2003 MERCEDES-BENZ C320 COUPE coolant temperature

227 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 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 (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.

229 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 position 2 in the
starter switch:
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:
ENGINE OIL LEVEL - MASURING NOT POS-
SIBLE
Repeat the engine oil level check after
a short while.
See “Practical hints” (
page 262) if an en-
gine oil level indicator appears on the dis-
play when the engine is running.
More information on engine oil can be
found in the “Technical data” section
(
page 317).
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.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.

230 OperationEngine 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” (
page 321)
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 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.

258 Practical hintsWhat to do if …
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 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 oth-
erwise 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.

259 Practical hints
What to do if …
Display
Possible cause
Suggested solution
Ï
COOLANT
STOP, ENGINE OFF!
The poly-V-belt could be broken.

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz
Center.
If it is intact:

Do not continue to drive the vehicle
with this message displayed. Doing
so could result in serious engine
damage that is not covered by the
Mercedes-Benz Limited Warranty.
COOLANT
VISIT WORKSHOP!
The cooling fan for the coolant is malfunc-
tioning.

Observe the coolant temperature
gauge.

Have the fan replaced as soon as
possible.

270 Practical hintsWhat to do if …Display
Possible cause
Suggested solution
#
UNDERVOLTAGE
ENGINE ON!
The battery has insufficient voltage and
can no longer supply the convenience
functions such as seat heater*.
Start the engine (
page 44).
UNDERVOLTAGE
SWITCH CONSUMERS OFF!
The battery is malfunctioning.

Have the battery checked at a ser-
vice station.
G
VISIT WORKSHOP!
DISPLAY DEFECTIVE
The instrument cluster display is malfunc-
tioning.

Continue driving with added caution.

Visit an authorized Mercedes-Benz
Center as soon as possible.
±
VISIT WORKSHOP!
DISPLAY DEFECTIVE
Certain electronic systems are unable to
relay information to the control system.
The following systems may have failed:

Coolant temperature gauge


Tachometer


Cruise control display

Have the electronic systems checked
by an authorized Mercedes-Benz
Center (
page 250).
W
WASHER FLUID
CHECK LEVEL!
The fluid level has dropped to about
1/3 of
total reservoir capacity.

Add washer fluid (
page 232).

317 Technical data
Fuels, coolants, lubricants etc.
Fuels, coolants, lubricants etc.
CapacitiesVehicle components and their respective
lubricants must match. Therefore use only
brands tested and recommended by us. Please refer to the Factory Approved Ser-
vice Products pamphlet, or inquire at your
Mercedes-Benz Center.
Model
Capacity
Fuels, coolants, lubricants etc.
Engine with oil filter
C 230 Kompressor
C320
5.8 US qt (5.5 l)
7.9 US qt (7.5 l)
Recommended engine oils
Automatic transmission
8.5 US qt (8.0 l)
MB Automatic Transmission Oil
1
1MB part no. 001 989 21 03 10Manual transmission
1.3 US qt (1.2 l)
MB Manual Transmission Oil
2
2MB part no. 001 989 26 03 10Rear axle
1.2 US qt (1.1 l)
Hypoid gear oil SAE 85 W 90
Power steering
approx. 1.1 US qt (1.0 l)
MB Power Steering Fluid (Pentosin CHF 11S)
Front wheel hubs
approx. 2.1 oz (60 g) each
High temperature roller bearing grease
Brake system
0.5 US qt (0.5 l)
MB Brake Fluid (DOT 4+)
Cooling system
C 230 Kompressor
C320
approx. 8.5 US qt (8.0 l)
approx. 10.5 US qt (10.0 l)
MB 325.0 Anticorrosion/Antifreeze Agent

318 Technical dataFuels, coolants, lubricants etc.
Model
Capacity
Fuels, coolants, lubricants etc.
Fuel tank
including a reserve of
16.4 US gal (62.0 l)
2.1 US gal (8.0 l)
Premium unleaded gasoline:
Posted Octane 91 (Avg. of 96 RON / 86 MON)
Air conditioning system
R-134a refrigerant and special PAG lubricant oil (never R-12)
Windshield washer and
headlamp cleaning sys-
tem:
Without headlamp clean-
ing system
With headlamp cleaning
system
3.2 US qt (3 l)
6.4 US qt (6 l)
MB Windshield Washer Concentrate
1
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing or MB Windshield Washer Concentrate “S” and commercially available pre-
mixed windshield washer solvent/antifreeze for temperatures below freezing. Follow suggested mixing ratios (
page 324).