2015 MERCEDES-BENZ G-Class engine overheat

Displays and operation
Instrument cluster
Instrument cluster: miles
:
Speedometer with segments (Y page 198)
; Multifunction display (Y page 199)
= Tachometer (Y page 198)
? Coolant temperature (Y page 197)
A Fuel gage
B Instrument cluster lighting (Y page 197)Instrument cluster lighting
The brightness control knob is located on the bottom left of the instrument cluster
(Y page 197).
X Turn the brightness control knob clockwise
or counter-clockwise.
If the light switch is set to Ã,Tor
L, the brightness is dependent upon
the brightness of the ambient light.
i The light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated. Displaying the coolant temperature
G
WARNING
Driving when your engine is overheated can
cause some fluids which may have leaked into the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until
the engine has cooled down.
! A display message is shown if the coolant
temperature is too high. Displays and ope
ration
197On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions ?
Coolant Too Hot Coolant Too Hot
Stop Vehicle Stop Vehicle
Switch Engine Off Switch 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 150).
X Leave the vehicle and keep a safe distance from the vehicle 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 †). Other-
wise, 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 †). The poly-V-belt may have torn.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Check the poly-V-belt.
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 Wait until the display message disappears before restarting the
engine. Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X Visit a qualified specialist workshop. 222
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions # 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 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. 4
Check Engine Oil Check Engine Oil
At Next Refueling 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 275).
X If necessary, add engine oil (Y page 277).
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://
www.mbusa.com (USA only). 4
Engine Oil Level Engine Oil Level
Low Stop Vehicle Low Stop Vehicle
Switch Engine Off Switch Engine Off The engine oil level is too low. There is a risk of engine damage.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Add engine oil (Y page 277) and check the oil level
(Y page 275). Display
messages
223On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunc-
tioning.
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 Apply 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 add coolant, observing the warning
notes (Y page 278).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
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 coolant temperature is
below 248 ‡(120 †). Otherwise, the engine could 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 248 ‡ (120 †). The air-
flow 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. 244
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment 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 special-
ist workshops: (Y page 24). 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
Certain components in the engine compart-
ment may be very hot, e.g. the drive system
and radiator. Working in the engine compart-
ment poses a risk of injury.
If possible, let the drive system cool down and only touch the components described in the
following. 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. G
WARNING
The ignition system and the fuel injection sys- tem work under high voltage. If you touch
components which are under voltage, you
could get an electric shock. There is a risk of
injury.
Never touch components of the ignition sys-
tem or fuel injection system when the ignition is switched on. 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
When the hood is open and the windshield
wipers are set in motion, you can be injured by the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
Do not touch the following when the ignition
is switched on: R ignition coils
R spark plug connectors
R test socket 274
Engine compartmentMaintenance and care

Warning symbol
:advises you about:
R possible dangers
R having service work carried out at a quali-
fied specialist workshop
Filling capacities Missing values were not available at time of
going to print. AMG vehicles Capacity
Refrigerant
PAG oil
All other models Capacity
Refrigerant
PAG oil
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 337).
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 work-
shop or on the Internet at
http://bevo.mercedes-benz.com. 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 com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. 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 BeVo 310.1, e.g.
on the Internet at
http://bevo.mercedes-benz.com. Or con-
tact 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 337). 342
Service products and filling capacitiesTechnical data

The coolant is a mixture of water and anti-
freeze/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 cool-
ant in the pressurized system is approx-
imately 266 ‡ (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 -35 ‡ (-37 †).
R no t exceed 55% (antifreeze protection
down to -49 ‡ [-45 †]). Otherwise, heat
will no t be dissipated as effectively.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor in accordance with MB
Specifications for Service Products 310.1.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion.
i The coolant is checked with every main-
tenance interval at a qualified specialist
workshop.
The engine cooling system is filled with cool-
ant at the factory which contains antifreeze/
corrosion inhibitor that ensures protection
down to approximately -35 ‡ (-37 †).
Your vehicle has a range of aluminum com-
ponen ts. Aluminum components in the
engine make it necessary to use antifreeze/
corrosion inhibitor that has been specifically
formulated to protect the aluminum parts.
Failure to use such anticorrosion/antifreeze
coolant will result in a significantly shortened
service life.
The coolant must be used throughout the year
in order to maintain the necessary corrosion
protection and to provide protection from
overheating. In the Maintenance Booklet, you can find information on the intervals for
renewal.
The renewal interval is determined by the
coolant type and the engine cooling system
design. The renewal interval in the Mainte-
nance Booklet is only valid if the coolant is
renewed or added to with Mercedes-Benz
approved products. Therefore, only use MB
326.0 antifreeze/corrosion inhibitor or
another Mercedes-Benz approved product of the same specification.
Information on other products with the same
specifications that are approved by
Mercedes-Benz can be obtained at an author- ized Mercedes-Benz Center or on the Internet at http://bevo.mercedes-benz.com.
If the coolant level is too low, MB 325.0 anti-
freeze/corrosion inhibitor should be added.
Have the engine cooling system checked for
possible leaks.
Capacity Model Capacity
G 550
Approx. 11.1 US qt
(10.5 l)
G 63 AMG
Approx. 14.6 US qt
(13.8 l)
Low-temperature
circuit: approx-
imately 3.1 US qt
(2.9 l)
i
Use MB 325.0 or MB 326.0 antifreeze/
corrosion inhibitor. Windshield/headlamp cleaning sys-
tem
Important safety notes G
WARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo- Service products and filling capacities
343Technical data
Z