2003 MERCEDES-BENZ C320 4MATIC WAGON Owner's Manual

231 Operation
Driving instructions
Emission control
Certain systems of the engine serve to
keep the toxic components of the exhaust
gases within permissible limits required by
law.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments on the engine should, therefore,
be carried out only by qualified
Mercedes-Benz Center authorized techni-
cians. Engine adjustments should not be
altered in any way. Moreover, the specified
service jobs must be carried out regularly according to Mercedes-Benz servicing re-
quirements. For details refer to the Service
Booklet.
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble materials such as grass, hay or leaves
can come into contact with the hot exhaust
system, as these materials could be ignited
and cause a vehicle fire.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide, and inhaling it can cause uncon-
sciousness and lead to death.
Do not run the engine in confined areas
(such as a garage) which are not properly
ventilated. If you think that exhaust gas
fumes are entering the vehicle while driving,
have the cause determined and corrected
immediately. If you must drive under these
conditions, drive with at least one window
fully open at all times.
Warning!
G


Driving when your engine is badly over-
heated can cause some fluids which
may have leaked into the engine com-
partment to catch fire. You could be se-
riously burned


Steam from an overheated engine can
cause serious burns and can occur just
by opening the engine hood. Stay away
from the engine if you see or hear steam
coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until it
cools down.
S203 MY03_A.book Page 231 Tuesday, January 28, 2003 2:22 PM

232 OperationAt the gas station
At the gas station
The fuel filler flap is located on the
right-hand side of the vehicle towards the
rear. Locking/unlocking the vehicle with
the remote control automatically
locks/unlocks the fuel filler flap.
Remove the key from the starter
switch.

Open the fuel filler flap by pushing at
the point indicated by the arrow.

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

Take off the cap and set it in the recess
on the fuel filler flap.

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

Replace the fuel cap by turning it to the
right.
You will hear when the fuel cap is tight-
ened.

Close the fuel filler flap.
Warning!
G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious inju-
ry. Whenever you are around gasoline, avoid
inhaling fumes and skin contact, extinguish
all smoking materials. Never allow sparks,
flame or smoking materials near gasoline!Warning!
G
Flexible Fuel Vehicles (MY 2003
Mercedes-Benz C 320 models, except those
equipped with manual transmission or
4MATIC*) only:
Ethanol fuel (E85) and its vapors are highly
flammable, poisonous and burn easily. Etha-
nol fuel can cause serious injuries if ignited
or if you come into contact with it or inhale
fumes of it. Avoid inhalation of Ethanol
fumes and skin contact with Ethanol. Extin-
guish all open flames before refueling. Never
smoke or create sparks close to Ethanol.
Warning!
G
Overfilling of the fuel tank may create pres-
sure in the system which could cause a gas
discharge. This could cause the gas to spray
back out when removing the fuel pump noz-
zle, which could cause personal injury.
S203 MY03_A.book Page 232 Tuesday, January 28, 2003 2:22 PM

233 Operation
At the gas station
Check regularly and before a long trip
1Coolant level
More information on the coolant level
can be found in the “Operation” section
(
page 238).
2Brake fluid (fuse box cover removed)
More information on brake fluid can be
found in the “Technical data” section
(page 330).
3Windshield washer and headlamp
cleaning system
For more information on refilling the
reservoir, see the “Operation” section
(page 240).Engine oil level
More information on engine oil can be
found in the “Operation” section
(
page 235).
Opening hood (
page 234).
Coolant
For normal replenishing, use water (pota-
ble water quality). More information on
coolant can be found in the “Operation”
section (
page 238).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
the “Practical hints” section (
page 292).
Exterior lamp switch (
page 98).
Tire inflation pressure
More information on tire inflation pressure
can be found in the “Operation” section
(
page 242).
iUse only 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: MY 2003
Mercedes-Benz C320 models, except
those equipped with manual transmis-
sion or 4MATIC*.
More information on Flexible Fuel Vehi-
cles can be found in the “Technical Da-
ta” section (
page 332).
iLeaving the engine running and the fuel
cap open can cause the
?
lamp to
illuminate.
See also “Practical hints” section
(
page 258).
S203 MY03_A.book Page 233 Tuesday, January 28, 2003 2:22 PM

234 OperationEngine compartment
Engine compartmentHood
Opening
1Hood release
Pull lever1 downwards.
The hood is unlocked.2Handle for opening the hood

Pull handle2 to its stop out of the radi-
ator grill.

Pull up on the hood 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 vehi-
cle is in motion. Otherwise the hood could
be forced open by passing air flow.
!To avoid damage to the windshield wip-
ers 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 ap-
proximately 30 seconds or even restart af-
ter the engine has been turned off. Stay
clear of fan blades.
S203 MY03_A.book Page 234 Tuesday, January 28, 2003 2:22 PM

235 Operation
Engine compartment
Closing
Let the hood drop from a height of ap-
proximately 1ft (30cm).
The hood will lock audibly.

Check to make sure that 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 high-
er 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


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
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 (ig-
nition coils, spark plug sockets, diagnostic
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
S203 MY03_A.book Page 235 Tuesday, January 28, 2003 2:22 PM

236 OperationEngine compartmentYou can check the engine oil level on the
multifunction display.
Turn the key in the starter switch to
position2.
The standard display (
page 112) should
appear in the multifunction display.

Press button
k
or
j
on the
steering wheel until the following mes-
sage is seen in the multifunction dis-
play:
ENGINE OIL LEVEL – MEASUREMENT IN
PROCESS! CORRECT MEASUREMENT ONLY
IF VEH. LEVEL
After about three seconds this mes-
sage is displayed:
ENGINE OIL LEVEL –
MEASURING NOW
One of the following messages will sub-
sequently appear in the indicator:

ENGINE OIL LEVEL – OK



ENGINE OIL LEVEL – ADD 1 QUART
(1.0 LITER)!


ENGINE OIL LEVEL – ADD
1.5 QUARTS (1.5 LITERS)!


ENGINE OIL LEVEL – ADD 2 QUARTS
(2.0 LITERS)!
Adding engine oil
1Filler neck
Unscrew the cap from filler neck1. 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.!Excessive 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.
S203 MY03_A.book Page 236 Tuesday, January 28, 2003 2:22 PM

237 Operation
Engine compartment

Screw the cap back on the filler neck.
Other display messages
If there is excessive engine oil with the en-
gine at normal operating temperature, the
following message will appear:
ENGINE OIL LEVEL – REDUCE OIL LEVEL 
Have excess oil siphoned.
If the key is not turned to position2 in the
starter switch, the following message will
appear:
FOR ENGINE OIL LEVEL IGNITION ON
PLEASE!
Switch on the ignition.If you see the message:
OBSERVE WAITING PERIOD
Wait five minutes before repeating
check procedure.
If you see the message:
ENGINE OIL LEVEL – NOT WHEN ENGINE ON! 
Turn off the engine. If engine is at nor-
mal operating temperature, wait five
minutes before checking oil. If the en-
gine is not yet at normal operating tem-
perature, you must wait 30 minutes
before checking oil.
If a proper oil level check cannot be per-
formed, the following message will appear:
MEASURING NOT POSSIBLE
.

Repeat the engine oil level check after
a short while.
More information on engine oil can be
found in the “Technical data” section
(
page 330).
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.
S203 MY03_A.book Page 237 Tuesday, January 28, 2003 2:22 PM

238 OperationEngine compartmentCoolant 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 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 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.
More information on coolant can be found
in the “Technical data” section
(
page 334).
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 display in-
dicates 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 approx-
imately ½ 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.
S203 MY03_A.book Page 238 Tuesday, January 28, 2003 2:22 PM