2003 MERCEDES-BENZ ML350 engine

199 Operation
Driving instructions
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


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 it
cools down.

201 Operation
At the gas station
Check regularly and before a long trip
Open the hood (
page 202)
1Engine oil level
More information on engine oil can be
found in the “Operation” section
(
page 203).
2Coolant level
For normal replenishing, use water (po-
table water quality). More information
on the coolant level can be found in the
“Operation” section (
page 206).
3Brake fluid
More information on brake fluid can be
found in the “Technical data” section
(
page 284).4Windshield washer and headlamp
cleaning system
More information on filling the reser-
voir can be found in the “Operation”
section (
page 208).
Vehicle lighting
Check function and cleanliness. More in-
formation on replacing light bulbs can be
found in the “Practical hints” section
(
page 247).
Combination switch (
page 102).
Tire inflation pressure
More information on tire inflation pressure
can be found in the “Operation” section
(
page 211).
iLeaving the engine running and the fuel
cap open can cause the
?
lamp to
illuminate.
See also “Practical hints” section
(
page 232).

202 OperationEngine compartment
Engine compartmentHood
Opening
1Hood release

Pull lever1 downwards.
The hood is unlocked. Handle2 pro-
trudes slightly from the radiator trim. If
not, lift the hood slightly.
2Handle for opening the hood

Pull handle2 to its stop out of the radi-
ator grill.

Pull up on the hood and then release it.
The hood will be automatically held
open at shoulder height by gas-filled
struts.
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.
!To avoid damage to the windshield wip-
ers or hood, never open the hood if the
wiper arms are folded forward away
from the windshield.
Warning!
G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running. Make sure the hood is
properly closed before driving. When closing
the hood, use extreme caution not to catch
hands or fingers.
The radiator fan may continue to run for ap-
proximately 30 seconds or even restart af-
ter the engine has been turned off. Stay
clear of fan blades.

203 Operation
Engine compartment
Closing
Let the hood drop from a height of ap-
proximately 1ft (30cm).
The hood will lock audibly.

Check to make sure that 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 high-
er engine speeds.
Engine oil consumption checks should only
be made after the vehicle break-in period.
Checking engine oil level
When checking the oil level the vehicle
must


be parked on level ground


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
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.

204 OperationEngine compartmentEngine oil level display
1Knob
2Display in speedometer
Switch on the ignition and wait until the
display
- - - - - -
appears in the
speedometer display2.

Within one second press knob1 twice.
One of the following messages will subse-
quently appear in the display:


OIL i.OThe oil level is correct. Engine oil does
not to be added.


– 1.0 L
Add 1 liter of engine oil.


– 1.5 L
Add 1.5 liters of engine oil.


– 2.0 L
Add 2 liters of engine oil.


OIL HIThe oil level is too high.
Have excess oil siphoned.The display
- - - - - -
flashes in the
speedometer display if a proper oil level
check cannot be performed.

Repeat the engine oil level check after
a few minutes.
!Excessive 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.
iIf the engine oil level check cannot be
performed again via the display field,
use the dipstick to perform the engine
oil level check (
page 205).
In this case we recommend that you
have the system checked at a
Mercedes-Benz Light Truck Center.

205 Operation
Engine compartment
Oil dipstick
1Oil dipstick
2Oil filler cap
Remove the oil dipstick1.

Wipe the oil dipstick clean.

Fully insert dipstick in tube, and re-
move after three seconds.The engine oil level must be between the
lower (min) and upper (max) mark of the
dipstick.

Add engine oil if necessary.Adding engine oil

Unscrew the oil filler cap2 from the fill-
er neck. 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 the oil filler cap back on the filler
neck.
More information on engine oil can be
found in the “Technical data” section
(
page 286).
iFill quantity between upper and lower
dipstick marking, the level is approxi-
mately 2.1 US qt (2.0 l).
!Excessive 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.

206 OperationEngine compartmentTransmission 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. 1Cap
2COLD LEVEL mark
The coolant level should reach the COLD
LEVEL mark2 in the reservoir.

Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.
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.
iIf the engine is already at its regular op-
erating temperature, the coolant may
be approximately 0.6 in (1.5 cm) above
the COLD LEVEL mark.


207 Operation
Engine compartment

Continue turning the cap to the left and
remove it.

Add coolant as required.

Replace and tighten cap.
More information on coolant can be found
in the “Technical data” section
(
page 287).
Battery
The battery is located in the engine com-
partment.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle mostly for short dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing batteries, always use bat-
teries approved by Mercedes-Benz.If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Light Truck
Center about steps you need to observe.
Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.