2005 MERCEDES-BENZ C320 engine

276 OperationAt the gas station
Open the fuel filler flap by pushing at
the point indicated by arrow1.
The fuel filler flap springs open.

Turn fuel cap counterclockwise and
hold on to it until possible pressure is
released.

Take off cap and set it in direction of
arrow2 in the recess on the fuel filler
flap.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.

Only fill your tank until the filler nozzle
unit cuts out – do not top up or
overfill.

Replace fuel cap by turning it
clockwise.
You will hear when fuel cap is
tightened.

Close fuel filler flap.Warning!
G
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gas to
spray back out when removing the fuel
pump nozzle, which could cause personal
injury.
iOnly use premium unleaded gasoline
with a minimum Posted Octane Rating
of 91 (average of 96 RON/86 MON).
Information on gasoline quality can
normally be found on the fuel pump.
More information on gasoline can be
found in the Factory Approved Service
Products pamphlet.
Flexible Fuel Vehicles are identified by
a label reading Premium gasoline or
E85 only! on fuel filler flap.
For more information, see “Flexible
Fuel Vehicles” (
page 392).
iLeaving the engine running and the fuel
cap open can cause theú malfunc-
tion indicator lamp (USA only) or
the± malfunction indicator lamp
(Canada only) to illuminate.
For more information, see “Practical
hints” (
page 304) and (
page 305).


277 Operation
At the gas station
Check regularly and before a long trip
1Coolant
2Brake fluid (fuse box cover removed)
3Windshield washer and headlamp
cleaning system*Coolant
For normal replenishing, use water (pota-
ble water quality). For more information,
see “Coolant level” (
page 283) and see
“Fuels, coolants, lubricants, etc.”
(
page 387).
Brake fluid
Removing fuse box cover (
page 370).Windshield washer and headlamp
cleaning system*
For more information on filling up the
washer reservoir, see “Windshield washer
system and headlamp cleaning system*”
(
page 285).
Engine oil level
For more information on engine oil level,
see “Engine oil” (
page 279).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
“Replacing bulbs” (page 344).
Exterior lamp switch (page 109).
Tire inflation pressure
More information on tire inflation pressure
(
page 287).
iOpening the hood, see (
page 278).
!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.
Notify an authorized Mercedes-Benz
Center immediately. Do not add brake
fluid as this will not solve the problem.
For more information, see “Practical
hints” (
page 303).

278 OperationEngine compartmentHood
Opening
The hood lock release lever is located to
the left of the steering wheel under the
dashboard.
1Hood lock release lever

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
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.

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.