2004 MERCEDES-BENZ C320 4MATIC WAGON engine

252 OperationEngine compartment
Engine compartmentHood
Opening
1Hood release

Pull lever1 downwards.
The hood is unlocked and handle2
will extend out of the radiator grille.
2Handle for opening the hood

Pull handle2 to its stop out of the
radiator grille.

Pull up on the hood (do not pull up on
the handle) and then release it.
The hood will be automatically held
open at shoulder height by gas-filled
struts.
Warning!
G
Do not pull the release lever while the
vehicle is in motion. Otherwise the hood
could be forced open by passing air flow.
!To avoid damage to the windshield
wipers or hood, never open the hood if
the wiper arms are folded forward away
from the windshield.
Warning!
G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running. Make sure the hood is
properly closed before driving. When closing
the hood, use extreme caution not to catch
hands or fingers.
The radiator fan may continue to run for
approximately 30 seconds or even restart
after the engine has been turned off. Stay
clear of fan blades.

253 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.
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature display 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.

254 OperationEngine compartmentEngine 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.Checking engine oil level with the
control system
When checking the oil level the vehicle
must


be parked on level ground


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
To check the engine oil level via the
multifunction display, do the following:

Turn the SmartKey in the starter switch
to position2.
The standard display (
page 111) should
appear in the multifunction display.

Press buttonk orj on the
steering wheel until the following
message is seen in the multifunction
display:ENGINE OIL LEVEL
MEASURING NOW
MEASURE. CORRECT
ONLY IF VEH. LEVEL
One of the following messages will
subsequently appear in the indicator:

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
)
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.

255 Operation
Engine compartment

If necessary, add engine oil.
For adding engine oil see (
page 256).
More information on engine oil can be
found in the “Technical data” section
(
page 346) and (
page 348).
Other display messages
If the SmartKey is not turned to position2
in the starter switch, the following
message will appear:
FOR ENGINE OIL LEVEL
SWITCH ON IGNITION!
Switch on the ignition.If you see the message:
OBSERVE WAITING PERIOD
If engine is at normal operating
temperature, wait five minutes before
repeating check procedure.

If engine is not yet at normal operating
temperature, 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 normal operating
temperature, wait five minutes before
checking oil.

If the engine is not yet at normal
operating temperature, you must wait
30 minutes before checking oil.If there is excess engine oil with the engine
at normal operating temperature, the
following message will appear:
ENGINE OIL LEVEL
REDUCE OIL LEVEL
Have excess oil siphoned or drained
off. Contact your authorized
Mercedes-Benz Center.
More information on messages in the
display concerning engine oil can be found
in the “Practical hints” section
(
page 291).
iIf you want to interrupt the checking
procedure, press thek orj
button on the multifunction steering
wheel.
!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.

256 OperationEngine compartmentAdding engine oil
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.
More information on engine oil can be
found in the “Technical data” section
(
page 346) and (
page 348).
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 automatic transmission.
!Only use approved engine oils. For a
listing of approved engine oils, refer to
the Factory Approved Service Products
pamphlet in your vehicle literature
portfolio.
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
printed on the oil filler cap, only use an
engine 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 of other
specification may cause the FSS to
incorrectly determine the next service
interval and will result in engine dam-
age 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.

257 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

Using a rag, turn cap slowly approxi-
mately 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 352).
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 engine temperature is
above 194°F (90°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
1/2turn to relieve ex-
cess pressure. 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.

258 OperationEngine compartmentBattery
Your vehicle’s battery is located in the
engine compartment (
page 324).
The battery should always be sufficiently
charged in order to achieve its rated
service life. Refer to Service Booklet for
battery maintenance intervals.
If you use your vehicle mostly for short-dis-
tance trips, you will need to have the bat-
tery 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.

259 Operation
Engine compartment
Windshield washer system and headlamp cleaning system*
The windshield washer reservoir is located
in the engine compartment.
1Washer fluid reservoir
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 354).
!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.