2003 MERCEDES-BENZ G55AMG Owner's Manual

217 Operation
Engine compartment
Closing
Lower hood and let it drop into lock
from a height of approximately 0.7 ft
(20 cm).
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.
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 re-
strict your warranty entitlement.
More information on this subject is
available at any Mercedes-Benz Light
Truck Center.

218 OperationEngine compartmentChecking 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
With the operating system
You can check the engine oil level on the
multifunction display.

Turn the key in the starter switch to
position2.
The standard display (
page 111) should
appear in the multifunction display.

Press button
k
or
j
on the
steering wheel until the following mes-
sage is seen in the multifunction dis-
play:
ENGINE OIL LEVEL - MEASUREMENT IN
PROCESS! MEASUREMENT CORRECT ONLY
IF VEH. LEVEL
After about three seconds, this mes-
sage is displayed:
ENGINE OIL LEVEL –
MEASURING NOW!
One of the following messages will sub-
sequently appear in the indicator:

ENGINE OIL LEVEL – OK



ENGINE OIL LEVEL – ADD 1.0 QUART
(1.0 LITER)!


ENGINE OIL LEVEL – ADD 1.5 QUART
(1.5 LITER)!


ENGINE OIL LEVEL – ADD 2.0 QUART
(2.0 LITER)!
Other display messages
If there is excessive engine oil with the en-
gine at normal operating temperature, the
following message will appear: ENGINE OIL LEVEL – REDUCE OIL LEVEL! 
Have excess oil siphoned.
If the key is not turned to position2 in the
starter switch:
ENGINE OIL LEVEL – SWITCH ON IGNITION!
Switch on the ignition.
iIf you want to cancel the measuring
process, press the
k
or
j
but-
tons on the multifunction steering
wheel.
!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.
The oil dipstick tube allows for draining
of oil by using a suction device
(page 219).

219 Operation
Engine compartment
If you see the messageOBSERVE WAITING PERIOD 
If engine is at normal operating temper-
ature, wait five minutes before repeat-
ing check procedure.

If the engine is not yet at normal oper-
ating temperature, wait 30 minutes be-
fore repeating check procedure.
If you see the message:
ENGINE OIL LEVEL – NOT WHEN ENGINE ON 
Turn off the engine. If engine is at nor-
mal operating temperature, wait five
minutes before checking oil. If the en-
gine is not yet at normal operating tem-
perature, you must wait 30 minutes
before checking oil.
More information on engine oil can be
found in the “Technical data” section
(
page 316).With the dipstick
1Oil dipstick
2Oil filler cap

Remove oil dipstick1.

Wipe oil dipstick1 clean.

Fully insert oil dipstick1 in tube, and
remove after three seconds to obtain
accurate reading.
Oil dipstick
The oil level is correct when it is be-
tween the lower (min) and upper (max)
mark of the dipstick.

Add engine oil if necessary.iFill quantity between upper and lower
dipstick marking, the level is approxi-
mately 2.1 US qt (2.0 l).

220 OperationEngine compartmentAdding engine oil
Unscrew cap2 from the filler neck.

Add oil. Be careful not to overfill with
oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
coming into contact with the ground or wa-
ter.

Screw cap2 back on the filler neck.
Transmission fluid level
The transmission fluid level does not need
to be checked. The transmission has a per-
manent supply of automatic transmission
fluid.
If you notice transmission fluid loss or gear
shifting malfunctions, have an authorized
Mercedes-Benz Light Truck Center check
the automatic transmission.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking the coolant level

the vehicle must be parked on level
ground


the engine must be cool. The coolant
level should reach the COLD LEVEL
mark in the reservoir.
!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.
The oil dipstick1 tube allows for drain-
ing of oil by using a suction device.
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 display in-
dicates 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
1⁄2turn 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.

221 Operation
Engine compartment
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Cap

Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.

Continue turning the cap to the left and
remove it.

Check coolant level.
The coolant level is correct if the level

for cold coolant: is level with the
mark on the reservoir


for warm coolant: is approx. 0.6 in
(1.5 cm) higher

Add coolant as required.

Replace and tighten cap until you hear
it click a few times. If coolant has to be added, a 50 / 50 mix-
ture of water and
MB Anticorrosion /Antifreeze should be
added.
More information on coolant can be found
in the “Technical data” section
(
page 316).

222 OperationEngine compartmentWindshield/rear window washer sys-tem and headlamp cleaning system
The windshield washer reservoir is located
in the engine compartment on the passen-
ger side. It holds approximately 5.3 US qt
(5.0 l). The headlamp cleaning system is
also supplied from the windshield washer
reservoir.
1Cap

Use the tab to pull cap1 upwards.

Check washer solvent level and add
washer solvent as required.

Press cap1 on the filler neck until is
has completely engaged.
Add MB Windshield Washer Concentrate
“S” to the water during all seasons.


At temperatures above freezing, use
MB Windshield Washer Concentrate
“S” to prevent smearing.


If there is a danger of frost, use
MB Windshield Washer Concentrate
“S” and commercially available pre-
mixed windshield washer solvent/anti-
freeze to prevent water from freezing
on the windshield and the reservoir
from being damaged.
Premix the windshield washer fluid in a
suitable container, adapting the mixing ra-
tio to the outside temperature
(
page 321).
Warning!
G
Washer solvent / antifreeze is highly flam-
mable. Do not spill washer
solvent / antifreeze on hot engine parts, be-
cause it may ignite. You can be seriously
burned.!Only use washer fluid which is suitable
for plastic lenses. Improper washer flu-
id can damage the plastic lenses of the
headlamps.

223 Operation
Battery
Battery
The battery is located in front of the rear
seat bench and below the cup holder. Jump
starting terminals are located in the left
side of the engine compartment
(page 298).
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle less than approxi-
mately 200 miles (300 km) per month,
mostly for short distance trips, or if it is not
used for long periods of time, you will need
to have the battery charge checked more
frequently and corrected if necessary.
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.
More information on battery can be found
in the “Practical hints” section
(
page 295).
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.
iIf the battery is discharged

you will no longer be able to turn
the key in the starter switch


the selector lever will remain
locked in positionP

224 OperationTires and wheels
Tires and wheelsSee your authorized Mercedes-Benz Light
Truck Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and pur-
chase.
Retread tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
Important guidelines

Use only sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire pressure loss and damage to
the tire beads.


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1⁄8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Light Truck Center for fur-
ther information. If incorrectly sized rims
and tires are mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires are no longer guar-
anteed.
Warning!
G
Do not mix different tire construction types
(i.e. radial, bias, bias-belted) on your vehicle
because handling may be adversely affected
and may result in loss of control.Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, use only genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.