check oil MERCEDES-BENZ R320 2008 W251 Owner's Manual

Contents
Oxidation catalyst
(diesel engine).............................. 349
Emission control .......................... 350
Coolant temperature .................... 350
At the gas station .............................. 352
Refueling ...................................... 352
Check regularly and before a
long trip........................................ 354
Engine compartment ......................... 356
Hood ............................................ 356
Engine oil ..................................... 358
Transmission fluid level ................ 360
Coolant level ................................ 360
Windshield/rear window washer
system and headlamp cleaning
system* ....................................... 362
Tires and wheels ................................ 363
Important guidelines .................... 363
Tire care and maintenance........... 364
Direction of rotation ..................... 365
Loading the vehicle ...................... 366
Recommended tire inflation
pressure ....................................... 371
Checking tire inflation pressure ... 373
Tire labeling.................................. 384
Load identification ....................... 388DOT, Tire Identification Number
(TIN) .............................................. 388
Maximum tire load ........................ 390
Maximum tire inflation pressure ... 390
Uniform Tire Quality Grading
Standards (U.S. vehicles) .............. 391
Tire ply material ............................ 393
Tire and loading terminology......... 393
Rotating tires ................................ 396
Winter driving ..................................... 398
Winter tires ................................... 398
Snow chains.................................. 399
Maintenance....................................... 400
Maintenance service indicator
message ....................................... 400
Calling up the maintenance
service indicator display ............... 402
Resetting the maintenance
service indicator ........................... 402
Vehicle care........................................ 403
Cleaning and care of the vehicle ... 403
Practical hints.................................. 413
What to do if … ................................... 414
Lamps in instrument cluster ......... 414
Lamp in center console ................ 425
Vehicle status messages in the
multifunction display .................... 427
Where will I find ...? ............................ 467
First aid kit.................................... 467
Vehicle tool kit.............................. 467
Spare wheel .................................. 471
Unlocking / locking in an emergency .. 474
Unlocking the vehicle ................... 474
Locking the vehicle ....................... 475
Fuel filler flap ................................ 475
Resetting activated head restraints.... 477
Vehicles without Rear Seat
Entertainment Package................. 477
Vehicles with Rear Seat
Entertainment Package*............... 478
Replacing SmartKey batteries ............ 479
Replacing bulbs .................................. 480
Bulbs............................................. 480
Replacing bulbs for front lamps .... 483
Replacing bulbs for rear lamps ..... 487

23 At a glance
Exterior view
ItemPage
1Tailgate119
Power tailgate*119
Cargo compartment

Loading instructions

Cargo tie-down rings

Hooks

Expanding

Cover blind

Cargo net*
289
290
291
292
299
301
Vehicle tool kit467
Spare wheel471
2Rear window defroster207
3Rear lamps481
4Fuel filler flap352
Refueling352
Fuel353,
540
ItemPage
5Exterior rear view mirrors
Adjusting48
Auto-dimming rear view
mirrors*203
Power folding*204
6Towing eye bolt467
Installing towing eye bolt515
7Tires and wheels363,
529
Checking tire inflation
pressure373
General information363
Flat tire492
Spare wheel471
8Hood
Opening356
Engine oil358
Coolant360
ItemPage
9Windshield wipers59
Wiper blades, replacing489
Wiper blades, cleaning409
aWindshield
Cleaning with wiper fluid61
Cleaning409
bPower tilt/sliding sunroof*248
Panorama roof with power
tilt/sliding panel*252
cDoors
Locking and unlocking110
Opening and closing118
Locking/unlocking in an
emergency474
dFront lamps480
eHeadlamp cleaning system*203

354 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 356).
Example illustration R 350 4MATIC
1Coolant level
2Brake fluid
3Windshield washer system and
headlamp cleaning system*
iDiesel engine:
If you have driven the vehicle until the tank was
empty, the fuel system needs to be bled
(
page 502).
!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.


355 Operation
At the gas station
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 358).
Coolant
For normal replenishing, use water (pota-
ble water quality). For more information,
see “Coolant level” (
page 360) and
“Fuels, coolants, lubricants, etc.”
(
page 536).
Brake fluidWindshield/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 362).
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 480).
For more information, see “Exterior lamp
switch” (
page 143).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 373).
!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. Contact 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 539).

358 Operation
Engine compartment
Closing
Let the hood drop from a height of
approximately 1 ft (30 cm).
The hood will lock audibly.
Check to make sure 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. Increased oil consumption
can occur when

the vehicle is new

the vehicle is driven frequently at
higher 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

the vehicle must have been stationary
for at least 5 minutes with the engine
turned off
Example illustration R 350 4MATIC
1Oil dipstick
2Upper mark
3Lower mark
Open the hood (page 356).
Pull out oil dipstick1.
Warning!G
When closing the hood, use extreme caution
not to catch hand or fingers. Be careful that
you do not close the hood on anyone.
Make sure the hood is securely engaged be-
fore driving. Do not continue driving if the
hood can no longer engage after an accident
for example. The hood could otherwise
come loose while the vehicle is in motion
and injure you and/or others.
!Do not use any special lubricant additives,
as these may damage the drive assemblies.
Using special additives not approved by
Mercedes-Benz may cause damage not covered
by the Mercedes-Benz Limited Warranty.
More information on this subject is available at
any Mercedes-Benz Light Truck Center.

360 Operation
Engine compartment
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 536) and
(
page 538).
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. To check
the coolant level, the vehicle must be
parked on level ground.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine or
emission control system not covered by the
Mercedes-Benz Limited Warranty.
Warning!G
In order to avoid any 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 1/2turn to relieve excess pres-
sure. If opened immediately, scalding


403 Operation
Vehicle care
Vehicle care
Cleaning and care of the vehicle
Regular and proper care will help to main-
tain the value of your vehicle. The best way
to protect your vehicle from harmful envi-
ronmental influences is to wash it and use
protective treatments regularly.While in operation, even while parked, your
vehicle is subjected to varying external in-
fluences which, if gone unchecked, can at-
tack the paintwork as well as the vehicle
underbody and cause lasting damage.
Such damage is caused not only by
extreme and varying climatic conditions,
but also by:

Air pollution

Road salt

Tar

Gravel and stone chipping
To avoid paint damage, you should imme-
diately remove:

Grease and oil

Fuel

Coolant

Brake fluid

Bird droppings

Insects

Tree resins, etc.Frequent washing reduces and/or elimi-
nates the aggressiveness and potency of
the above adverse influences.
More frequent washings are necessary to
deal with unfavorable conditions:

near the ocean

in industrial areas (smoke, exhaust
emissions)

during winter operation
You should check your vehicle from time to
time for stone chipping or other damage.
Any damage should be repaired as soon as
possible to prevent corrosion.
In doing so, do not neglect the underbody
of the vehicle. A prerequisite for a thor-
ough check is a washing of the underbody
followed by a thorough inspection. Dam-
aged areas need to be re-undercoated.
Your vehicle has been treated at the fac-
tory with a wax-base rustproofing in the
body cavities which will last for the lifetime
of the vehicle. Post-production treatment
is neither necessary nor recommended by
Warning!G
Many cleaning products can be hazardous.
Some are poisonous, others are flammable.
Always follow the instructions on the partic-
ular container. Always open your vehicle’s
doors or windows when cleaning the inside.
Never use fluids or solvents that are not de-
signed for cleaning your vehicle.
Always lock away cleaning products and
keep them out of reach of children.

451 Practical hints
What to do if …
When the message Check engine oil
level at next refueling.
appears while
the engine is running and at operating tem-
perature, the engine oil level has dropped
to approximately the minimum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest
service station where the engine oil should
be topped to the required level with an
approved engine oil.
For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Light Truck
Center.
Display symbolDisplay messagePossible cause/consequencePossible solution
NCheck engine oil level
at next refueling.The engine oil level is too low.Check the engine oil level (page 358).
!The engine oil level warning should not be
ignored. Extended driving with the symbol
displayed could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.

540 Technical data
Fuels, coolants, lubricants, etc.
Fuel requirements
Gasoline engine
Only use premium unleaded fuel.

The octane number (posted at the
pump) must be 91 min. It is an
average of both the Research Octane
Number (RON) and the Motor Octane
Number (MON): (RON+MON) /2.
This is also known as the ANTI-KNOCK
INDEX.
Unleaded gasoline containing oxygenates
such as ethanol, IPA, IBA and TBA can be
used provided the ratio of any one of these
oxygenates to gasoline does not
exceed 10%; MTBE must not exceed 15%.
The ratio of methanol to gasoline must not
exceed 3% plus additional cosolvents.
Using mixtures of ethanol and methanol is
not allowed. Gasohol, which contains
10% ethanol and 90% unleaded gasoline,
can be used.These blends must also meet all other fuel
requirements, such as resistance to spark
knock, boiling range, vapor pressure, etc.
Diesel engine
Only use commercially available vehicular
ULTRA-LOW SULFUR HIGHWAY DIESEL
FUEL (15 ppm SULFUR MAXIMUM).
To prevent malfunctions, diesel fuel with
improved cold flow characteristics is
offered in the winter months. Check with
your fuel retailer.
Gasoline additives (gasoline engine)
A major concern among engine
manufacturers is carbon build-up caused
by gasoline. Mercedes-Benz recommends
only the use of quality gasoline containing
additives that prevent the build-up of
carbon deposits.
After an extended period of using fuels
without such additives carbon deposits
can build up, especially on the intake
valves and in the combustion area, leading
to engine performance problems such as:

Warm-up hesitation

Unstable idle

Knocking/pinging

Misfire

Power loss
!Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosine.
The fuel system and engine will otherwise be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.

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