engine MERCEDES-BENZ G55AMG 2005 W463 Repair Manual

222 OperationDriving instructionsRoad salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.
If the vehicle is parked after being driven
on salt-treated roads, the braking efficien-
cy should be tested as soon as possible af-
ter driving is resumed.
For more information, see “Winter driving”
(
page 275).
Standing water
For more information, see “Driving through
water” (
page 227).
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km / h) vehicle
steering is adversely affected by the LOW
RANGE – ABS (
page 81).
Warning!
G
Make sure not to endanger any other road
users when carrying out these braking ma-
neuvers.
Warning!
G
If the vehicle becomes stuck in snow, make
sure snow is kept clear of the exhaust pipe
and from around the vehicle with the engine
running. Otherwise, deadly carbon monox-
ide (CO) gases may enter vehicle interior re-
sulting in unconsciousness and death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the ve-
hicle not facing the wind.Warning!
G
The outside temperature indicator is not de-
signed to serve as an ice-warning device and
is therefore unsuitable for that purpose. In-
dicated temperatures just above the freez-
ing point do not guarantee that the road
surface is free of ice.
!Do not drive through flooded areas or
water of unknown depth. Before driving
through water, determine its depth.
Never accelerate before driving into
water. The bow wave could force water
into the engine and auxiliary equip-
ment, thus damaging them.
If you must drive through standing wa-
ter, drive slowly to prevent water from
entering the passenger compartment
or the engine compartment. Water in
these areas could cause damage to
electrical components or wiring of the
engine or transmission, or could result
in water being ingested by the engine
through the air intake, causing severe
internal engine damage. Any such dam-
age is not covered by the
Mercedes-Benz Limited Warranty.


225 Operation
Driving instructions
Checklist before off-road driving
Engine oil level

Check the engine oil level
(page 240). The display
ENGINE OIL
LEVEL - OK
must appear in the multi-
function display.
Only then can the vehicle obtain a trou-
ble-free oil supply, even on steep gradi-
ents.
Tires


Check the tread depth and maintain
specified tire inflation pressure
(a placard with the recommended tire
inflation pressures is located on the
driver’s door B-pillar (
page 251)).


Check tires for possible damage and
remove foreign objects.


Replace missing valve caps.Rims


Dented or bent rims can cause tire in-
flation pressure loss and damage the
tire beads. For this reason, check and,
if necessary, change rims before driv-
ing off-road.
Vehicle tool kit


Check if the vehicle jack is functional.


In all cases take the vehicle tool kit, a
strong tow rope, a shovel and a small
plank (to put under the vehicle jack on
sandy soil) with you.


Avoid excessive engine
speeds – drive at moderate engine
speeds (max. 3000 rpm).


Before driving through water, deter-
mine its depth.


Do not stop vehicle while immersed
in water, and do not shut off the en-
gine.


In sandy soil, drive at a steady
speed as allowed by conditions.
This helps overcome the vehicle
rolling resistance and reduces the
likelihood of the vehicle sinking into
the ground.


Do not initiate jumps with the vehi-
cle. It interrupts the forward mo-
mentum of the vehicle.


Always drive on slopes with the en-
gine running and the vehicle in
gear.


Inspect the vehicle for possible
damage after each off-road trip.

226 OperationDriving instructionsDriving in steep terrainSlope angle127°
236°

Comply with the warnings
(page 223) and rules for off-road
driving (
page 224).


Driving on embankments, slopes and
other steep inclines should only be
done straight up or downhill, i.e. in the
line of gravity. Maximum vehicle climb-
ing ability is a 80% grade.


Select gear range2 or1 on the auto-
matic transmission (
page 150).


Drive slowly.


Utilize the engine’s braking power
when descending a slope, observe the
engine speed (do not overrev the en-
gine). Apply the brake as needed.


Check the brakes after a lengthy down-
grade drive.
Traction in steep terrain
Be easy on the accelerator and watch for
continuous wheel traction when driving in
steep terrain.Driving across a hilltop
Decelerate just ahead of a hilltop (do not
select gear rangeN), to prevent the vehi-
cle from speeding up too much after climb-
ing a hill.
Use the momentum of the vehicle to drive
across the hilltop.
After climbing a hill, driving in this manner
prevents the vehicle from:


jumping across the hilltop


loosing its forward momentum


speeding up too much after climbing
the hill
iThe 4-ETS helps greatly when starting
out on a steep incline when the front
wheels have then the tendency to slip
due to the weight shifting away the
front axle.The 4-ETS recognizes the sit-
uation and limits the torque for the
front wheels by braking them. Simulta-
neously the torque for the rear wheels
is provided.

227 Operation
Driving instructions
Driving downhill

Select gear range1 on the automatic
transmission (
page 150).


Drive downhill observing the same
rules as driving uphill (
page 226).Driving through water
119 in (48 cm)


Before driving through water, deter-
mine its depth.
It should not be deeper than approxi-
mately 19 in (48 cm).
Make sure you check the water bed.
The ground surface may not be firm
which may result in deeper waters than
expected when driving the vehicle
through it.


Comply with the warnings
(page 223) and rules for off-road
driving (
page 224).


Switch off the exterior lamps as well as
the climate control.


Select gear range2 or1 on the auto-
matic transmission (
page 150).


Enter the water only at a shallow spot,
driving at walking speed.
!Only apply the service brake if the vehi-
cle is traveling straight downhill, i.e. in
the line of gravity.iThe special LOW RANGE – ABS setting
allows for precise and brief (cyclical)
blocking of the front wheels, permitting
them to dig into loose ground.
Remember that, when stopped, the
front wheels slide across a surface and
thus lose their ability to steer the vehi-
cle.
!Never accelerate before driving into
the water. The bow wave could force
water into the engine and auxiliary
equipment, thus damaging them.

228 OperationDriving instructions

Do not stop vehicle while immersed in
water, and do not shut off the engine.
There is a very high level of driving re-
sistance in water. The surface is slip-
pery and may not be firm, making
pulling away in water difficult and dan-
gerous.


Clean mud off the tire tread after driv-
ing through water.


To dry the brakes, apply pressure to the
brake pedal several times after leaving
the water.Crossing obstacles
!If possible, use the assistance of a sec-
ond person outside the vehicle to scout
the path you intend to take and check
for adequate ground clearance when
you cross obstacles with your vehicle.
The person assisting you outside the
vehicle should always be a safe dis-
tance away from the vehicle and posi-
tioned so that he or she cannot get hurt
in case of any unexpected vehicle
movement.
After off-road driving or crossing obsta-
cles, inspect vehicle for any damage,
especially vehicle underbody and sus-
pension components. Failure to do so
can adversely affect the vehicle’s fu-
ture performance, including increased
chance of an accident.

230 OperationDriving instructionsReturning from off-road drivingOff-road driving increases strain on the ve-
hicle.
We recommend that you inspect the vehi-
cle for possible damage after each off-road
trip. Recognizing any damage and a subse-
quent timely repair reduces the chance of
a possible breakdown or accident later on.
Proceed as follows:


Switch the transfer case in position
HIGH (
page 154).


Disengage differential locks
(page 159).


Remove excessive dirt from tires,
wheels, wheel housings, and under-
body.
For instance, after driving in mud, clean
the radiator, chassis, engine, brakes,
and wheels from extreme dirt using a
strong jet of water.


Inspect frame, oil pan, brake hoses,
etc., as well as vehicle underbody for
possible damage.


Check tires for possible damage and
remove foreign objects. Clean all exte-
rior lamps and conduct a brake test.
Warning!
G
Never drive on pavement with activated dif-
ferential locks. Engaged front axle differen-
tial locks limits ability to move around
curves.
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the roadway.
Inspect the tires and under the vehicle for
possible damage. If the vehicle or tires ap-
pear unsafe, have it towed to the nearest
Mercedes-Benz Light Truck Center or tire
dealer for repairs.
Damage to the vehicle negatively influences
driving comfort and poses the risk of acci-
dent to you and other drivers.

231 Operation
Driving instructions


Clean all exterior lamps and check
them for possible damage.


Check for brush or branches caught in
the underbody.
They could increase the possibility of a
fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the
axles or drive shafts.


After continued operation in mud,
sand, water or other dirty conditions,
clean the brake discs, wheels, brake
pads and check and clean axle joints.


Conduct a brake test.Control and operation of radio trans-
mitters
COMAND, radio and telephone*Telephones and two-way radios
Radio transmitters, such as a portable tele-
phone or citizens band unit should only be
used inside the vehicle if they are connect-
ed to an antenna that is installed on the
outside of the vehicle.
Refer to the radio transmitter operation in-
structions regarding use of an external an-
tenna.Warning!
G
Do not forget that your primary responsibili-
ty is to drive the vehicle safely. Only operate
the COMAND, radio or telephone
1 if road,
traffic and weather conditions permit.
Bear in mind that at a speed of just 30 mph
(approximately 50 km / h), your vehicle is
covering a distance of 44 feet
(approximately 14 m) every second.
1Observe all legal requirements.
Warning!
G
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system, pos-
sibly resulting in an accident and/or
personal injury.

232 OperationDriving instructionsDriving abroad
Abroad, there is an extensive
Mercedes-Benz service network at your
disposal. If you plan to drive into areas
which are not listed in the index of an
Mercedes-Benz Light Truck Center directo-
ry, you should request pertinent informa-
tion from an authorized Mercedes-Benz
Light Truck Center.
Catalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Maintenance Booklet.
!To prevent damage to the catalytic con-
verters, use only premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel
may reach the catalytic converter,
causing it to overheat and potentially
start a fire.

233 Operation
Driving instructions
Emission control
Certain engine systems serve to keep the
toxic components of the exhaust gases
within permissible legal limits.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments 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. More-
over, the specified service jobs must be
carried out regularly according to
Mercedes-Benz servicing requirements.
For details refer to the Maintenance
Booklet.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble materials such as grass, hay or leaves
can come into contact with the hot exhaust
system, as these materials could be ignited
and cause a vehicle fire.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide, and inhaling it can cause uncon-
sciousness and lead to 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 win-
dow fully open at all times.

234 OperationDriving instructionsCoolant temperature
During severe operating conditions, e.g.
stop-and-go city traffic, the coolant tem-
perature may rise to approx. 248°F
(120°C).
The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
iExcessive coolant temperatures trigger
a warning message in the multifunction
display (
page 306).
Warning!
G


Driving when your engine is badly over-
heated can cause some fluids which
may have leaked into the engine com-
partment to catch fire. You could be se-
riously burned.


Steam from an overheated engine can
cause serious burns and can occur just
by opening the hood. Stay away from
the engine if you see or hear steam com-
ing from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.