 4MATIC
10.6 US qt (10.0 l)
Mercedes-AMG
GLC 43 4MATIC 12.2 US qt (11.5 l)
Al l ot her models
9.5 US qt (9.0 l) Windshield washer system
Important safety notes
G WARNING
Windshield washer concentrate could ignite if
it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or MB
WinterFit. Unsuitable washer fluid could dam-
age the plastic lenses of the headlamps.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
Do not use distilled or de-ionized water. Other-
wise, the level sensor may give a false reading.
When handling washer fluid, observe the impor-
tant safety notes on service products
( Y
page 364).
At temperatures above freezing: X
Fill the washer fluid reservoir with a mixture of
water and windshield washer fluid, e.g. MB
SummerFit.
Add 1 part MB SummerFit to 100 parts water.
At temperatures below freezing: X
Fill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB WinterFit.
For the correct mixing ratio refer to the infor-
mation on the antifreeze reservoir.
i Add windshield washer fluid, e.g. MB Sum-
merFit or MB WinterFit, to the washer fluid all
year round.
Climate control system refrigerant
Important safety notes
The climate control system of your vehicle is fil-
led with refrigerant R ‑ 134a.
The instruction label regarding the refrigerant
type used can be found on the radiator cross
member.Service products and filling capacities 369
Technical data Z