2005 MERCEDES-BENZ C COUPE engine

286 OperationDriving instructionsEmission 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
according to factory specifications. Any
adjustments on the engine should,
therefore, be carried out only by qualified
Mercedes-Benz Center authorized
technicians.
Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly
according to Mercedes-Benz servicing
requirements. For details refer to the
Maintenance Booklet.
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to approximately
248°F (120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious
engine damage which is not covered by
the Mercedes-Benz Limited Warranty.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause un-
consciousness 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.

287 Operation
Driving instructions
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
seriously burned.


Steam from an overheated engine can
cause serious burns and can occur just
by opening the engine hood. Stay away
f r o m t h e e n g i n e i f y o u s e e o r h e a r s t e a m
coming from it. Turn off the engine, get
out of the vehicle and do not stand near
the vehicle until it has cooled down.
Turn off the engine, get out of the vehi-
cle and do not stand near the vehicle
until the engine has cooled down.

288 OperationAt the gas stationRefuelingThe 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.
1To open the fuel filler flap
2Supplemental tire inflation pressure
table
3To insert the fuel filler cap

Turn off the engine.

Remove the SmartKey from the starter
switch.
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 (identified by a label
reading Premium gasoline or E85 only! on
fuel filler flap):
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.

289 Operation
At the gas station

Open the fuel filler flap by pushing at
the point indicated by the arrow1.
The fuel filler flap springs open.

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

Take off the cap and set it in direction
of arrow3 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 the fuel cap by turning it clock-
wise.
You should hear the fuel cap engage.

Close the fuel filler flap.
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.
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 are identified by
a label reading Premium gasoline or
E85 only! on the fuel filler flap.
For more information, see “Flexible
Fuel Vehicles” (
page 431).
iLeaving the engine running and the fuel
cap open can cause the ú malfunc-
tion indicator lamp (USA only) or the
± malfunction indicator lamp
(Canada only) to illuminate.
For more information, see “Practical
hints” section (
page 342).

290 OperationAt the gas stationCheck regularly and before a long trip
1Coolant level
2Brake fluid (fuse box cover removed)
3Windshield washer and headlamp
cleaning system*Brake fluid
Remove fuse box cover before checking
brake fluid (
page 410).
Engine oil level
For more information on engine oil, see
“Engine oil” (page 292).
Opening hood, see (
page 291).Coolant
For normal replenishing, use water (pota-
ble water quality). For more information on
coolant, see “Coolant level” (
page 296)
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 384).
Exterior lamp switch, see (
page 110).
Tire inflation pressure
For information on tire inflation pressure,
see “Checking tire inflation pressure”
(
page 311).
Windshield washer and headlamp
cleaning system*
For more information on filling up the
washer reservoir, see “Windshield washer
system and headlamp cleaning system*”
(page 299).
!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. Noti-
fy 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 341).

291 Operation
Engine compartment
Engine compartment
Hood
Opening the hood
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 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.


292 OperationEngine compartment
Closing the hood
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.
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 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.
iDo not use any special lubricant addi-
tives, as these may damage the drive
assemblies. Using special additives not
approved by Mercedes-Benz may
cause damage not covered by the
Mercedes-Benz Limited Warranty.
More information on this subject is
available at any Mercedes-Benz
Center.


293 Operation
Engine compartment
Checking 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 the ignition (
page 33).
The standard display (
page 123) 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 294).
For more information on engine oil, see
“Technical data” section (
page 426) and
(
page 428).
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 the ignition (
page 33).
iIf you want to interrupt the checking
procedure, press thek orj
button on the multifunction steering
wheel.