engine overheat MERCEDES-BENZ ML350 2004 W163 Owner's Manual

79 Safety and Security
Driving and safety systems
4-ETS
The 4-Electronic Traction System (4-ETS)
improves vehicle’s ability to utilize avail-
able traction, especially under slippery
road conditions. The brakes are applied to
the spinning wheel and power is trans-
ferred to the wheel(s) with traction.
The traction control engages at vehicle
speeds up to approximately 24 mph
(40 km / h), and switches off at approxi-
mately 50 mph (80 km / h).
The {indicator lamp in the instrument
cluster (
page 25) comes on when you
turn the key to position2. It goes out when
the engine is running.
The 4-ETS / ESP warning lampv, loca-
ted in the speedometer dial, starts to flash
at any vehicle speed, as soon as the tires
lose traction and the wheels begin to spin.
Warning!
G
When you see the 4-ETS / 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 opera-
tion, the engine must be shut off
(SmartKey in starter switch position0
or1) when the parking brake is being
tested on a brake test dynamometer.
Active braking action through ESP may
otherwise seriously damage the front
or rear axle brake system.
Operational tests with the engine
running can only be conducted on a
two-axle dynamometer.iIf the yellow 4-ETS malfunction indica-
tor lamp{ comes on while the
4-ETS / ESP warning lampv flash-
es, the electronic traction system is be-
ing switched off temporarily to prevent
overheating of the drive wheel brakes.

117 Controls in detail
Instrument cluster
Coolant temperature gauge
Under normal driving conditions, the cool-
ant temperature may rise to 248°F
(120°C). The coolant temperature may
climb to the red marking:

at high outside temperatures


during stop-and-go city traffic


when driving on hilly terrain
The engine should not be operated with
the coolant temperature in the red zone.
Doing so may cause serious engine dam-
age which is not covered by the
Mercedes-Benz Limited Warranty.
Display in the speedometer
Changing display
Press the left knob1 in the instru-
ment cluster (
page 116).
The display changes between main
odometer and trip odometer.

Press the left knob1 twice.
The next scheduled service is displayed
(page 232).
Warning!
G
Driving when your engine is badly overheat-
ed 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 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.

124 Controls in detailAutomatic transmissionTowing a trailer
If you tow a trailer, note the following
points:

Manually shift to a lower gear range
(4,3, 2, 1), if the transmission hunts
between gears on inclines
(page 121).
A lower gear range and reduction of
speed reduces the change to overload
or overheat the engine.


At very steep inclines switch transfer
case to LOW RANGE mode
(page 125).
For more information on trailer towing, see
the “Operation” section (
page 206).Emergency operation (Limp Home
Mode)
If vehicle acceleration worsens or the
transmission no longer shifts, the trans-
mission is most likely operating in limp
home (emergency operation) mode. In this
mode only second gear and reverse gear
can be activated.
Stop the vehicle.

Move gear selector lever to positionP.

Turn off the engine.

Wait at least ten seconds before
restarting.

Restart the engine.

Move selector lever to positionD
(for second gear) orR.

Have the transmission checked at an
authorized Mercedes-Benz Light Truck
Center as soon as possible.

195 Operation
Driving instructions
Install only brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so 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 ex-
tended 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.
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
!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.

210 OperationDriving instructions

The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
I t i s m o r e p r o n e t o r e a c t i n g t o s i d e w i n d
gusts, and requires more sensitive
steering input.


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 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 gear selector lever in position1,
switch transfer case to LOW RANGE
mode (
page 125).


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.
!If the trailer should begin to sway, re-
duce the vehicle’s speed and use the
brake controller by hand to straighten
out the vehicle and trailer.
In no case should you attempt to
straighten out the tow vehicle and trail-
er by increasing the speed or overstee-
ring and stepping on the brakes.

212 OperationDriving instructionsTelephones and two-way radios
Radio transmitters, such as a portable tele-
phone or a citizens band unit should only
be used inside the vehicle if they are con-
nected 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.
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 Service Booklet.
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
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.
!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 start a fire.
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.

213 Operation
Driving instructions
carried out regularly according to
Mercedes-Benz servicing requirements.
For details refer to the Service Booklet.
Coolant temperature
During severe operating conditions and
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 in the red zone.
Doing so may cause serious engine dam-
age 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, 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.
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.

218 OperationEngine compartment
Closing
Let the hood drop from a height of ap-
proximately 1 ft (30 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 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.!Do not push the hood closed manually,
as this could damage it.
iDo not use any special lubricant addi-
tives, as these may damage the drive
assemblies. Using special additives not
approved by Mercedes-Benz will
restrict your warranty entitlement.
More information on this subject is
available at any Mercedes-Benz Light
Truck Center.


222 OperationEngine compartment
Screw filler cap2 back on filler neck.
More information on engine oil can be
found in the “Technical data” section
(
page 300) and (
page 301).
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
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 engine temperature is above
194°F (90°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 ½ 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.


249 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
/
The yellow coolant warning lamp
comes on when the engine is
running.
The coolant is to hot.
The coolant level is too low.

Stop as soon as possible and allow
the engine and coolant to cool down.

Check the coolant level and add
coolant if necessary (
page 222).
If the warning lamp comes on frequently,
there is a leak in the cooling system.

Have the cooling system checked by
an authorized Mercedes-Benz Light
Truck Center.
The coolant temperature gauge is above
248 °F (120 °C).
The coolant level is too low.

Stop as soon as possible and allow
the engine and coolant to cool down.

Add coolant to prevent engine from
overheating (
page 222).
If the coolant level is correct, the electrical
radiator fan may be broken.

If the coolant temperature is below
the red zone, drive on to the nearest
authorized Mercedes-Benz Light
Truck Center.
Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.