2013 MERCEDES-BENZ GLK-CLASS SUV engine overheat

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your
vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 27).Important safety notes
G
WARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situation permits. If you are

not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary. G
WARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
You must observe the legal requirements for
the country in which you

are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the multifunction display. You should therefore
make sure your vehicle is operating safely at
all times. Otherwise, a vehicle that is not
operating safely may cause an accident.
For an overview, see the instrument panel
illustration (
Y page 31). Displays and operation
Coolant temperature display
G
WARNING
Opening the hood when the engine is
overheated 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.
The coolant temperature gauge is in the
instrument cluster on the left-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †).
! A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over
248 ‡(120 †), do not continue driving. The
engine will otherwise be damaged. Tachometer
The red band in the

tachometer indicates the
engine's overrevving range.
! Do not drive in the overrevving range, as
this could damage the engine.
The fuel supply is interrupted to protect the
engine when the red band is reached. 216
Displays and operation
On-board computer and displays

Display messages Possible causes/consequences and
0050 Solutions00AC
Coolant Too Hot
Stop Vehicle Turn
Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
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.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †).
Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating
conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). 244
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
0050 Solutions003D The battery is not being charged.
A warning tone also sounds.
Possible causes are:
R
a defective alternator
R a torn poly-V-belt
R a malfunction in the electronics
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Open the hood.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The
engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged:
X Visit a qualified specialist workshop. 00B2
Check Engine Oil
At Next Refueling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X
Check the oil level when next refueling, at the latest
(Y page 301).
X If necessary, add engine oil ( Y page 301).
X Have the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.
! Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.com. 00B6
Fuel Level Low The fuel level has dropped into the reserve range.
X
Refuel at the nearest gas station. 00A8 There is only a very small amount of fuel in the fuel tank.
X
Refuel at the nearest gas station without fail. Display messages
245
On-board computer and displays Z

Problem Possible causes/consequences and
0050 Solutions00AC
The 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
malfunctioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Check the coolant level and add coolant (Y page 302). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X At coolant temperatures below 248 ‡ (120 †) drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic. 00AC
The red coolant
warning lamp comes on
while the engine is
running.
A
warning tone
also sounds. The coolant temperature has exceeded 248 ‡ (120 †). The
airflow
to the
engine radiator
may be blocked or the coolant level
may be too low.
G WARNING
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.
X Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 160).
X Wait until the engine has cooled down.266
Warning and indicator lamps in the instrument cluster
On-board computer and displays

A qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center, will reset
the ASSYST PLUS service interval display
after the service work has been carried out.
You can also obtain further information on
maintenance work, for example.
Special service requirements
The specified maintenance interval takes only
the normal operation of the vehicle into
account. Under arduous operating
conditions
or increased load on the vehicle,
maintenance work must be carried out more
frequently, for example:
R regular city driving with frequent
intermediate stops
R if the vehicle is primarily used to travel
short distances
R use
in mountainous terrain or on poor road
surfaces
R if the engine is often left idling for long
periods
Under these or similar conditions, have, for
example, the air filter, engine oil and oil filter
replaced or changed more frequently. Under
arduous operating conditions, the tires must
be checked more often. Further information
can be obtained at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz
Center.
Driving abroad An extensive Mercedes-Benz Service network
is also available in other countries. You can
obtain further information from any
authorized Mercedes-Benz Center. Engine compartment
Hood
Important safety notes G
WARNING
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. G
WARNING
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. G
WARNING
Certain components in the engine
compartment, 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. G
WARNING
Opening the hood when the engine is
overheated 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. 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. Engine compartment
299
Maintenance and care
Z

Gasoline
Fuel grade
!
Do not use diesel to
refuel vehicles with a
gasoline engine. Do not switch on the
ignition if you accidentally refuel with the
wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the
wrong fuel could result in damage to the
fuel system and the engine. The repair
costs are high. Notify a qualified specialist
workshop and have the fuel tank and fuel
lines drained completely.
! You should only refuel with unleaded
premium-grade gasoline as this avoids
damaging the catalytic converter.
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
! To ensure the longevity and full
performance of the engine, only premium-
grade unleaded gasoline may be used.
If there is no premium-grade unleaded
gasoline available and regular unleaded
gasoline must be used, please observe the
following precautions:
R only fill the fuel tank to half full with
regular unleaded gasoline and fill the rest
with premium-grade unleaded gasoline
as soon as possible.
R do not drive at the maximum speed.
R avoid sudden acceleration.
R if the vehicle is carrying a light load, e.g.
two passengers without luggage, do not
allow the engine to rev above 3000 rpm.
R if the vehicle is fully loaded or is being
operated in mountainous terrain, do not
depress the accelerator pedal further
than 00C3 of the pedal travel.
Only refuel using premium-grade unleaded
gasoline with a minimum octane rating of 91. Reformulated Gasoline (RFG) and/or
unleaded
gasoline
with additives
can

be used.
The concentration of additives in the fuel,
however, must not exceed 10%, e.g.:
R Ethanol
R TAME
R ETBE
R IPA
R TBA
For MTBE, the concentration should not
exceed 15%.
The concentration of methanol in gasoline,
including other additives, must not exceed
3%.
Using mixtures of methanol and ethanol is not
permitted. Gasohol, a mixture of 10% ethanol
and 90% unleaded gasoline may be used.
All of these blends must fulfill the fuel
requirements, e.g.:
R knock resistance
R boiling point
R vapor pressure
You will usually find information about the fuel
grade on the pump. If you cannot find the
label on the pump, ask the staff for
assistance.
i For more information, contact a qualified
specialist workshop.
Information on refueling (Y page 154).
Additives
! Operating the engine with fuel additives
can increase wear and tear to the fuel
system high-pressure pump and lead to
contamination of the entire fuel system.
The repair costs are high. This does not
include additives for the removal and
prevention of residue buildup. gasoline
must only be mixed with additives
recommended by Mercedes-Benz. More
information about recommended additives
can be obtained from any authorized
Mercedes-Benz Center. Service products and filling capacities
367
Technical data Z

One of the main problems of poor fuel quality
is the forming of deposits that are created
during the gasoline combustion process.
Mercedes-Benz recommends that you use
branded fuels that have additives.
If you use fuels without these additives over
a longer period of
time,
carbon deposits may
build up. These deposits form at the inlet
valves and in the combustion chamber in
particular.
This could lead to engine problems, e.g.:
R longer engine warm-up phase
R uneven idle
R engine noise
R misfiring
R loss of power
Carbon deposits may form if the availability
of gasoline with relevant additives is
insufficient (in certain regions). In this case,
Mercedes-Benz recommends additives
approved for use in Mercedes-Benz vehicles;
see http://bevo.mercedes-benz.com.
For a list of approved products, consult an
authorized Mercedes-Benz Center. Comply
with the instructions for use on the product
label.
Do not mix other fuel additives with fuel. This
causes unnecessary costs and could damage
the engine.
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.
! Only use commercially available vehicular
ULTRA-LOW SULFUR DIESEL FUEL (ULSD,
15 ppm maximum sulfur content) that meets the ASTM D975 standard. If you do
not
refuel with ULSD, you

may damage the
BlueTEC exhaust gas aftertreatment
system of the vehicle.
! Do not use gasoline to refuel vehicles with
a diesel engine. Do not mix diesel fuel with
gasoline, kerosene or paraffin. This may
otherwise result in damage to the fuel
system and engine.
You will usually find information about the fuel
grade on the pump. If you cannot find the
label on the pump, ask the staff for
assistance.
i For further information, consult a
qualified specialist workshop or on the
Internet at http://www.mbusa.com (USA
only).
Information on refueling (Y page 154).
Bio-diesel - FAME (fatty acid methyl ester)
Mercedes-Benz USA approves the use of bio-
diesel B5 for all BlueTEC diesel engines. The
concentration of bio-diesel in the ULSD may
not exceed 5% by volume.
Pure bio-diesel and diesel fuel with a higher
percentage of bio-diesel, such as B20, can
damage the engine and the fuel system. For
this reason, they are not approved.
For more information, consult the gas station
staff. The bio-diesel B5 label on the gasoline
pump must clearly state that the standard for
ULSD has been fulfilled. If the label is not
clear, do not refuel the vehicle.
Do not refuel your vehicle with fuels unless
they have been approved by Mercedes-Benz.
Information on refueling (Y page 155).
Low outside temperatures
i Diesel fuel with improved cold flow
properties is available during the winter
months. Further information about fuel
properties can be obtained from oil
companies, e.g. at gas stations. 368
Service products and filling capacities
Technical data

Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot
components in the engine compartment, it
may ignite. There is a risk of fire and injury.
Let the engine cool down before you add
antifreeze. 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 Service Products, MB Specifications for
Service Products 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.
When handling coolant, observe the
important safety notes on service products
(Y page 365).
The coolant is a mixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
R 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/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, heat
will not be dissipated as effectively.
If the vehicle has lost coolant, add equal
amounts of water and antifreeze/corrosion
inhibitor.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in
accordance with MB Specifications for
Service Products 310.1.
The coolant is checked with every
maintenance interval at a qualified specialist
workshop.
i When the vehicle is first delivered, it is
filled with a coolant mixture that ensures
adequate antifreeze and corrosion
protection.
Filling capacities Model Capacity
GLK 250 BlueTEC
approx. 10.6 US qt
(10.0 l) GLK 350
BlueEFFICIENCY
GLK 350 4MATIC
BlueEFFICIENCY
approx. 8.9 US qt
(8.4 l) i
Use MB 325.0 or MB 326.0 corrosion
inhibitor/antifreeze. Service products and filling capacities
371
Technical data Z