air filter MERCEDES-BENZ R320 2008 W251 Owner's Manual

211 Controls in detail
Climate control
The climate control is operational when-
ever the engine is running. You can oper-
ate the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 219).
Warning!G
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature).
This may cause burns or frostbite to unpro-
tected skin in the immediate area of the air
vents.
Always keep sufficient distance between un-
protected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 210) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.
Warning!G
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled replacement interval.
A clogged filter will reduce the air volume to
the interior and the windows could fog up,
impairing visibility and endangering you and
others. Have a clogged filter replaced as
soon as possible at an authorized
Mercedes-Benz Light Truck Center.
Warning!G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iIf the vehicle interior is hot, ventilate the in-
terior before driving off, see “Summer opening
feature” (
page 244). The climate control will
then adjust the interior temperature to the set
value much faster.
Keep the air intake grille in front of the wind-
shield free of snow and debris.

225 Controls in detail
3-zone automatic climate control*
The automatic climate control is a 3-zone
intelligent automatic climate control
system. Your vehicle interior is divided
into 3 zones.With the help of a sun sensor, the
automatic climate control determines the
relation of the sun to the vehicle and auto-
matically adjusts the inside temperature
for each individual zone.The automatic climate control is oper-
ational whenever the engine is running. It
cools the vehicle’s interior according to the
angle and intensity of the sun’s rays, the
outside temperature and the selected tem-
perature. You can operate the automatic
climate control in either the automatic or
manual mode.
Nearly all dust particles, pollutants and
odors are filtered out before outside air
enters the passenger compartment
through the air distribution system.
Warning!G
When operating the automatic climate
control, the air that enters the passenger
compartment through the air vents can be
very hot or very cold (depending on the set
temperature). This may cause burns or frost-
bite to unprotected skin in the immediate
area of the air vents.
Always keep sufficient distance between
unprotected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 224) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.Warning!G
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled replacement interval.
A clogged filter will reduce the air volume to
the interior and the windows could fog up,
impairing visibility and endangering you and
others. Have a clogged filter replaced as
soon as possible at an authorized
Mercedes-Benz Light Truck Center.

405 Operation
Vehicle care
Engine cleaning
Prior to cleaning the engine compartment
make sure to protect electrical compo-
nents and connectors from the intrusion of
water and cleaning agents.
Corrosion protection, such as
MB Anticorrosion Wax, should be applied
to the engine compartment after every
engine cleaning. Before applying, all con-
trol linkage bushings and joints should be
lubricated. The poly-V-belt and all pulleys
should be protected from any wax.
Vehicle washing
In the winter, thoroughly remove all traces
of road salt as soon as possible.
When washing the vehicle underbody, do
not forget to clean the inner sides of the
wheels.Hand-wash
Do not use hot water or wash your vehicle
in direct sunlight.
Only use a mild car wash detergent,
such as Mercedes-Benz approved Car
Shampoo.
Thoroughly spray the vehicle with a dif-
fused jet of water.
Direct only a very weak spray towards
the ventilation intake.
Use plenty of water and rinse the
sponge and chamois frequently.
Rinse with clean water and thoroughly
dry with a chamois.
Do not allow cleaning agents to dry on
the finish.Automatic car wash
You can have your car washed in an auto-
matic car wash from the start. Automatic
car washes without brushes are prefera-
ble.
To protect the filter system, switch the
climate control system (
page 208) or
the automatic climate control system*
(
page 222) to air recirculation mode.
If the vehicle is very dirty, prewash it
before running it through the automatic
car wash.
iVehicles with KEYLESS-GO*:
If a door handle is hit by a strong jet of water, and
a SmartKey with KEYLESS-GO* is in close
proximity, i.e. within approximately
3 ft (approximately 1 m), the vehicle could be
inadvertently locked or unlocked.
!Do not use scouring agents on these parts.
Never apply strong force and only use a soft,
non-scratching cloth when cleaning the vehicle.
Do not attempt to wipe the surface with a dry
cloth or sponge.
Otherwise you may scratch or damage the paint.
!Do not clean your vehicle in an automatic
touchless car wash which uses caustic spray.
Otherwise the caustic spray will damage the
paint or ornamental moldings.
!Make sure that the windshield wiper switch
is set to0 (
page 60). Otherwise, the rain
sensor could activate and cause the wipers to
move unintentionally. This may lead to vehicle
damage.
Due to the width of the vehicle, fold in exterior
rear view mirrors prior to running the vehicle
through an automatic car wash to prevent
damage to the mirrors.

444 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
òReplace air filter.The air filter is clogged.Have the air filter checked by an autho-
rized Mercedes-Benz Light Truck Center.
#The battery is no longer charg-
ing.
Possible causes:

alternator malfunctioning

broken poly-V-belt
Do not forget that the brake
system requires electrical
energy and may be operating
with restricted capability.
Considerably greater brake
pedal force is required and the
stopping distance is increased.
Stop the vehicle in a safe location or as
soon as it is safe to do so and 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:
Contact an authorized
Mercedes-Benz Light Truck Center
immediately. Adjust driving to be
consistent with reduced braking
responsiveness.

538 Technical data
Fuels, coolants, lubricants, etc.
Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, 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), or contact an authorized
Mercedes-Benz Light Truck Center.Engine oil additives
Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air condition-
ing system.
ModelCapacityFuels, coolants, lubricants, etc.
Air conditioning systemR-134a refrigerant and special PAG lubricant
oil (never R-12)
Windshield washer
system and headlamp
cleaning system*8.0 US qt (7.6 l)MB Windshield Washer Concentrate1
1Use MB Windshield Washer Concentrate “MB SummerFit” and water for temperatures above freezing point or MB Windshield Washer Concentrate “MB SummerFit”
and commercially available premixed windshield washer solvent/antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 544).
!Using engine oils and oil filters of
specification other than those expressly
required for the Maintenance System, or chang-
ing 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.
Please follow Maintenance System recommen-
dations for scheduled oil changes. Failure to do
so will result in engine or emission control
system damage not covered by the
Mercedes-Benz Limited Warranty.
!Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from blending
oil additives are not covered by the
Mercedes-Benz Limited Warranty.
!Never use R-12 (CFC) or mineral-based
lubricating oil. Otherwise damage to the system
will occur.

551 Index
Engine coolant see Coolant
Engine oil 358, 538
Adding 359, 538
Additives 538
Changing 359, 538
Checking level 358
Consumption 358
Filler neck 359
Recommended engine oils and
filters 538
ESP
®101
Messages in the multifunction
display 435–436
Warning lamp 27, 419
ETD 85
Safety guidelines 74
ETS/4-ETS 103
Extending cargo compartment 292
Exterior rear view mirrors 48, 203
Power folding* 204
Synchronizing 204F
Fastening the seat belts 50
Filler neck, Engine oil 359
First aid kit 467
Flat tire 492
Collapsible tire 471, 498, 532
Jacking up the vehicle 493
Lowering the vehicle 501
Mounting the spare wheel 498
Preparing the vehicle 493
Spare wheel 471, 498, 532
Floormats 335
Fluids
Automatic transmission
fluid 360, 536
Brake fluid 355, 536, 539
Capacities 536
Engine coolant 355, 360, 537, 541
Engine oil 358, 536, 538
Power steering fluid 536
Windshield washer and headlamp
cleaning* system 362, 538Fog lamp, Front see Corner-illuminating
front fog lamps*
Fog lamp, Rear 147
Messages in the multifunction
display 458
Replacing bulbs 480
Fog lamps 146
4MATIC see Permanent four-wheel
drive 281
Front air bags 75
Front defroster 214, 229
Front lamps see Headlamps
Front passenger front
air bag 75, 77, 82, 425
Front passenger front air bag
off indicator lamp 31, 75, 77, 82, 425
Front seat head restraints see
Head restraints
Front towing eye 515