
For more information on engine oil, see
“Fuels, coolants, lubricants etc.”
(Y page 368).
For information on messages in the
multifunction display concerning engine oil,
see the “Practical hints” section
(Y page 308).
Adding engine oil
! Only use approved engine oils and oil
filters required for vehicles with
Maintenance System. For a listing of
approved engine oils and oil filters, contact
an authorized Mercedes-Benz Center or
visit www.mbusa.com (USA only).
The following will result in engine or
emission control system damage not
covered by the Mercedes-Benz Limited
Warranty:
RUsing engine oils and oil filters of
specification other than those expressly
required for the Maintenance System.
RChanging of oil and oil filter at change
intervals longer than those called for by
the Maintenance System.
RUsing any oil additives.
Example illustration: GL 450 (GL 350 BlueTEC,GL 550 similar)
XUnscrew filler cap : from filler neck.XAdd engine oil as required. Be careful not
to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
! Excess oil must be siphoned or drained
off. It could cause damage to the engine
and emission control system not covered
by the Mercedes-Benz Limited Warranty.
XScrew filler cap : back on filler neck.
For more information on engine oil, see the
“Technical data” section (Y page 368) and
(Y page 370).
Transmission fluid level
The transmission fluid level does not need to
be checked. If you notice transmission fluid
loss or gearshifting malfunctions, have an
authorized Mercedes-Benz Center check the
transmission.
Coolant level
The engine coolant is a mixture of water and
anticorrosion/antifreeze.
When checking the coolant level, the vehicle
must be parked on level ground, and the
coolant temperature must be below 158‡
(70†).
GWarning!
In order to avoid any potentially serious burns:
RUse extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system, or
if the coolant temperature display indicates
that the coolant is overheated.
RDo not remove the cap on the coolant
expansion tank if the coolant temperature
is above 158‡ (70†). Allow the engine to
cool down before removing the cap. The
coolant expansion tank contains hot fluid
and is under pressure.
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RUsing a rag, slowly open the cap
approximately 1/2 turn to relieve excess
pressure. If opened immediately, scalding
hot fluid and steam will be blown out under
pressure.
RDo not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts.
XUsing a rag, slowly open cap ;
approximately 1/2 turn to relieve excess
pressure.
XContinue turning cap ; counterclockwise
and remove it.
The coolant level is correct if the level
Rfor cold coolant: reaches marking
bar : in coolant expansion tank =
Rfor warm coolant: is approximately 0.6 in
(1.5 cm) higher
XAdd coolant as required.XScrew cap ; back on and tighten it.
For more information on coolant, see the
“Technical data” section (Y page 369) and
(Y page 373).
Washer system and headlamp
cleaning system
GWarning!
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on hot engine parts, because it may
ignite and burn. You could be seriously
burned.
! Always use washer solvent/antifreeze
where temperatures may fall below
freezing point. Failure to do so could result
in damage to the washer system/fluid
reservoir.
! Only use washer fluid which is suitable for
plastic lenses. Improper washer fluid can
damage the plastic lenses of the
headlamps.
! Do not use distilled or deionized water in
the washer fluid reservoir. Otherwise, the
washer fluid level sensor could be
damaged.
Fluid for the washer system, rear window
washer system, and the headlamp cleaning
system is supplied from the washer fluid
reservoir.
During all seasons, use MB Windshield
Washer Concentrate “MB SummerFit”. Mix it
with water or premixed washer solvent/
antifreeze depending on the ambient
temperature (Y page 375).
XOpening washer fluid reservoir: Pull tab
of cap : upwards.
XRefill the washer fluid reservoir.XClosing washer fluid reservoir: Press
cap : onto filler hole until it engages.
232Engine compartmentOperation
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practice turning, stopping and backing up
in an area which is free of traffic.
R Before you start driving check the
- trailer hitch
- break-away switch
- safety chains
- electrical connections
- lighting
- tires
R Adjust the mirrors ( Y page 94) to permit
unobstructed view beyond rear of trailer.
R If the trailer has electric brakes, start your
vehicle and trailer moving slowly, and then
apply only the trailer brake controller by
hand to make sure the brakes are working
properly.
R Always secure items in the trailer to
prevent load shifts while driving.
R When towing a trailer, check occasionally
to make sure the load is secure, and that
trailer lighting and brakes (if so equipped)
are functioning properly.
R Take into consideration that when towing a
trailer, the handling characteristics are
different and less stable from those when
operating the vehicle without a trailer.
It is important to avoid sudden maneuvers.
R The vehicle and trailer combination is
heavier, and therefore limited in
acceleration and climbing ability, and has a
larger braking distance.
It is more prone to reacting to cross wind
gusts, and requires more sensitive steering
input.
R If possible, do not brake abruptly, but
rather engage the brake slightly at first to
permit the trailer to activate its brake. Then
increase the braking force.
! If the trailer should begin to sway, reduce
the vehicle’s speed immediately.Do not attempt to straighten out the tow
vehicle and trailer by increasing the speed.
R If the transmission shifts between gears on
inclines repeatedly, shift to a lower gear
range manually ( Y page 118). Select 4, 3 ,
2 or 1.
A lower gear and reduction of speed
reduces the chance of engine overloading
and/or overheating.
R On very steep inclines, not manageable
with automatic transmission in gear range
1 , switch on off-road driving program
( Y page 158) or LOW RANGE mode
( Y page 120).
R When going down an incline, shift into a
lower gear and use the engine’s braking
effect.
Avoid riding the brakes, thus overheating
the vehicle and trailer brakes (if so
equipped).
R If the engine coolant rises to an extremely
high temperature when the air conditioning
is on, turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows, switching
the climate control fan speed to high and
setting the temperature control to the
maximum.
R During a passing maneuver extreme care
must be exercised since your vehicle with
a trailer will require additional passing
distance ahead than when driving without
a trailer.
Because your vehicle and trailer is longer
than your vehicle alone, you will also need
to go much farther ahead of the passed
vehicle before you can return to your lane.
Decoupling a trailer GWarning!
While you are coupling or decoupling a trailer,
make sure nobody locks or unlocks the
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EngineDisplay messagesPossible causes/consequences and M Solutions+Top Up
Coolant
See
Operator’s
ManualThe coolant level is too low.XAdd coolant ( Y page 231).XIf you have to add coolant frequently, have the cooling
system checked at an authorized Mercedes-Benz Center.GWarning!
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! Do not ignore the low engine coolant level warning. Extended driving with the message
and symbol displayed may cause serious engine damage not covered by the Mercedes-Benz
Limited Warranty.
Do not drive without sufficient amount of coolant in the cooling system. The engine will
overheat causing major engine damage.
Display messagesPossible causes/consequences and M Solutions?Coolant
Stop car,
switch
engine
off.The coolant is too hot.XStop the vehicle immediately as soon as it is safe to do so.XTurn off the engine immediately.XEngage the parking brake.XOnly start the engine again after the message disappears.
You could otherwise damage the engine.XObserve the coolant temperature in the multifunction
display.XIf the temperature rises again: Contact an authorized
Mercedes-Benz Center immediately.
During severe operation conditions and stop-and-go city
traffic, the coolant temperature may rise close to 248‡
(120†).
GWarning!
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.
306Vehicle status messages in the multifunction displayPractical hints
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! The engine should not be operated with the coolant temperature above 248‡ (120†).
Doing so may cause serious damage which is not covered by the Mercedes-Benz Limited
Warranty.Display messagesPossible causes/consequences and M Solutions?Coolant
Stop car,
switch
engine
off.The poly-V-belt could be broken.XStop the vehicle immediately as soon as it is safe to do so.XTurn off the engine immediately.XCheck the poly-V-belt.XIf it is broken: Do not continue to drive. Otherwise the
engine will overheat due to an inoperative water pump
which may result in damage to the engine. Contact an
authorized Mercedes-Benz Center.XIf it is intact: Do not continue to drive the vehicle with this
message displayed. Doing so could result in serious engine
damage that is not covered by the Mercedes-Benz Limited
Warranty.XObserve the coolant temperature in the multifunction
display.XDrive to the nearest authorized Mercedes-Benz Center
immediately.?The radiator cooling fan is malfunctioning.XObserve the coolant temperature in the multifunction
display.
If the coolant temperature is below 248‡ (120†), you may
continue driving to an authorized Mercedes-Benz Center.XAvoid placing heavy loads on the engine (e.g. by driving
uphill) as well as stop-and-go traffic.XHave the fan replaced as soon as possible.Vehicle status messages in the multifunction display307Practical hintsX164_AKB; 5; 31, en-USd2ureepe,Version: 2.11.8.12009-09-11T12:30:16+02:00 - Seite 307Z

ModelCapacityFuels, coolants,
lubricants, etc.
Air
conditioning
system
All models—R134a refrigerant
and special
PAG lubricant oil
(never R 12)
Washer system
and headlamp
cleaning
system
All models7.6 US qt (7.2 l)MB Windshield
Washer
Concentrate44
(Y page 375)
Washer fluid mixing
ratio (Y page 375)
Approved engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for our
service intervals. Therefore, only use
approved engine oils and oil filters required
for vehicles with the Maintenance System.
For a listing of approved engine oils and oil
filters, contact an authorized Mercedes-Benz
Center or visit www.mbusa.com (USA only).
! Using engine oils and oil filters of a
specification other than those expressly
required for the Maintenance System, or
changing of oil and oil filter at change
intervals longer than those called for by the
Maintenance System will result in engine or
emission control system damage not
covered by the Mercedes-Benz Limited
Warranty.
Please follow Maintenance System
recommendations for scheduled oil
changes. Failure to do so will result in
engine or emission control system damage
not covered by the Mercedes-Benz Limited
Warranty.
Mercedes-Benz recommends MOBIL OIL.
Use the table below to determine the
MB sheet number.
ModelEngine,
type
MB sheet
number
GL 350 BlueTEC642229.51GL 450273229.5GL 550273229.5
iMB sheet numbers are printed on the
outside of oil containers.
Viscosity grades for engine oils
Using the chart below, select oil viscosity
according to the lowest air temperature
expected before the next oil change.
44Mixed with water or commercially available premixed washer solvent/antifreeze.370Fuels, coolants, lubricants, etc.Technical data
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vehicles are not covered by the Mercedes-
Benz Limited Warranty or by any pre-owned
or Extended Limited Warranties.
AdBlue ®
AdBlue ®
is a non-flammable, non-toxic,
colorless and odorless, water-soluble liquid.
! Only use AdBlue ®
complying with
ISO 22241. Do not blend with additives.
! Rinse surfaces that have come into
contact with AdBlue ®
, or remove AdBlue ®
with a moist cloth and cold water
immediately. If AdBlue ®
has crystallized
already, use cold water and a sponge.
AdBlue ®
residues will crystallize and soil
the affected surfaces.
High ambient temperatures
If AdBlue ®
in the reservoir heats up to above
122‡ (50†) for a long period of time, for
example due to direct sunlight, ammonia gas
vapors may escape when opening the
AdBlue ®
tank.
GWarning!
When opening the filler cap of the AdBlue ®
tank ammonia gas vapors may escape. Refill
AdBlue ®
in a well ventilated area only.
Ammonia gas vapors have a pungent odor and
are particularly irritating for your skin,
mucous membranes, and eyes. Inhaling
ammonia gas vapors will cause burning eyes,
nose, and throat, as well as coughing and
watering eyes.
Low ambient temperatures
AdBlue ®
freezes at a temperature of
approximately 12‡ (-11†). Your vehicle is
factory equipped with an AdBlue ®
preheating
system. The vehicle can thus be operated at
temperatures below 12‡ (-11†).
Special additives
! Only use AdBlue ®
complying with
ISO 22241. Do not add additives to
AdBlue ®
and do not dilute AdBlue ®
with
water. Otherwise, the BlueTEC exhaust gas
aftertreatment system could be damaged.
Damage caused by using additives or
diluting with water are not covered by the
Mercedes-Benz Limited Warranty.
Purity
The purity of AdBlue ®
is of particular
importance for avoiding malfunctions in the
exhaust gas aftertreatment.
If AdBlue ®
is pumped out of the tank, e.g.
during repair work, the same liquid must not
be used to refill the tank as its purity is no
longer guaranteed.
! Impurities caused for example by other
service products, cleaning agents, and dust
result in increased emissions,
malfunctions, catalyst damage, or engine
damage.
Coolants
The engine coolant is a mixture of water and
anticorrosion/antifreeze, which provides:
R Corrosion protection
R Freeze protection
R Boiling protection (by increasing the boiling
point)
The cooling system was filled at the factory
with a coolant providing freeze protection to
approximately -35‡ (-37†) and corrosion
protection.
! Add premixed coolant solution only.
Adding water and MB 325.0 Anticorrosion/
Antifreeze separately from each other,
could cause engine damage not covered by
the Mercedes-Benz Limited Warranty.
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If the antifreeze mixture is effective to -35‡
(-37† ), the boiling point of the coolant in the
pressurized cooling system is reached at
approximately 266‡ (130†).
The coolant solution must be used year round
to provide the necessary corrosion protection
and increase boil-over protection. Refer to
the Maintenance Booklet for replacement
interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable if
MB 325.0 Anticorrosion/Antifreeze solution
or other Mercedes-Benz approved products
of equal specification are used to renew the
coolant concentration or bring it back up to
the proper level.
For information on other Mercedes-Benz
approved products of equal specification,
contact an authorized Mercedes-Benz Center
or visit www.mbusa.com (USA only).
To provide important corrosion protection,
the solution must be at least 50%
anticorrosion/antifreeze (equivalent to
freeze protection to approximately -35‡
[-37†]).
If you use a solution that is more than 55%
anticorrosion/antifreeze (freeze protection
to approximately -49‡ [-45†]), the engine
temperature will increase due to the lower
heat transfer capability of the solution.
Therefore, do not use more than this amount
of anticorrosion/antifreeze.If the coolant level is low, water and MB 325.0
Anticorrosion/Antifreeze should be used to
bring it up to the proper level (have cooling
system checked for signs of leakage). Please
make sure the mixture is in accordance with
label instructions.
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water.
If you are not sure about the water quality,
contact an authorized Mercedes-Benz
Center.
Anticorrosion/antifreeze
Your vehicle contains a number of aluminum
parts. The use of aluminum components in
motor vehicle engines necessitates that
anticorrosion/antifreeze coolant used in
such engines be specifically formulated to
protect the aluminum parts. Failure to use
such anticorrosion/antifreeze coolant will
result in a significantly shortened service life.
Therefore, the following product is strongly
recommended for use in your vehicle:
MB 325.0 Anticorrosion/Antifreeze agent.
Before the start of the winter season (or once
a year in hot southern regions), you should
have the anticorrosion/antifreeze
concentration checked.
The coolant is also regularly checked each
time you bring your vehicle to an authorized
Mercedes-Benz Center for service.
ModelApproximate freeze protection-35‡ (-37†)-49‡ (-45†)Cooling systemGL 350 BlueTEC5.0 US qt (4.75 l)5.5 US qt (5.2 l)GL 450
GL 5506.3 US qt (6.0 l)7.0 US qt (6.6 l)374Fuels, coolants, lubricants, etc.Technical data
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