overheating MERCEDES-BENZ GLK SUV 2012 Owners Manual

i
The ECO display summarises the driving
characteristics from the start of the journey
to its completion. Therefore, there are
dynamic changes in the bars at the start of
a journey. During a prolonged driving time,
these changes are smaller. For dynamic
changes, perform a manual reset.
For further information on the ECO display,
see (Y page 231). Short journeys
! Vehicles with a diesel particle filter: if
the vehicle is mostly driven for short dis-
tances, it is possible that malfunctions may
occur during the automatic cleaning of the
diesel particle filter. This may lead to fuel
collecting in the engine oil and cause
engine failure. Therefore, if you frequently
drive short distances, you should take a 20
minute trip on a motorway or rural road at
least every 500km. Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients On long and steep downhill gradients, you
must select shift range
1,2or 3in good time.
Take particular note of this when driving a
laden vehicle and when towing a trailer.
i This also applies if you have activated
cruise control or SPEEDTRONIC. This will use the braking effect of the engine,
so less braking will be required to prevent the
vehicle from gaining speed. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
Heavy and light loads
G
WARNING
The braking system can overheat if you leave
your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There
is a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately.
Drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
If the brakes have been used only moderately,
you should occasionally test their effective-
ness. To do this, brake more firmly from a
higher speed. This improves the grip of the
brakes.
Wet road surfaces If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm
up the brake discs, thereby drying them more Driving tips
167Driving and parking Z

R
Observe the warnings for off-road driving
(Y page 170).
R Drive slowly.
R Accelerate gently and make sure that the
wheels are gripping.
R Avoid high engine speeds, except when
driving on sandy and muddy routes with
high driving resistance.
R Select a shift range appropriate to the gra-
dient.
R Before tackling steep downhill gradients,
select shift range 1.
Maximum gradient-climbing capability On good road surfaces, 70% of the maximum
gradient-climbing capability is available.
i If the load on the front axle is reduced
when pulling away on a steep uphill slope,
the front wheels have a tendency to spin.
4ETS recognises this and brakes the
wheels accordingly. The rear wheel torque
is increased and it is easier to pull away.
Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator immedi-
ately before reaching the brow of the hill.
Make use of the vehicle's own impetus to
travel over the brow.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R the vehicle from travelling too quickly down
the other side.
Driving downhill R
Drive slowly.
R Do not drive at an angle down steep
inclines. Steer into the line of fall and drive
with the front wheels aligned straight. Oth-
erwise, the vehicle could slip sideways, tip
and overturn. R
Before tackling steep downhill gradients,
select shift range 1.
R Activate DSR. If this is not sufficient, brake
gently. When doing so, make sure that the
vehicle is facing in the direction of the line
of fall.
R Check that the brakes are working normally
after a long downhill stretch.
i Off-road ABS is activated when the off-
road drive program is selected.
At speeds below 30 km/h, the front wheels
lock cyclically during braking. The digging-
in effect achieved in the process reduces
the stopping distance when driving off-
road. The steerability of the vehicle is con-
siderably reduced if the wheels lock. Driving systems
Cruise control
Important safety notes Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. You must
select a low gear in good time on long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer. On vehicles
with automatic transmission, select shift
range
1,2or 3. By doing so, you will make
use of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a
steady speed for a prolonged period. You can
store any road speed above 30 km/h. Driving systems
173Driving and parking Z

SPEEDTRONIC
Important safety notes G
WARNING
Never depress the brake pedal continuously
while the vehicle is in motion, e.g. never cause
the brakes to rub by applying constant slight
pedal pressure. This causes the brake system
to overheat, increases the braking distance
and can lead to the brakes failing completely. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. G
WARNING
SPEEDTRONIC is only an aid designed to
assist driving. You are responsible for the
vehicle's speed and for braking in good time.
SPEEDTRONIC brakes automatically so that
you do not exceed the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer, you must
shift to a lower gear in good time or select
shift range 1,2or 3on vehicles with auto-
matic transmission. By doing so, you will
make use of the braking effect of the engine.
This relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly. If you need additional
braking, depress the brake pedal repeatedly
rather than continuously.
You can set a variable or permanent limit
speed:
R variable for speed limits, e.g. in built-up
areas
R permanent for long-term speed restric-
tions, e.g. when driving with winter tyres
fitted (Y page 178)
i The speed indicated in the speedometer
may differ slightly from the limit speed
stored. Variable SPEEDTRONIC General notes
With the cruise control lever, you can operate
cruise control or DISTRONIC PLUS and vari-
able SPEEDTRONIC.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec-
ted:
R LIM indicator lamp off: cruise control or
DISTRONIC PLUS is selected.
R LIM indicator lamp on: variable SPEED-
TRONIC is selected.
You can use the cruise control lever to limit
the speed to any speed above 30 km/hw hile
the engine is running. :
To store the current speed or a higher
speed
; LIM indicator lamp
= To store the current speed and call up the
last stored speed
? To store the current speed or a lower
speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate variable SPEEDTRONIC
Selecting variable SPEEDTRONIC
X Check whether LIM indicator lamp ;is on.
If it is on, variable SPEEDTRONIC is already
selected. 176
Driving systemsDriving and parking

Permanent SPEEDTRONIC
You can use the on-board computer to limit
the speed permanently to a value between
160 km/h(e.g. for driving on winter tyres) and
the maximum speed (Y page 241).
Shortly before the stored speed is reached, it
appears in the multifunction display.
Permanent SPEEDTRONIC remains active,
even if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed,
even if you depress the accelerator pedal
beyond the pressure point (kickdown). DISTRONIC PLUS
Important safety notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. DIS-
TRONIC PLUS brakes automatically so that
the set speed is not exceeded.
On long and steep downhill gradients, espe-
cially if the vehicle is laden or towing a trailer,
you must select shift range 1,2or 3in good
time. By doing so, you will make use of the
braking effect of the engine. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
If DISTRONIC PLUS detects a slower-moving
vehicle in front, your vehicle is braked in order
to maintain the preset distance to the vehicle
in front. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. G
WARNING
DISTRONIC PLUS is only an aid designed to
assist driving. The driver remains fully respon-
sible for the vehicle's distance from other vehicles, the vehicle's speed and for braking
in good time.
DISTRONIC PLUS does not react in particular
to:
R pedestrians
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
DISTRONIC PLUS may not detect narrow vehi-
cles driving in front, e.g. motorcycles, or vehi-
cles driving on a different line. Therefore,
always pay attention to traffic conditions even
when DISTRONIC PLUS is activated. Other-
wise, you may fail to recognise dangers in
time, cause an accident and injure yourself
and others. G
WARNING
DISTRONIC PLUS cannot take account of road
and traffic conditions. If DISTRONIC does not
recognise or no longer recognises the vehicle
in front, do not activate DISTRONIC or, if it is
already active, deactivate it. This is especially
the case:
R before corners
R on filter lanes
R when changing to a lane with faster moving
traffic
R in complex driving situations or where lanes
are diverted, e.g. at roadworks on a motor-
way
DISTRONIC PLUS otherwise maintains the
current speed set by you or accelerates up to
the set speed.
DISTRONIC PLUS cannot take account of
weather conditions. Deactivate, or do not
activate, DISTRONIC PLUS:
R if the roads are slippery, snow-covered or
icy. The wheels could lose their grip when
braking or accelerating. The vehicle could
start to skid.
R if the sensors are dirty or there is poor vis-
ibility, e.g. due to snow, rain or fog. Dis-
tance control may be impaired. 178
Driving systemsDriving and parking

The maximum noseweight of the trailer draw-
bar on the ball coupling is 80 kg. However,
the actual noseweight may not be higher than
the value which is given on the trailer tow
hitch or trailer identification plates. The low-
est weight applies.
! Use a drawbar noseweight as close as
possible to the maximum permissible nose-
weight. Do not use a noseweight of less
than 50kg, otherwise the trailer may come
loose.
Note that the payload and the rear axle load
are reduced by the actual payload.
i The height of the ball coupling changes
with the load of the vehicle. If necessary,
use a trailer with a height-adjustable draw-
bar.
Driving tips i
Observe the notes on ESP ®
trailer stabi-
lisation (Y page 69).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check
the trailer's documents to see what the max-
imum permitted speed is. Observe the legally
prescribed maximum speed in the relevant
country.
For certain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing a trailer. Refer to the "Technical
data" section to find out whether this applies
to your vehicle. If you utilise any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not
exceed a maximum speed of 100 km/h for
reasons concerning the operating permit.
This also applies in countries in which the
permissible maximum speed for vehicle/
trailer combinations is above 100 km/h.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer, and it will
consume more fuel. Change into a lower gear in good time on long
and steep downhill gradients. On vehicles
with automatic transmission, you have to
select shift range
1,2or 3.
i This also applies if you have activated
cruise control or SPEEDTRONIC.
This will use the braking effect of the engine,
so less braking will be required to prevent the
vehicle from gaining speed. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly. If you need additional braking,
depress the brake pedal repeatedly rather
than continuously.
Driving tips R
Maintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine,
and consequently the vehicle's gradient-
climbing capability, decrease with increas-
ing altitude.
If the trailer swings from side to side:
X Do not accelerate.
X Do not countersteer.
X Brake if necessary. Fitting the ball coupling
X Make a note of the ball coupling key num-
ber.
i You can use this number to obtain a
replacement key from a Mercedes-Benz
Service Centre. Towing a trailer
217Driving and parking Z

used. The low-temperature properties of
engine oils can be significantly impaired dur-
ing operation due to, for example, ageing or
soot and fuel accretion. It is therefore
strongly recommended to observe regular oil
changes using an approved engine oil with the
appropriate SAE classification. Brake fluid
G
WARNING
Over a period of time, the brake fluid absorbs
moisture from the air; This lowers its boiling
point.
If the boiling point of the brake fluid is too low,
vapour pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This impairs braking effi-
ciency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change inter-
vals can be found in the Service 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 work-
shop or on the Internet at
http://bevo.mercedes-benz.co m.
i Have the brake fluid renewed regularly at
a qualified specialist workshop. Coolant
Important safety notes G
WARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when han-
dling antifreeze.
If antifreeze comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any antifreeze on hot
engine parts. !
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 Inter-
net 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.
! The engine cooling system is filled with
coolant, which must be renewed after
15 years or after 250,000 kilometres at the
latest.
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operation will be approx-
imately 130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -37 †.
R not exceed 55% (antifreeze protection
down to -45 †). Heat will otherwise not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor-
rosion inhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibitor con-
centrate in accordance with MB Specifica-
tions for Service Products 310.1. Service products and capacities
371Technical data Z