2008 MERCEDES-BENZ C300 4MATIC engine

415 Practical hints
What to do if …?
When the message Check Engine Oil At
Next Refueling
appears while the engine
is running and at operating temperature,
the engine oil level has dropped to approx-
imately the minimum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.
Visually check for oil leaks. If no obvious oil
leaks are noted, continue to drive to the
nearest service station where the engine
oil should be topped to the required level
with an approved oil specified in the Facto-
ry Approved Service Products pamphlet.
For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
Display Possible cause/consequencePossible solution
ùCheck
Engine Oil
At Next RefuelingThe engine oil level has dropped to approx-
imately the minimum level.Check the engine oil level (page 327) and
add engine oil as required (
page 328).
If you must add engine oil frequently, have
the engine checked for possible leaks.
!The engine oil level warnings should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz Limit-
ed Warranty.

440 Practical hints
Flat tire
Preparing the vehicle
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flashers.
Turn the steering wheel so that the
front wheels are in a straight-ahead
position.
Set the parking brake.
Vehicles with automatic transmission*:
Move the gear selector lever to
positionP (
page 138).
Turn off the engine (page 134).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 135).
Open the driver’s door (this puts
the starter switch in position0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Warning!G
The dimensions of the Minispare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a Minispare wheel
mounted. Adapt your driving style
accordingly.
The Minispare wheel is for temporary use
only. When driving with Minispare wheel
mounted, ensure proper tire inflation
pressure and do not exceed a vehicle speed
of 50 mph (80 km/h).
Contact the nearest Mercedes-Benz Center
as soon as possible to have the Minispare
wheel replaced with a regular road wheel.
Never operate the vehicle with more than
one Minispare wheel mounted.
Do not switch off the ESP
® with a Minispare
wheel mounted.
iOpen the door only when conditions are safe
to do so.

441 Practical hints
Flat tire
Mounting the Minispare wheel
Preparing the vehicle
Prepare the vehicle as described
(
page 440).
Take vehicle tool kit tray and vehicle
jack out of trunk (
page 420).
Take the Minispare wheel from the
wheel well under the trunk floor
(
page 422).Lifting the vehicle
Warning!G
When jacking up the vehicle, only use the
jack which has been specifically approved
by Mercedes-Benz for your vehicle.
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. Make
sure the jack arm is fully seated in the jack
take-up bracket.
The jack is intended only for lifting the
vehicle briefly for wheel changes. It is not
suited for performing maintenance work
under the vehicle. To help avoid personal
injury, use the jack only to lift the vehicle
during a wheel change.
Never get beneath the vehicle while it is sup-
ported by the jack. Keep hands and feet
away from the area under the lifted vehicle.
Always lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.
Always firmly set the parking brake and
block wheels with wheel chocks or other
sizeable objects before raising vehicle with
jack. Do not release the parking brake while
the vehicle is raised.
Make sure that the ground on which the
vehicle is standing and where you place the
jack is solid, level and not slippery. If neces-
sary, use a large underlay. On slippery
surfaces, such as tiled floors, you should
use a non-slip underlay, for example a
rubber mat.
Do not use wooden blocks or similar objects
to support the jack. Otherwise the jack may
not be able to achieve its load-bearing
capacity if it is not at its full height.
Be certain that the jack is always vertical
(plumb line) when in use, especially on hills.
Always try to use the jack on level surface.
Never start the engine when the vehicle is
raised.
Also observe the notes on the jack.

446 Practical hints
Battery
Your vehicle’s battery is located in the
engine compartment.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice 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.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!Do not tow-start the vehicle.
Warning!G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.

447 Practical hints
Battery
1Filter box
2Clamps
Removing filter box: Release
clamps2.
Remove filter box.
Installing filter box: Insert filter box
properly.
Secure it with clamps2.
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and
precautions when handling automotive
batteries (
page 446).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly at an autho-
rized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
Mercedes-Benz Center for further information.
Warning!G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof batteries only to avoid the
risk of acid burns in the event of an
accident.
!Do not connect any consumers directly to
the battery or it will be discharged.

448 Practical hints
Battery
Starter battery
1Battery
2Positive terminal
3Negative terminal
4Ventilation hose
Disconnecting the battery
Apply the parking brake (page 134).
Make sure gear selector lever* is set to
positionP (manual transmission to
Neutral).
Turn off all electrical consumers.
Remove SmartKey from starter switch.Vehicles with KEYLESS-GO* (Canada
only):
Press the start / stop button until
the engine shuts off.
Open the driver’s door.
Open the hood (page 325).
Remove the filter box (page 447).
Read and observe safety instructions
and precautions (
page 446).
Disconnect the battery negative lead
from negative terminal3.
Remove cover from the positive
terminal2.
Disconnect the battery positive lead.iIf the battery is discharged, you must use
the mechanical key to unlock (
page 424) or
lock (
page 425) the vehicle.
Warning!G
With a disconnected battery

you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button (Canada only) will have no effect

vehicles with automatic transmission*:
the gear selector lever will remain
locked in positionP
!Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle’s electronics.

451 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the
battery of another vehicle. Observe the
following:

Jump starting should only be performed
when the engine and catalytic
converter are cold.

Do not start the engine if the battery is
frozen. Let the battery thaw out first.

Only use a12-volt battery to jump start
your vehicle. Jump starting with a high-
er voltage battery could damage the ve-
hicle’s electrical system, which will not
be covered by the Mercedes-Benz
Limited Warranty.

Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.

Always make sure the jumper cables
are not on or near pulleys, fans or other
parts that move when an engine is
started or running.
Warning!G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water, and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Vehicles with automatic transmission*
and/or 4MATIC:
Do not tow-start the vehicle.
!Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine using a bat-
tery quick charge unit.
If engine does not run after several unsuccessful
starting attempts, have it checked at the nearest
authorized Mercedes-Benz Center.
Excessive unburned fuel generated by repeated
failed starting attempts may damage the catalyt-
ic converter and may present a fire risk.
Make sure the jumper cables do not have loose
or missing insulation.
Make sure the cable clamps do not touch any
other metal part while the other end is still at-
tached to a battery.
Warning!G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 446).

452 Practical hints
Jump starting
The battery is located in the engine com-
partment on the right hand side. For jump
starting, use the under hood terminals in
front of the battery.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers,
except hazard warning flashers or work
lights.
Apply the parking brake (page 134).
Make sure gear selector lever* is set to
positionP (manual transmission to
Neutral).
Open the hood (page 326).
Slide red cover2 from positive under
hood terminal3 in direction of arrow. 1Positive terminal of charged battery
2Positive under hood terminal cover
3Positive under hood terminal in front of
discharged battery
4Negative under hood terminal
5Negative terminal of charged battery
Connect positive terminal1 of the
charged battery with positive under
hood terminal3 in front of the dis-
charged battery with the jumper cable.
Clamp cable to charged battery1
first.
Start the engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminal5 of the
charged battery to jumper cables and
attach other end to negative under
hood terminal4 on the vehicle. Clamp
cable to charged battery5 first
Start the engine of the disabled
vehicle.
You can now turn on the electrical con-
sumers. Do not switch on the headlamps
under any circumstances.
Remove the jumper cables first from
the negative terminals4 and5 and
then from the positive terminals3
and1.
You can now switch on the headlamps.
Slide red cover2 from positive under
hood terminal3 back.
Close the hood (page 326).
Have the battery checked at the near-
est authorized Mercedes-Benz Center.
!Never invert the terminal connections.