MERCEDES-BENZ C320 2005 W203 Owner's Manual

279 Operation
Engine compartment
Closing
Let the hood drop from a height of
approximately 1ft (30cm).
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. Higher 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.
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from vehicle and do not open the hood
until the engine has cooled. If necessary,
call the fire department.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnos-
tic 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.
iDo not use any special lubricant addi-
tives, as these may damage the drive
assemblies. Using special additives not
approved by Mercedes-Benz will
restrict your warranty entitlement.
More information on this subject is
available at any Mercedes-Benz
Center.

280 OperationEngine compartmentChecking engine oil level with the
control system
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 ignition (
page 33).
The standard display (
page 121) 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 indicator:


Engine oil level
OK


Add 1.0 qt engine oil
for max. oil level(Canada:
1.0 l
)


Add 1.5 qts engine oil
for max. oil level(Canada:
1.5 l
)


Add 2.0 qts engine oil
for max. oil level(Canada:
2.0 l
)

If necessary, add engine oil.
For adding engine oil see (
page 281).
More information on engine oil can be
found in the “Technical data” section
(
page 387) and (
page 390).
Other display messages
If the SmartKey is not turned to position2
in the starter switch, the following
message will appear:
Switch ignition on to
check engine oil level
Switch on ignition (
page 33).
iIf you want to interrupt the checking
procedure, press thek orj
button on the multifunction steering
wheel.

281 Operation
Engine compartment
If you see the message:Observe waiting time
If engine is at operating temperature,
wait five minutes before repeating
check procedure.

If engine is not at operating tempera-
ture yet, wait 30 minutes before
repeating 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 Center.
More information on messages in the
display concerning engine oil can be found
in the “Practical hints” section
(
page 320) and (
page 321).Adding engine oil
!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.
!Only use approved engine oils and oil
filters required for vehicles with
Maintenance System (U.S. vehicles) or
FSS (Canada vehicles). For a listing of
approved engine oils and oil filters,
refer to the Factory Approved Service
Products pamphlet in your vehicle
literature portfolio, or contact an
authorized Mercedes-Benz Center.
Using engine oils and oil filters of
specification other than those
expressly required for the Maintenance
System (U.S. vehicles) or FSS (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 (Canada
Vehicles) will result in engine damage
not covered by the Mercedes-Benz
Limited Warranty.

282 OperationEngine compartmentC 230 Kompressor (all models)1Filler cap
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.
C 240 (all models), C 320 (all models),
C55AMG1Filler cap
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.
More information on engine oil can be
found in the “Technical data” section
(
page 387) and (
page 390).
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 Center
check the transmission.
!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.
!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.

283 Operation
Engine compartment
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.
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Coolant expansion tank
2Cap

Using a rag, turn cap2 slowly approx-
imately one half turn to the left to
release 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 black
top part of the reservoir


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

Add coolant as required.

Replace and tighten cap.
For more information on coolant, see
“Coolants” (
page 394).
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
approximately
1/2 turn to relieve excess
pressure. If opened immediately, scald-
ing 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.

284 OperationEngine compartmentBattery
Your vehicle’s battery is located in the
engine compartment on the right hand
side (
page 360).
The battery should always be sufficiently
charged in order to achieve its rated
service life. Refer to Maintenance Booklet
for battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more
frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz 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.
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.

285 Operation
Engine compartment
Windshield washer system and headlamp cleaning system*
The windshield washer reservoir is located
in the engine compartment.
1Washer fluid reservoir cap
Fluid for the windshield washer system and
the headlamp cleaning system* is supplied
from the windshield washer reservoir. It
has a capacity of:

3.2 US qt (3.0 l) in vehicles without
headlamp cleaning system*


6.4 US qt (6.0 l) in vehicles with
headlamp cleaning system*During all seasons, add MB Windshield
Washer Concentrate “S” to water. Premix
the windshield washer fluid in a suitable
container.

Refill the reservoir with MB Windshield
Washer Concentrate and water (or
commercially available premixed
windshield washer solvent/antifreeze,
depending on ambient temperatures).
Always use washer solvent/antifreeze
where temperatures may fall below the
freezing point. Failure to do so could
result in damage to the washer
system/reservoir.For more information, see “Windshield
washer and headlamp cleaning system*”
(
page 396).
!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.

286 OperationTires and wheelsSee an authorized Mercedes-Benz 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. Mercedes-Benz can therefore
not assure the operating safety of the
vehicle when such tires are used.
See an authorized Mercedes-Benz Center
for information on tested and
recommended rims and tires for summer
and winter operation.
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 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 an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension
components can be damaged.


The correct operating clearance of the
wheels and the tires are no longer
guaranteed.
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.

287 Operation
Tires and wheels
Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style


Tire pressure


Distance driven
Direction of rotation
Unidirectional tires offer added advan-
tages, such as better hydroplaning perfor-
mance. To benefit, however, you must
make sure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the
intended direction of tire rotation.
Checking tire inflation pressure
Correct the tire pressure only when tires
are cold.
Regularly check your tire pressure at
intervals of no more than 14 days.
If the tires are warm you should only
correct the tire pressure if it is too low for
current operating conditions.
A table on the fuel filler flap lists the
specified tire inflation pressures for warm
and cold tires as well as for various
operating conditions.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.
Warning!
G
If the tire pressure drops repeatedly:

Check the tires for punctures from
foreign objects.


Check to see whether air is leaking from
the valves or from around the rim.

288 OperationTires and wheels
Tire pressure changes by approx. 1.5 psi
(0.1 bar) per 18°F (10°C) of air tempera-
ture change. Keep this in mind when
checking tire pressure where the tempera-
ture is different from the outside tempera-
ture.
Tire temperature and tire pressure are also
increased while driving, depending on the
driving speed and the tire load.
Check the spare tire periodically for condi-
tion and inflation. Spare tires will age and
b e c o m e w o r n o v e r t i m e e v e n i f n e v e r u s e d ,
and thus should be inspected and replaced
when necessary.
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed in the fuel filler flap.
Warning!
G
Follow recommended inflation pressures.
Do not overinflate tires. Overinflated tires
can result in sudden deflation (blowout)
because they are more likely to become
punctured or damaged by road debris,
potholes, etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indi-
cated by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.