2004 MERCEDES-BENZ ML350 hood open

220 OperationEngine compartmentThe display
------
flashes in the
speedometer display, if a proper oil level
check cannot be performed.

If engine is at normal operating
temperature, wait five minutes before
repeating check procedure.

If engine is not yet at normal operating
temperature, wait 30 minutes before
repeating check procedure.
See the “Practical hints” section
(
page 253) if the low engine oil level
warning lamp in the instrument cluster
flashes.Checking engine oil level with the oil
dipstick
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
To check the engine oil level with the oil
dipstick, do the following:

Open the hood (
page 217).

Pull out oil dipstick1 (
page 221).

Wipe oil dipstick1 clean.

Fully insert oil dipstick1 into the
dipstick guide tube.

Pull out oil dipstick1 again after
approximately three seconds to obtain
accurate reading.
Oil dipstickThe oil level is correct when it is between
the lower (min) and upper (max) mark of
the oil dipstick.
iPerform the engine oil level check with
the dipstick if it cannot be completed
via the speedometer display
(page 220).
In this case we recommend that you
have the system checked at a
Mercedes-Benz Light Truck Center.
iThe engine oil level can be checked by
either the oil dipstick or via the
speedometer display in the instrument
cluster (
page 219). The amount of
engine oil needed is shown more
precisely in the speedometer display.

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.


250 Practical hintsWhat to do if …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.Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You can be seriously burned.
!Do not ignore the coolant warning
lamps. Extended driving with the sym-
bol displayed may cause serious engine
damage not covered by the
Mercedes-Benz Limited Warranty.
Do not drive without sufficient amount
of coolant. The engine will overheat,
causing major engine damage.

268 Practical hintsReplacing bulbsReplacing bulbs for front lamps
Replacing low beam bulbs
1Low beam halogen or Bi-Xenon* head-
lamp cover with locking tab2Electrical connector
Bi-Xenon* headlampHalogen headlamp

Switch off the lights.

Open the hood (
page 217).

Push down tab at top end of cover1
and remove.

Pull electrical connector2 off.

Unclip the retainer springs and take out
the bulb.

Insert the new bulb so that the base lo-
cates in the recess on the holder.

Clip the retainer springs.

Plug the connector2 onto the bulb.

Align headlamp cover and click into
place.
Warning!
G
Do not remove the cover
1
for the
Bi-Xenon headlamp. Because of high voltage
in xenon lamps, it is dangerous to replace
the bulb or repair the lamp and its compo-
nents. We recommend that you have such
work done by a qualified technician.

269 Practical hints
Replacing bulbs
High beam bulbs
1High beam headlamp cover with lock-
ing tab
Switch off the lights.

Open the hood (
page 217).

Twist cover1 counterclockwise and
remove.2Electrical connector

Pull electrical connector2 off.

Unclip the retainer springs and take out
the bulb.

Insert the new bulb so that the base lo-
cates in the recess on the holder.

Clip the retainer springs.

Plug the connector2 onto the bulb.

Align headlamp cover and click into
place.Turn signal, parking, standing and side
marker lamp bulbs
1Bulb socket

Switch off the lights.

Open the hood (
page 217).

Twist bulb socket1 counterclockwise
and pull out.

Push bulb into socket, turn counter-
clockwise and remove.

Insert new bulb in socket, push in and
twist clockwise.

Reinstall the bulb socket.


272 Practical hintsReplacing bulbs
Insert reflector from the left so that it
engages on the right.

Position tabs of cover in slots and rein-
stall cover until properly seated.
Adjusting headlamp aim
VVertical centerline
HHeadlamp mounting high, measured
from the centerCorrect headlamp adjustment is extremely
important. To check and readjust a head-
lamp, follow the steps described:

Park the vehicle on a level surface
25 feet (7.6 m) from a vertical test
screen or wall.

Switch the headlamps on
(page 110).
If the beam does not show a beam pattern
as indicated in the figure left, then follow
the steps below:

Open hood (
page 217).
2Headlamp vertical adjustment screw
3Headlamp vertical adjustment screw

Always turn adjustment screws2
and3 simultaneously for vertical ad-
justment until the headlamp is adjust-
ed as shown1. Turn clockwise for
upward movement and counterclock-
wise for downward movement.
Graduations:
screw2: 0.50° pitch
screw3: 0.67° pitch
The left and right headlamps must be ad-
justed individually.
iHigh beam adjustments simultaneous-
ly aim the low beam.
Vehicle should have a normal trunk
load.
iIf it is not possible to obtain a proper
headlamp adjustment, have the system
checked at your authorized
Mercedes-Benz Light Truck Center.


273 Practical hints
Replacing wiper blades
Replacing wiper blades
Removing
Fold the wiper arm forward.

Turn wiper blade at a right angle to wip-
er arm.
1Wiper blade
2Safety tab

Press safety tab down2.

Push wiper blade downward1 and re-
move.
Installing
Slide the wiper blade into end of wiper
arm until it locks in place.

Fold the wiper arm back to rest on the
windshield. Make sure you hold onto
the wiper when folding the wiper arm
back.
Warning!
G
For safety reasons, remove key from steer-
ing lock before replacing a wiper blade. Oth-
erwise the motor could suddenly turn on and
cause injury.
!Never open the hood when the wiper
arms are folded forward.
Hold on to the wiper when folding the
wiper arm back. If released, the force
of the impact from the tensioning
spring could crack the windshield.
Do not allow the wiper arms to contact
the windshield glass without a wiper
blade inserted.
Make certain that the wiper blades are
properly installed. Improperly installed
wiper blades may cause windshield
damage.
For your convenience, we recommend
that you have this work carried out by
an authorized Mercedes-Benz Center.

279 Practical hints
Battery
Disconnecting the battery
Depress parking brake firmly or move
gear selector lever to positionP.

Turn off all electrical consumers.

Remove key from the steering lock.

Open the hood (
page 217).

Disconnect the battery negative lead.

Remove the cover from the positive ter-
minal.

Disconnect the battery positive lead.
Removing the batteries
Remove the screw securing the bat-
tery.

Remove the battery support and brack-
et. Take out the battery.
Charging and reinstalling batteries
Charge battery in accordance with the
instructions of the battery charger
manufacturer.

Reinstall the charged battery. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.

Connect the positive lead and fasten its
cover.

Connect the negative lead.
Warning!
G
With a disconnected battery

you will no longer be able to turn the key
in the steering lock


the gear selector lever will remain
locked in positionP
Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
!Never invert the terminal connections!!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.