cooling MERCEDES-BENZ G-CLASS SUV 2012 User Guide

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
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 mal-
functioning.
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 Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Engage the parking brake.
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 293).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 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.
Never drive with an overheated engine. Driving when your engine
is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
Steam from an overheated engine can cause serious burns which
can occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 163).Warning and indicator lamps in the instrument cluster
261On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
X
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 293).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain and stop-start driving. Driving systems
Problem Possible causes/consequences and
M Solutions
·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. The distance to the vehicle in front is too small for the speed
selected.
X
Increase the distance. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion.
Aw arning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X
Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on DISTRONIC PLUS (Y page 182).262
Warning and indicator lamps in the instrument clusterOn-board computer and displays

X
If the engine is at normal operating tem-
perature: repeat the measuremen tafter
about five minutes.
X If the engine is not at normal operating
temperature: (e.g. if the engine was only
started briefly) repeat the measurement
after about 30 minutes.
If the Engine oil level Not when engine on message appears:
X Switch off the engine.
X If the engine is at normal operating tem-
perature: wait about five minutes before
carrying out the measurement.
X If the engine is not at normal operating
temperature: e.g. if the engine was only
started briefly, wait approximately
30 minutes before carrying out the meas-
urement.
i If you wish to cancel the measurement,
press the *or& button on the mul-
tifunction steering wheel.
Adding engine oil H
Environmental note
When topping up the oil, take care not to spill
any. If oil enters the soil or waterways, it is
harmful to the environment.
! Do not add too much oil .Ifthe 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 con-
verter. Have excess oil siphoned off. Engine oil cap (example:
G 65 AMG) X
Turn cap :anti-clockwise and remove it.
X Top up with the amount of oil required.
Observe the specifications in the on-board
computer when doing so or fill carefully to the
maximum mark on the oil dipstick.
For further information on engine oil, see
(Y page 345).
i The difference between the minimum
mark and the maximum mark on the oil
dipstick is approximately 2litres.
X Replace cap :on the filler neck and
tighten clockwise.
Make sure that the cap locks securely into
place. Other service products
Checking the coolant level G
WARNING
The cooling system is pressurised. Therefore,
only unscrew the cap once the engine has
cooled down. The coolan ttemperature dis-
play must be less than 70 †. Otherwise, you
could be scalded if hot coolant escapes. X
Park the vehicle on a level surface.
Only chec kthe coolant level if the vehicle
is on a level surface and the engine has
cooled down.
X Turn the key to position 2(Ypage 143) in
the ignition lock. Engine compartment
293Maintenance and care Z

If the boiling point of the brake fluid is too low,
vapourp ockets 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.com.
i Have the brake fluid regularly replaced 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 antifreez eprotection. 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-corrosio nprotection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant will be around 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 downto
approximately -3 7†.
R not exceed 55% (antifreeze protection
down to -45 †). Hea twill otherwise not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor-
rosio ninhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibito rin
accordance with MB Specifications for
Service Products 310.1.
The coolan tis checked at every maintenance
interval at a qualified specialist workshop.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion. Washer fluid
Important safety notes G
WARNING
Windscreen washer concentrate is highly
flammable. If it comes into contact with hot Service products and capacities
347Technical data
Z

Trailer tow hitch
Mounting dimensions
G
WARNING
Only have a trailer tow hitch retrofitted at a
qualified specialis tworkshop.
! If you have a trailer tow hitch retrofitted,
changes to the engine cooling system may
be necessary, depending on the vehicle
type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chas-
sis frame. Example: anchorage points for the trailer tow hitch
:
Anchorage points
; Overhang dimension
For trailer tow hitches fitted at the factory, the
overhang dimension including protective cov-
ering is 895 mm. Trailer loads
G-Class long-wheelbase
version (all models)
Permissible trailer load,
unbraked
750 kg
Permissible trailer load,
braked (at a minimum
gradient-climbing capa-
bility of 12% from
astand-
still) 3500 kg
Maximum drawbar nose-
weight (the drawbar
noseweight is no tinclu-
ded in the trailer load) 140 kg
Permissible rear axle
load when towing
atrailer 1900 kg
Maximum gross vehicle
weight when towing a
trailer
6700 kg
G-Class Cabriolet
Permissible trailer load,
unbraked
750 kg
Permissible trailer load,
braked (at a minimum
gradient-climbing capa-
bility of 12 %from astand-
still) 2850 kg
Maximum drawbar nose-
weight (the drawbar
noseweight is no tinclu-
ded in the trailer load) 115 kg
Permissible rear axle
load when towing a
trailer (the drawbar nose-
weight is not included in
the towing weight) 1800 kg
Maximum gross vehicle
weight when towing a
trailer 5700 kg350
Trailer tow hitchTechnical data