2008 MERCEDES-BENZ GL450 coolant level

Contents
Oxidation catalyst
(diesel engine).............................. 371
Emission control .......................... 372
Coolant temperature .................... 372
At the gas station .............................. 374
Refueling ...................................... 374
Check regularly and
before a long trip.......................... 376
Engine compartment ......................... 378
Hood ............................................ 378
Engine oil ..................................... 380
Transmission fluid level ................ 381
Coolant level ................................ 381
Windshield/rear window
washer system and
headlamp cleaning system* ........ 383
Tires and wheels ................................ 384
Important guidelines .................... 384
Tire care and maintenance........... 385
Direction of rotation ..................... 387
Loading the vehicle ...................... 387
Recommended tire
inflation pressure ......................... 393
Checking tire inflation pressure ... 395
Tire labeling.................................. 406
Load identification ....................... 410DOT, Tire Identification
Number (TIN) ................................ 410
Maximum tire load ........................ 412
Maximum tire inflation pressure ... 412
Uniform Tire Quality Grading
Standards (U.S. vehicles) .............. 413
Tire ply material ............................ 415
Tire and loading terminology......... 415
Rotating tires ................................ 418
Winter driving ..................................... 420
Winter tires ................................... 420
Snow chains.................................. 421
Maintenance....................................... 422
Maintenance service indicator
message ....................................... 422
Calling up the maintenance
service indicator display ............... 424
Resetting the maintenance
service indicator ........................... 424
Vehicle care........................................ 425
Cleaning and care of the vehicle ... 425
Practical hints.................................. 435
What to do if … ................................... 436
Lamps in instrument cluster ......... 436
Lamp in center console ................ 447
Vehicle status messages in
the multifunction display .............. 449
Where will I find ...? ............................ 490
First aid kit.................................... 490
Vehicle tool kit.............................. 490
Spare wheel .................................. 494
Unlocking/locking in an emergency .. 496
Unlocking the vehicle ................... 496
Locking the vehicle ....................... 497
Fuel filler flap ................................ 497
Resetting activated head restraints.... 499
Vehicles without Rear seat
entertainment system*................. 499
Vehicles with Rear seat
entertainment system*................. 500
Replacing SmartKey batteries ............ 502
Replacing bulbs .................................. 504
Bulbs............................................. 504
Replacing bulbs for front lamps .... 507
Replacing bulbs for rear lamps ..... 511
Adjusting headlamp aim ............... 514
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65 Getting started
Driving
Deactivating intermittent wipe
Turn rear window wiper switch1 to
position4 (
page 64).
Indicator6 (
page 64) for the rear
window wiper is cleared from the lower
multifunction display, indicating that
the rear window wiper is deactivated.
Wiping with windshield washer fluid
Turn and hold rear window wiper
switch1 in position2 or5
(
page 64) until the rear window is
clean.
The rear window wiper operates with
washer fluid.
For information on filling up the washer
reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 383).
Problems while driving
The engine runs erratically and misfires

An ignition cable may be damaged
(gasoline engine only).

The engine electronics may not be
operating properly.

Unburned gasoline may have entered
the catalytic converter and damaged it
(gasoline engine only).
Give very little gas.
Have the problem repaired by an
authorized Mercedes-Benz Light Truck
Center as soon as possible.The coolant temperature is above
248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle in a safe location as
soon as possible and turn off the en-
gine. Allow engine and coolant to cool
off.
Check the coolant level and add cool-
ant if necessary (
page 381).
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159 Controls in detail
Control system
Menus, submenus and functions
Menu1Menu2Menu3Menu4Menu5
Standard displayAUDIONAV*Off-roadDISTRONIC*
(Canada only)
(page 162)(page 164)(page 166)(page 166)(page 167)
Commands/submenus
Trip- and main odometerSelecting radio stationRoute guidance
instructions, current
direction traveledCompassCalling up settings
Checking tire inflation pressureSelecting satellite radio
station*Vehicle level
Checking coolant temperatureOperating CD playerDifferential locks*
Calling up digital speedometer
or outside temperature
Calling up maintenance service
indicator
iThe headings used in the menus table are
designed to facilitate navigation within the sys-
tem and are not necessarily identical to those
shown in the control system displays.The first function displayed in each menu will
automatically show you which part of the system
you are in.
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376 Operation
At the gas station
Low outside temperatures
(diesel engine)
To prevent malfunctions, diesel fuel with
improved cold flow characteristics is of-
fered in the winter months. Check with
your fuel retailer.Check regularly and before a long trip
Open the hood (page 378).
Example illustration GL 450 (GL 320 CDI,
GL 550 similar)
1Brake fluid
2Coolant level
3Windshield washer system and
headlamp cleaning system*
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 380).
iDiesel engine:
If you have driven the vehicle until the tank is
empty, the fuel system needs to be bled
(
page 527).
!Diesel engine:
The engine is more susceptible to wear and
damage if you use

marine diesel fuel

heating oil

additives
The exhaust aftertreatment device will be
seriously damaged if you use

LOW SULFUR HIGHWAY DIESEL FUEL
(500 ppm SULFUR MAXIMUM)

any other diesel fuel with a sulfur content of
above 15 ppm
The use of such non-approved fuels and/or
special additives is not covered by the
Mercedes-Benz Limited Warranty.
!Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosine. The
fuel system and engine will otherwise be dam-
aged, which is not covered by the
Mercedes-Benz Limited Warranty.

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377 Operation
At the gas station
Brake fluid
Coolant
For normal replenishing, use water (pota-
ble water quality).
For more information, see “Coolant level”
(
page 381) and see “Fuels, coolants, lu-
bricants” (
page 562).Windshield/rear window washer
system and headlamp cleaning
system*
For more information on refilling the wash-
er reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 383).
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 504).
For more information, see “Exterior lamp
switch” (
page 143).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 395).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Light Truck Center
immediately. Do not add brake fluid as this will
not solve the problem. For more information, see
“Brake fluid” (
page 564).
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381 Operation
Engine compartment
Adding engine oil
Example illustration GL 450 (GL 320 CDI,
GL 550 similar)
1Filler cap
Unscrew filler cap1 from filler neck.
Add engine oil as required. Never over-
fill 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” section (
page 562) and
(
page 564).
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.
When checking the coolant level

the vehicle must be parked on level
ground

the coolant temperature must be below
158°F (70°C)
!Only use approved engine oils and oil filters
required for vehicles with Maintenance System.
For a listing of approved engine oils and oil
filters, refer to the Factory Approved Service
Products pamphlet (USA only) in your vehicle
literature portfolio, or contact an authorized
Mercedes-Benz Light Truck Center.
Using engine oils and oil filters of specification
other than those expressly required for the
Maintenance System, or changing of oil and oil
filter at change intervals longer than those called
for by the Maintenance System will result in
engine or emission control system damage not
covered by the Mercedes-Benz Limited
Warranty.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and/or
catalytic converter (gasoline engine) or the oxi-
dation catalyst (diesel engine) not covered by
the Mercedes-Benz Limited Warranty.
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382 Operation
Engine compartment
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.
1Cap
2Coolant expansion tank
3Indicator wall
4Coolant levelUsing a rag, turn cap1 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning cap1 counterclock-
wise and remove it.
Coolant level4 is correct if the level:

for cold coolant: reaches the top of
indicator wall3 visible through the
filling opening

for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap1.
For more information on coolant, see
“Coolants” (
page 567).
Warning!G
In order to avoid potentially 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
indicates 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
under pressure.

Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.
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470 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
Ï Coolant Level
Stop car, switch engine off.The coolant is too hot.
Among other possible causes
(the cooling fan could be
malfunctioning), the poly-V-belt
could be broken.Stop the vehicle in safe location or as
soon as it safe to do so.
Apply the parking brake (page 67).
Turn off the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise, the
engine will overheat due to an inoperative
water pump which may result in damage
to the engine. Contact an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Do not continue to drive the vehicle with
this message displayed. Doing so could
result in serious engine damage that is
not covered by the Mercedes-Benz Limit-
ed Warranty.
(Continued on next page)
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