2006 MERCEDES-BENZ ML500 engine overheat

99 Safety and Security
Driving safety systems
Off-road - 4-ETS
With the off-road driving program switched
on (
page 248), the 4-ETS designed for
off-road use is automatically activated.
For more information, see the “Practical
hints” section (
page 382) and
(
page 387).
Warning!
G
When you see ESP
®-warning lampv
flashing in the speedometer, then proceed
as follows:


While driving off, apply as little throttle
as possible.


While driving ease up on the accelera-
tor.


Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4-ETS cannot prevent accidents resul-
ting from excessive speed.
!Because of the ESP’s
® automatic oper-
ation, the engine must be shut off
(
page 34) when the parking brake is
being tested on a brake test dynamom-
eter.
Active braking action through ESP
®
may otherwise seriously damage the
brake system.
Operational tests with the engine
running can only be conducted on a
two-axle dynamometer.
iIf the yellow ESP
® warning lampv
comes on while driving, the 4-ETS is be-
ing switched off temporarily to prevent
overheating of the drive wheel brakes.
In addition, the message
ESP unavail-
able See Operator’s Manual
appears
in the multifunction display.

191 Controls in detail
Automatic transmission
Rocking the vehicle
Rocking the vehicle by shifting betweenD
andR can help free a vehicle stuck in mud
or snow. The engine control system of this
vehicle electronically limits shifting
betweenD andR to very low speeds
(i.e. approx. 2 mph). To shift betweenD
andR, move the gear selector lever past
the resistance point up or down.
Hill start assist system
On uphill grades, the hill start assist
system maintains the pressure in the
brake system for approximately
one second after you have released the
brake pedal. Therefore, you can start off
smoothly without the vehicle moving im-
mediately after releasing the brake pedal.
The hill start assist system is inactive

on driving downhill


in positionN


with the parking brake setWorking on the vehicle
Towing a trailer
If you tow a trailer, note the following
points:

Manually shift to a lower gear range
(page 187) if the transmission hunts
between gears on inclines.
A lower gear range and reduction of
speed reduces the chance to overload
or overheat the engine.
For more information on trailer towing, see
the “Operation” section (
page 314).
Warning!
G
The hill start assist system is not designed
to function as a parking brake and does not
prevent the vehicle from moving when
parked on an incline.
Always set the parking brake in addition to
shifting to park position
P.
iIf the ESP
® has switched off due to a
malfunction, the hill start assist system
is also unavailable.
Warning!
G
When working on the vehicle, set the
parking brake and shift to park positionP.
Otherwise the vehicle could roll away.

301 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream will cool down
the brakes faster.Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.When starting off on a slippery surface, do
not allow a drive wheel to spin for an
extended period with the ESP
® switched
off. Doing so may cause serious damage to
the drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Parking
!When driving down long and steep
grades, relieve the load on the brakes
by shifting into a lower gear to use the
engine’s braking power. This helps
prevent overheating of the brakes and
reduces brake pad wear.
!Simultaneously depressing the
accelerator pedal and applying the
brake reduces engine performance and
causes premature brake and drivetrain
wear.!Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
move gear selector lever to positionP.
When parking on hills, always turn front
wheels towards the curb.
Warning!
G
To reduce the risk of personal injury, or
damage to the vehicle powertrain, as a
result of vehicle/ trailer movement, before
turning off the engine and leaving the vehi-
cle always:

Keep right foot on brake pedal.


Firmly depress parking brake pedal.


Shift the automatic transmission to
positionP.


Slowly release brake pedal and let vehi-
cle and trailer roll into chocks until
stopped.


When parked on an incline, turn front
wheel towards the road curb.


Have a second person place wheel
chocks on downhill side of left and right
trailer wheels.


318 OperationDriving instructions

If the transmission hunts between
gears on inclines, manually shift to a
lower gear (select 4, 3, 2 or 1).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.


On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(page 248).


When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.


If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) 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 hot position.


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 re-
turn to your lane.Uncoupling the trailer

Start the engine (
page 34).

Make sure the automatic transmission
is set toP.

Set the parking brake for the vehicle
(page 52) and for the trailer.

Close all doors and the tailgate.
Detach the trailer immediately after-
ward as follows:

Disconnect all electrical plug connec-
tors.

Uncouple the trailer.
!If the trailer should begin to sway, re-
duce the vehicle’s speed immediately.
In no case attempt to straighten out the
tow vehicle and trailer by increasing
the speed.

320 OperationDriving instructionsControl and operation of radio transmitters
Modular COMAND System, radio and
telephone*Telephones and two-way radios
Radio transmitters, such as a portable
telephone or a citizens band unit should
only be used inside the vehicle if they are
connected to an antenna that is installed
on the outside of the vehicle.
Refer to the radio transmitter operation
instructions regarding use of an external
antenna.
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.
Warning!
G
Do not forget that your primary responsibili-
ty is to drive the vehicle. Only operate the
Modular COMAND System, radio or
telephone
1 if road, weather and traffic con-
ditions 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 (approximate-
ly 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,
possibly resulting in an accident and/or
personal injury.
!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.

322 OperationDriving instructionsCoolant 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 over 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
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 engine 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.

327 Operation
Engine compartment
Closing
Let the hood drop from a height of
approximately 1ft (30cm).
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 headlamps, 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
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge 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
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition 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
Warning!
G
Be careful that you do not close the hood on
anyone.
iDo not use any special lubricant addi-
tives, 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.

332 OperationEngine compartment
Unscrew filler cap1 from filler neck.

Add 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.

Screw filler cap1 back on filler neck.
For more information on engine oil, see
“Technical data” (
page 481).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Light
Truck Center check the automatic trans-
mission.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!Excess oil must be siphoned or drained
off. It could cause damage to the
engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
Warning!
G
In order to avoid any possibly serious burns:

Use 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 gauge indi-
cates that the coolant is overheated.


Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.


Using a rag, slowly open the cap approx-
imately
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.