2008 MERCEDES-BENZ C300 4MATIC coolant temperature

329 Operation
Engine compartment
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.
1Cap
2Coolant expansion tank
3Fluid level bridgeUsing a rag, turn cap1 slowly approx-
imately a half-turn counterclockwise to
release any excess pressure.
Continue turning the cap1 counter-
clockwise and remove it.
The coolant level is correct if the level

for cold coolant: reaches the white
marking (plastic bridge)3 inside the
coolant expansion tank2

for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap1.
For more information on coolant, see the
“Technical data” section (
page 484).
Warning!G
In order to avoid potentially 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 coolant temperature is
above 158°F (70°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 a half-turn to relieve excess
pressure. If opened immediately, scald-
ing hot fluid and steam will be blown out
under 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.

402 Practical hints
What to do if …?
During severe operating conditions,
e.g. stop-and-go traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display Possible cause/consequencePossible solution
•Coolant Low
Stop Vehicle!
Turn Engine OffThe coolant is too hot. Stop the vehicle in a safe location or as soon
as it is safe to do so and immediately turn off
the engine.
Only start the engine again after the message
disappears. You could otherwise damage the
engine.
Observe the coolant temperature gauge in
the instrument cluster (
page 26).
Warning!G

Driving when your engine is overheated
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 which can occur
just by opening the engine hood. Stay
away from the engine if you see or hear
steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of
the vehicle and do not stand near the vehicle
until the engine has cooled down.!The engine should not be operated with the
coolant temperature above 248°F (120°C). Do-
ing so may cause serious engine damage which
is not covered by the Mercedes-Benz Limited
Warranty.

403 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
•Coolant Low
Stop Vehicle!
Turn Engine OffThe poly-V-belt could be broken.Stop the vehicle in a safe location or as soon
a s it is sa fe t o do so and im media tely turn off
the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative water
pump which may result in damage to the en-
gine.
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.
Observe the coolant temperature gauge in
the instrument cluster (
page 26).
(Continued on next page)

404 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
•Coolant Low
Stop Vehicle!
Turn Engine OffRestart the engine.
If this message disappears from the multi-
function display:
Drive immediately to the nearest autho-
rized Mercedes-Benz Center.
If this message does not disappear from the
multifunction display:
Call Roadside Assistance.
•The cooling fan for the coolant is malfunc-
tioning.Observe the coolant temperature gauge in
the instrument cluster (
page 26).
Have the fan replaced as soon as possible.

478 Technical data
Fuels, coolants, lubricants, etc.
ModelCapacityFuels, coolants, lubricants, etc.
Power steeringAll models0.85 US qt. (0.8 l)MB Power Steering Fluid
(Chevron Texaco PSF 9109)1
1For detailed information, please refer to the Factory Approved Service Products pamphlet (USA only) or contact an authorized Mercedes-Benz Center.
Front wheel hubsAll modelsapprox. 3.6 oz. (95 g) eachHigh-temperature roller bearing grease
Brake systemAll modelsapprox. 0.53 US qt. (0.5 l)MB Brake Fluid (DOT 4+)
Cooling systemAll models5.07 US qt. (4.8 l)MB 325.0 Anticorrosion/Antifreeze
Fuel tank
including a reserve ofAll models17.43 US gal (66.0 l)
2.11 US gal (8.0 l)Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)
C 300 and C 300 Sport (with automatic
transmission*), USA only:
Flexible Fuel Vehicle (identified by a label
reading Premium gasoline or E85 only!
on fuel filler flap).
Alternative fuel: Ethanol fuel (E85)
Air conditioning systemAll modelsR-134a refrigerant and special PAG
lubricant oil (never R-12)

479 Technical data
Fuels, coolants, lubricants, etc.
ModelCapacityFuels, coolants, lubricants, etc.
Windshield washerC 230 (all models)1
1Canada only.
4.23 US qt (4.0 l)MB Windshield Washer Concentrate2
2Use MB Windshield Washer Concentrate “MB SummerFit” and water for temperatures above freezing point or MB Windshield Washer Concentrate “MB SummerFit”
and commercially available premixed windshield washer solvent/antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 486).
C 350 4MATIC14.23 US qt (4.0 l)
C 350 4MATIC Sport14.23 US qt (4.0 l)
C 300 (all models)6.34 US qt (6.0 l)
C 35016.34 US qt (6.0 l)
C 350 Sport6.34 US qt (6.0 l)

483 Technical data
Fuels, coolants, lubricants, etc.
Switching fuels
For best performance and driveability it is
recommended to use either one or the oth-
er fuel. A refueling pattern that alternates
between the two different fuels should be
avoided if possible.
When switching fuels, make sure:

Fuel level is below half full.

Fuel level is above reserve (reserve
warning lamp is not lit).

Amount of added fuel is more than
5 gallons (20 liters).

Ignition is off during refill.

Immediately after refueling engine is
started and operated for at least five
minutes.
These precautions and recommendations
are supposed to prevent any difficulties
when starting and operating the engine
which otherwise may be experienced
before the engine has fully adapted to the
different fuel.If in spite of these recommendations the
engine does not perform properly, adding
more gasoline (at least 3 gallons
[12 liters]) to the fuel may improve the
engine behavior.
Cruising range
E85 fuel contains less energy per gallon
than gasoline. To ensure that engine per-
formance with Ethanol fuel is similar to
that when using gasoline, the engine must
burn more Ethanol fuel. As a result, it is to
be expected that the fuel consumption will
increase when using E85 compared to
gasoline operation.
Maintenance
Please inform your authorized
Mercedes-Benz Center if you use or have
used E85 fuel when your vehicle is deliv-
ered for maintenance or repairs.Cold weather performance
It is possible that starting times will signif-
icantly increase at temperatures below
32°F (0°C). At low temperatures the use
of a block heater is recommended (see an
authorized Mercedes-Benz Center for fur-
ther information). Rough idling may also be
experienced at such temperatures before
the engine is fully warmed up.
Hot weather performance
At ambient temperatures above 95°F
(35°C) start times may increase and be
accompanied by a rough idle following the
start.iUse of E85 may reduce your driving range.
!E85 fuel is unsuitable for use when ambient
temperatures fall below 14°F (-10°C).

484 Technical data
Fuels, coolants, lubricants, etc.
Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which pro-
vides:

Corrosion protection

Freeze protection

Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -22°F (-30°C) and corro-
sion protection.
If the antifreeze mixture is effective to
-22°F (-30°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. Refer to Maintenance Booklet for re-
placement interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable if
MB 325.0 Anticorrosion/Antifreeze solu-
tion or other Mercedes-Benz approved
products of equal specification are used to
renew the coolant concentration or bring it
back up to the proper level.
For information on other Mercedes-Benz
approved products of equal specification,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
To provide important corrosion protection,
the solution must be at least 50% anticor-
rosion/antifreeze (equivalent to freeze
protection to approximately –35°F
[–37°C]).If you use a solution that is more than 55%
anticorrosion/antifreeze (freeze protec-
tion to approximately –49°F [–45°C]), the
engine temperature will increase due to
the lower heat transfer capability of the so-
lution. Therefore, do not use more than
this amount of anticorrosion/ antifreeze.
If the coolant level is low, water and
MB 325.0 Anticorrosion/Antifreeze
should be used to bring it up to the proper
level (have cooling system checked for
signs of leakage).
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality,
consult an authorized Mercedes-Benz
Center.
!Add premixed coolant solution only. Adding
water and MB 325.0 Anticorrosion/Antifreeze
separately from each other, could cause engine
damage not covered by the Mercedes-Benz Lim-
ited Warranty.