Page 329 of 539

328 OperationEngine compartmentChecking engine oil level with the
control system (ML 500 only)
When checking the oil level
the vehicle must be parked on level
ground
with the engine at operating tempera-
ture, the vehicle must have been
stationary for at least five minutes with
the engine turned off
with the engine not at operating tem-
perature yet, the vehicle must have
been stationary for at least 30 minutes
with the engine turned off
To check the engine oil level via the
multifunction display, do the following:
Switch on the ignition (
page 34).
The standard display (
page 156)
should appear in the multifunction
display.
Press buttonk orj on the
steering wheel until the following
message is seen in the multifunction
display:
One of the following messages will
subsequently appear in the
multifunction display:
Engine oil level ok
Add 1.0 qt. to reach max. oil
level(Canada:
1.0 liter
)
Add 1.5 qts. to reach max. oil
level(Canada:
1.5 liters
)
Add 2.0 qts. to reach max. oil
level(Canada:
2.0 liters
)
If necessary, add engine oil.
For adding engine oil see (
page 495).
For more information on engine oil, see the
“Technical data” section (
page 493) and
(
page 495).iIf you want to interrupt the checking
procedure, press thek orj
button on the multifunction steering
wheel.
Page 330 of 539

329 Operation
Engine compartment
Other display messages
If the SmartKey or KEYLESS-GO*
start/stop button is not in position2, the
following message will appear:Turn on ignition
to see engine oil level
Switch on the ignition (
page 34).
If you see the message:
Observe waiting time
If the engine is at operating
temperature, wait five minutes before
repeating check procedure.
If the engine is not at operating temper-
ature, wait 30 minutes before repeat-
ing check procedure.If you see the message:
Engine oil level
Not when engine on
Turn off the engine.
If the engine is at operating tempera-
ture, wait five minutes before checking
oil.
If the engine is not at operating temper-
ature yet, you must wait 30 minutes
before checking oil.
If there is excess engine oil with the engine
at operating temperature, the following
message will appear:
Engine oil level
Reduce oil level
Have excess oil siphoned or drained
off. Contact an authorized
Mercedes-Benz Light Truck Center.For more information on messages in the
multifunction display concerning engine
oil, see “Practical hints” (
page 381).
!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.
Page 331 of 539

330 OperationEngine compartmentChecking engine oil level with the oil
dipstick (ML 350 only)
When checking the oil level
the vehicle must be parked on level
ground
with the engine at operating tempera-
ture, the vehicle must have been
stationary for at least five minutes with
the engine turned off
with the engine not at operating tem-
perature yet, the vehicle must have
been stationary for at least 30 minutes
with the engine turned offTo check the engine oil level with the oil
dipstick, do the following:
Open the hood (
page 326).
1Oil dipstick
2Upper mark
3Lower mark
Pull out oil dipstick1.
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.The oil level is correct when it is between
the lower3 (min.) and upper2 (max.)
mark of the oil dipstick.
If necessary, add engine oil.
For adding engine oil, see (
page 331).
For more information on engine, see the
“Technical data” section (
page 493) and
(
page 495).iThe filling quantity between the upper
and lower marks on the oil dipstick is
approximately 2.1 US qt. (2.0 l).
Page 332 of 539

331 Operation
Engine compartment
Adding engine oil
Example ML 3501Filler cap
Example ML 5001Filler cap
!Only use approved engine oils and oil
filters required for vehicles with
Maintenance System (U.S. vehicles) or
FSS PLUS (Canada vehicles). For a list-
ing of approved engine oils and oil fil-
ters, refer to the Factory Approved
Service Products pamphlet in your ve-
hicle literature portfolio, or contact an
authorized Mercedes-Benz Light Truck
Center.
In addition, check the oil filler cap for
important information pertaining to the
engine oil needing to meet a specific
Mercedes-Benz specification (e.g.
MB 229.5). If such information is print-
ed on the oil filler cap, only use an en-
gine oil from the list of approved engine
oils in the Factory Approved Service
Products pamphlet that meets the
specification indicated on the oil filler
cap.
Using engine oils and oil filters of spec-
ification other than those expressly re-
quired for the Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles), or changing of oil and oil filter
at change intervals longer than those
called for by the Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles) will result in engine damage
not covered by the Mercedes-Benz
Limited Warranty.
Page 333 of 539

332 OperationEngine compartment
Unscrew filler cap1 from filler neck.
Add engine oil as required. Be careful
not to overfill 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” (
page 481).
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 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 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 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.
Page 334 of 539
333 Operation
Engine compartment
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.
1Coolant expansion tank
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.
The coolant level is correct if the level
for cold coolant: reaches the top of
the indicator wall visible through
the filling opening
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information on coolant, see the
“Technical data” section (
page 497).Windshield/rear window washer
system and headlamp cleaning
system*
The windshield washer reservoir is located
in the engine compartment.
1Cap
Fluid for the windshield washer system and
the headlamp cleaning system* is supplied
from the windshield washer reservoir. It
has a capacity of 8.1 US qt (7.7 l).
Page 335 of 539
334 OperationEngine compartmentDuring all seasons, add MB Windshield
Washer Concentrate “S” to water. Premix
the windshield washer fluid in a suitable
container.
Use the tab to pull cap1 upwards.
Refill the reservoir with MB Windshield
Washer Concentrate “S” and water (or
commercially available premixed wind-
shield washer solvent/antifreeze, de-
pending on ambient temperatures).
Always use washer solvent/antifreeze
where temperatures may fall below
freezing point. Failure to do so could
result in damage to the washer
system/reservoir.For more information, see the “Technical
data” section (
page 500).
!Only use washer fluid which is suitable
for plastic lenses. Improper washer
fluid can damage the plastic lenses of
the headlamps.
Warning!
G
Washer solvent/antifreeze is highly flamma-
ble. Do not spill washer solvent/antifreeze
on hot engine parts, because it may ignite
and burn. You could be seriously burned.
Page 336 of 539

335 Operation
Tires and wheels
Tires and wheels
See an 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
purchase.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. The operating safety of the
vehicle cannot be assured when such tires
are used.
Important guidelines
Only use 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 inflation pressure loss or
damage to the tire beads.
If vehicle is heavily loaded, check tire
inflation 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 an authorized
Mercedes-Benz Light Truck Center for fur-
ther information. If incorrectly sized rims
and tires are mounted:
The wheel brakes or suspension
components can be damaged.
The operating clearance of the wheels
and the tires may no longer be correct.
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, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.