2007 MERCEDES-BENZ G55AMG engine

263 Operation
Driving instructions
Emission control
Certain engine systems serve to keep the
toxic components of the exhaust gases
within permissible limits required by law.
These systems, of course, will function
properly only when maintained strictly
according to factory specifications. Any
adjustments on the engine should,
therefore, be carried out only by qualified
Mercedes-Benz Light Truck Center autho-
rized technicians.
Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly
according to Mercedes-Benz servicing
requirements. For details refer to the
Maintenance Booklet.
Coolant temperature
During severe operating conditions,
e.g. stop-and-go traffic, the coolant tem-
perature may rise close to approximately
248°F (120°C).The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
engine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas
(such as a garage) which are not properly
ventilated. If you think that exhaust gas
fumes are entering the vehicle while driving,
have the cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
iExcessive coolant temperatures trigger a
warning message in the multifunction display
(
page 348).
Warning!G

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 hood. Stay away
from the engine if you see or hear steam
coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.

264 Operation
At the gas station
RefuelingThe fuel filler flap is located on the
right-hand side of the vehicle towards the
rear.
Locking/unlocking the vehicle with the
SmartKey automatically locks/unlocks the
fuel filler flap.
1Fuel filler flap
2Fuel filler capTurn off the engine.
Remove the SmartKey from the starter
switch.
Push on fuel filler flap1 at the
position indicated by the arrow.
Fuel filler flap1 springs open.
Turn fuel filler cap2 to the left and
hold on to it until possible pressure is
released.
Take off fuel filler cap2.
Set fuel filler cap2 in the recess
(indicated by the arrow) on fuel filler
flap1.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.
Warning!G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
injury.
Never allow sparks, flame or smoking
materials near gasoline!
Turn off the engine before refueling.
Whenever you are around gasoline, avoid
inhaling fumes and skin or clothing contact,
extinguish all smoking materials.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging to
your health.
iIn case that the central locking system does
not release the fuel filler flap, or the opening
mechanism is clamping, you can open the fuel
filler flap using an emergency release in the
cargo compartment, see “Fuel filler flap”
(
page 372).
!The fuel filler cap is tethered to the fuel filler
neck. Do not drop the cap. It could damage the
vehicle paint finish.

265 Operation
At the gas station
Only fill your tank until the filler nozzle
unit cuts out – do not top off or
overfill.
Replace fuel filler cap2 by turning it
clockwise until it audibly engages.
Close fuel filler flap1.
You should hear the latch close shut.
Check regularly and before a long trip
For information on quantities and require-
ments of operating agents, see “Fuels,
coolants, lubricants, etc.” (
page 422).
Open the hood (page 267).
G500
1Coolant
2Brake fluid
Warning!G
Overfilling of the fuel tank may create pres-
sure in the system which could cause a gas
discharge. This could cause the gas to spray
back out when removing the fuel pump noz-
zle, which could cause personal injury.
!When refueling the vehicle, make certain
that no gasoline comes into contact with the rear
side marker to prevent damaging the lens.
iMake sure to close the fuel filler flap before
locking your vehicle as the flap locking pin
prevents closing after you have locked the
vehicle.
iLeaving the engine running and the fuel cap
open can cause the? malfunction indicator
lamp (USA only) or the± malfunction indica-
tor lamp (Canada only) comes on.
For more information, see “Practical hints”
(
page 328).
iOnly use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average of
96 RON/86 MON). Information on gasoline
quality can normally be found on the fuel pump.
Please contact gas station personnel in case la-
bels on the pump cannot be found.
For more information on gasoline, see “Premium
unleaded gasoline” (
page 426), refer to the
Factory Approved Service Products pamphlet
(USA only), or contact an authorized
Mercedes-Benz Light Truck Center.

266 Operation
At the gas station
G55AMG
1Coolant
2Brake fluidBrake fluid
Coolant
For normal replenishing, use water
(potable water quality).
For more information, see “Coolant level”
(
page 274) and see “Fuels, coolants, lu-
bricants, etc.” (
page 422).Engine oil level
For more information on engine oil, see
“Engine oil” (
page 269).
Windshield/rear window washer sys-
tem and headlamp cleaning system
For more information on refilling the
washer reservoir, see “Windshield/rear
window washer system and headlamp
cleaning system” (
page 275).
Vehicle lighting
Check function and cleanliness.
For information on replacing light bulbs,
see “Replacing bulbs” (
page 377).
For more information, see “Exterior lamp
switch” (
page 117).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 288).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Light Truck Center
immediately. Do not add brake fluid as this will
not solve the problem.
For more information, see “Practical hints”
(
page 326) and see “Brake fluid”
(
page 425).

267 Operation
Engine compartment
Engine compartment
Hood
Opening
Warning!G
Do not pull the release lever while the vehi-
cle is in motion. Otherwise the hood could
be forced open by passing air flow.
This could cause the hood to come loose
and injure you and others.
Warning!G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature display indicates that the engine is
overheated, do not open the hood. Move
away from vehicle and do not open the hood
until the engine has cooled. If necessary,
call the fire department.
Warning!G
You could be injured when the hood is open
– even when the engine is switched off.
Parts of the engine can become very hot. To
prevent burns, let the engine cool off com-
pletely before touching any components on
the vehicle. Comply with all relevant safety
precautions.
Warning!G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or even restart
after the engine has been turned off. Stay
clear of fan blades.
Warning!G
The engine is equipped with a transistorized
ignition system. Because of the high voltage,
it is dangerous to touch any components
(ignition coils, spark plug sockets,
diagnostic socket) of the ignition system

with the engine running

while starting the engine

if ignition is “on” and the engine is
turned manually

268 Operation
Engine compartment
The hood lock release lever is located to
the left of the steering wheel under the
dashboard.
1Hood lock release lever
Pull release lever1 upward.
The hood is unlocked.
G500
2Safety hook
Lift hood up slightly.
Pull safety hook2 in direction of
arrow.
The hood is unlocked.
Open the hood.
G55AMG
3Safety hook
Lift hood up slightly.
Push safety hook3 in direction of
arrow.
The hood is unlocked.
Open the hood.
!To avoid damage to the windshield wipers or
hood, open the hood only with wipers in parked
position.

269 Operation
Engine compartment
ClosingLower hood and let it drop into lock
from a height of approximately 0.7 ft
(20 cm).
The hood will lock audibly.
Check to make sure the hood is fully
closed.
If you can raise the hood at a point
above the turn signals to the left and
right of the hood, then it is not properly
closed. Open it again and let it drop
with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when

the vehicle is new

the vehicle is driven frequently at
higher engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Warning!G
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure that the hood is securely
engaged before driving off. Do not continue
driving if the hood can no longer engage
after an accident, for example. The hood
could otherwise come loose while the
vehicle is in motion and endanger you and
others.
!Do not push the hood closed manually, as
this could damage it. !Do not use any special lubricant additives,
as these may damage the drive assemblies.
Using special additives not approved by
Mercedes-Benz may cause damage not covered
by the Mercedes-Benz Limited Warranty.
More information on this subject is available at
any Mercedes-Benz Light Truck Center.

270 Operation
Engine compartment
Checking engine oil level with the
control system
When checking the oil level

the vehicle must be parked on level
ground

with the engine at operating tempera-
ture, the vehicle must have been sta-
tionary for at least 5 minutes with the
engine turned off

with the engine not at operating tem-
perature yet, the vehicle must have
been stationary for at least 30 minutes
with the engine turned off
To check the engine oil level via the
multifunction display, do the following:
Switch on the ignition (page 39).
The standard display (
page 140)
should appear in the multifunction
display.
Press buttonk orj on the
multifunction steering wheel until the
following message appears in the
multifunction display:
One of the following messages will
subsequently appear in the multi-
function display:

Engine oil
level
OK

Add
1.0 qt
to reach
maximum
oil level
(Canada: 1.0 liter)

Add
1.5 qts
to reach
maximum
oil level
(Canada: 1.5 liters)

Add
2.0 qts
to reach
maximum
oil level
(Canada: 2.0 liters)
iIf you want to interrupt the checking
procedure, press buttonk orj on the
multifunction steering wheel.