2014 MERCEDES-BENZ GLK-CLASS SUV coolant temperature

Problem Possible causes/consequences and
M
MSolutions ?
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gauge is
at the start of the scale.
The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X
Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.
X Secure the vehicle against rolling away (Y page 164).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
269On-board computer and displays Z

Problem Possible causes/consequences and
M
MSolutions ?
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 164).
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 304). 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. ?
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 164).
X Wait until the engine has cooled down. 270
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M
MSolutions 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 304). 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. Driving systems
Problem Possible causes/consequences and
M MSolutions ·
The red distance
warning lamp lights up
while the vehicle is in
motion.
G
WARNING
The distance to the vehicle in front is too small for the speed
selected.
There is a risk of an accident.
X Increase the distance. ·
The red distance
warning lamp lights up
while the vehicle is in
motion. A warning tone
also sounds.
G
WARNING
You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
There is a risk of an accident.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC PLUS (Y page 175) and
PRE-SAFE ®
Brake (Y page 72). Warning and indicator lamps in the instrument cluster
271On-board computer and displays Z

approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
center.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R replacing engine oil and oil filters after
the interval for replacement specified by
the service system has been exceeded
R using engine oil additives.
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic
converter. Have excess oil siphoned off. Example: engine oil cap
X
Turn cap :counter-clockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark
on the oil dipstick, add 1.1 US qt (1.0 l) of
engine oil.
X Replace cap :on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil
dipstick (Y page 303).
Further information on engine oil
(Y page 371). Checking and adding other service
products
Checking coolant level 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
The engine cooling system is pressurized,
particularly when the engine is warm. When
opening the cap, you could be scalded by hot
coolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape.
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 2in the
ignition lock (Y page 145).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 145).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †). 304
Engine compartmentMaintenance and care

Filling capacities
The following values refer to an oil change
including the oil filter.
Model Capacity
All models
6.9 US qt
(6.5 l) Additives
!
Do not use any additives in the engine oil.
This could damage the engine.
Engine oil viscosity Viscosity describes the flow characteristics
of a fluid. If an engine oil has a high viscosity,
this means that it is thick; a low viscosity
means that it is thin.
Select an engine oil with an SAE classification
(viscosity) suitable for the prevailing outside
temperatures. The table shows you which
SAE classifications are to be used. The low-
temperature characteristics of engine oils
can deteriorate significantly, e.g. as a result
of aging, soot and fuel deposits. It is therefore
strongly recommended that you carry out
regular oil changes using an approved engine
oil with the appropriate SAE classification. Brake fluid
G
WARNING
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
important safety notes on service products
(Y page 367).
The brake fluid change intervals can be found
in the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz according to 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.
i Have the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet. 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 372
Service products and filling capacitiesTechnical data

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.
i Have the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet.
Comply with the important safety precautions
for service products when handling coolant
(Y page 367).
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.
i When the vehicle is first delivered, it is
filled with a coolant mixture that ensures adequate antifreeze and corrosion
protection.
i The coolant is checked with every
maintenance interval at a qualified
specialist workshop.
Filling capacities Model Capacity
GLK 350
GLK 350 4MATIC
Approx. 8.9 US qt
(8.4 l) GLK 250 BlueTEC
Approx. 10.4 US qt
(9.8 l) i
Use MB 325.0 or MB 326.0 corrosion
inhibitor/antifreeze. Windshield washer system
Important safety notes G
WARNING
Windshield washer concentrate is highly
flammable. If it comes into contact with hot
engine components or the exhaust system it
could ignite. There is a risk of fire and injury.
Make sure that no windshield washer
concentrate 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 damage the plastic lenses of the
headlamps.
! Do not add distilled or de-ionized water to
the washer fluid container. Otherwise, the
level sensor may be damaged.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
When handling washer fluid, observe the
important safety notes on service products
(Y page 367). Service products and filling capacities
373Technical data Z