2003 MERCEDES-BENZ CLK320 COUPE coolant

252 OperationAt the gas station
Check regularly and before a long trip
1Coolant level
More information on coolant can be
found in the “Operation” section on
(
page 256).
2Brake fluid (fuse box cover removed)
More information on brake fluid can be
found in the “Technical data” section
on (page 353).
3Windshield washer and headlamp
cleaning system
More information on refilling the reser-
voir can be found in the “Operation”
section on (
page 259).Engine oil level
More information on engine oil can be
found in the “Operation” section on
(
page 254).
Vehicle lighting
Check function and cleanliness.More infor-
mation on replacing light bulbs can be
found in the “Practical hints” section on
(page 316).
Tire inflation pressure
More information on tire inflate pressure
can be found in the “Operation” section on
(page 262).
Opening hood see (
page 253).
Removing fuse box cover see
(
page 337).
Exterior lamp switch see (
page 105)
iLeaving the engine running and the fuel
cap open can cause the
?
lamp to
illuminate.
More information can be found in the
“Practical hints” section (
page 280).

254 OperationEngine compartment
Closing
Let the hood drop from a height of ap-
proximately 1 ft (30 cm).
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 gauge indicates that the engine is
overheated, do not open the hood. Move
away from the vehicle and do not open the
hood until the engine has cooled. If neces-
sary, 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.

256 OperationEngine 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 position 2 in the
starter switch:
Turn on ignition to see engine oil
level!
Switch on the ignition.If you see the message:
Observe waiting time
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.
See “Practical hints” (
page 294) if the
engine oil level indicator lights up in the
display while the engine is running.More information on engine oil can be
found in the “Technical data”
(
page 353).
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.Coolant
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.
!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.
iIf you want to interrupt the checking
procedure, press the
k
or
j
but-
ton on the multifunction steering
wheel.

257 Operation
Engine compartment
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 355).
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 approx-
imately
1⁄2 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.

268 OperationVehicle care
Vehicle careCleaning and care of vehicle
While in operation, even while parked, your
vehicle is subjected to varying external in-
fluences which, if gone unchecked, can at-
tack the paintwork as well as the
underbody and cause lasting damage.
Such damage is caused not only by ex-
treme and varying climatic conditions, but
also by:

Air pollution


Road salt


Tar, gravel and stone chippingTo avoid paint damage, you should imme-
diately remove:


Grease and oil


Fuel


Coolant


Brake fluid


Insects


Tree resins, etc.
Frequent washing reduces and / or elimi-
nates the aggressiveness and potency of
the above adverse influences.
More frequent washings are necessary to
deal with unfavorable conditions:


Near the ocean


In industrial areas (smoke, exhaust
emissions)


During winter operation
You should check your vehicle from time to
time for stone chipping or other damage.
A n y d a m a g e s h o u l d b e r e p a i r e d a s s o o n a s
possible to prevent corrosion.In doing so, do not neglect the underbody
of the vehicle. A prerequisite for a thor-
ough check is a washing of the underbody
followed by a thorough inspection. Dam-
aged areas need to be re-undercoated.
Your vehicle has been treated at the facto-
ry with a wax-base rustproofing in the body
cavities which will last for the lifetime of
the vehicle. Post-production treatment is
neither necessary nor recommended by
Mercedes-Benz because of the possibility
of incompatibility between materials used
in the production process and others ap-
plied later.
We have selected car-care products and
compiled recommendations which are
specially matched to our vehicles and
which always reflect the latest technology.
You can obtain Mercedes-Benz approved
car-care products at your authorized
Mercedes-Benz Center.
Scratches, corrosive deposits, corrosion or
damage due to negligent or incorrect care
cannot always be removed or repaired with
Warning!
G
Many cleaning products can be hazardous.
Some are poisonous, others are flammable.
Always follow the instructions on the partic-
ular container. Always open your vehicle’s
doors or windows when cleaning the inside.
Never use fluids or solvents that are not de-
signed for cleaning your vehicle.

281 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
•
The red coolant warning lamp
lights up when the engine is run-
ning.
There is insufficient coolant in the reservoir.

Add coolant to prevent engine from
overheating (
page 256).
If this warning lamp lights up frequently,
there is a leak in the cooling system.

Have the cooling system checked.
If the coolant level is correct, the electric ra-
diator fan may be broken.

If the coolant temperature is below
257 °F (125 °C), you can continue
driving to the nearest authorized
Mercedes-Benz Center.

Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.
•
The red coolant warning lamp
lights up while driving and you
hear a warning sound.
The coolant temperature has exceeded
257 °F (125 °C).

Stop as soon as possible and allow
the engine and coolant to cool down.
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have
leaked into the engine compartment 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 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.

289 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
F
Key
do not forget key
This display appears (for a maximum of
60 seconds) if the driver’s door is opened
with the engine shut off and no key in the
starter switch.
Message is only a reminder.

Insert key in the starter switch.

Take the SmartKey with KEY-
LESS-GO* with you when leaving the
vehicle.
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 256).

If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Center.
Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
the message and symbol displayed
may cause serious engine damage not
covered by the Mercedes-Benz Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat, causing major en-
gine damage.

290 Practical hintsWhat to do if …?
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display
Possible cause
Suggested solution
Ï
Coolant
Stop, engine off!
The coolant is too hot.

Stop the vehicle and turn off the en-
gine.

Only start the engine again after the
message disappears. You could other-
wise damage the engine.
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have
leaked into the engine compartment 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 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.
!The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
engine damage which is not covered by
the Mercedes-Benz Limited Warranty.