291 Operation
Engine compartment
Adding engine oil
1Filler cap
Unscrew filler cap1 from filler neck.
Be careful not to overfill with oil.
Add engine oil as required. Be careful
not to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
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.
!Only use approved engine oils. For a
listing of a approved engine oils, refer
to the Factory Approved Service Prod-
u c t s p a m p hl e t i n y o u r v e h i c l e l i t e r a t u r e
portfolio.
In addition, check the oil filler cap for
important information pertaining to the
engine oil needing to meet a specific
Mercedes-Benz specification (e.g. MB
229.5). If such information is printed
on the oil filler cap, only use an engine
oil from the list of approved engine oils
in the Factory Approved Service Prod-
ucts pamphlet that meets the specifi-
cation indicated on the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.
!Excess oil must be siphoned or drained
off. It could cause damage to the en-
gine and catalytic converter not cov-
ered by the Mercedes-Benz Limited
Warranty.
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303 Operation
Maintenance
Calling up the service indicator
Switch on ignition.
The standard display of the control sys-
tem appears (
page 129).
Press button k or j on the mul-
tifunction steering wheel until FSS indi-
cator with the service symbol 9 or
´ and the service deadline appears
in the multifunction display.
Resetting the service indicator
In the event that the service on your vehi-
cle is not carried out by an authorized
Mercedes-Benz Center, you can reset the
service indicator yourself.
Switch on ignition.
The standard display of the control sys-
tem appears (
page 129).
Press button k or j on the mul-
tifunction steering wheel until the FSS
indicator with the service symbol 9
or ´ and the service deadline ap-
pears in the multifunction display.
Press reset button to the left in the in-
strument cluster for about three sec-
onds.
This message appears in the multifunc-
tion display:Service interval...
To reset:
Press reset button
for 3 seconds
To confirm, press reset button until you
hear a signal.
The service indicator now displays the
reset interval.
iIf the battery is disconnected, the days
of disconnection will not be included in
the count shown by the service indica-
tor. To arrive at the true service dead-
line, you will need to subtract these
days from the days shown in the ser-
vice indicator.
Do not confuse the service indicator
with the engine oil level indicator :.
iIf the service indicator was inadvertent-
ly reset, have a Mercedes-Benz Center
correct it.
Only reset if the proper service has
been performed. Resetting the system
without performing proper service as
called for by the FSS will cause the FSS
to incorrectly determine the next ser-
vice interval which will result in engine
damage not covered by the
Mercedes-Benz Limited Warranty.
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332 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
:
USA only:Add 1 qt. engine oil
when next refuelingCanada only:Add 1 liter engine oil
when next refueling
The engine oil level is too low.
Add engine oil (
page 291) and check
the engine oil level (
page 289).
Engine oil level
Reduce oil level!
You have added too much engine oil.
There is a risk of damaging the engine or
the catalytic converter.
Have oil siphoned or drained off. Ob-
serve all legal requirements with re-
spect to its disposal.
Engine oil level
Stop, engine off!
There is no oil in the engine. There is a
danger of engine damage.
Carefully bring the vehicle to a halt as
soon as possible.
Turn off the engine.
Add engine oil (
page 291) and check
the engine oil level (
page 289).
ProCarManuals.com
333 Practical hints
What to do if …?
When the message
Add 1 qt. engine oil
when next refueling
(Canada:
1 liter
)
appears while the engine is running and at
operating temperature, the engine oil level
has dropped to approximately 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, drive to the nearest ser-
vice station where the engine oil should be
topped to the required level with an ap-
proved oil.
Display symbol
Display message
Possible cause
Possible solution
:
Engine oil
Visit workshop!
It may be that there is water in the engine
oil.
Have the engine oil checked.
Engine oil level
Visit workshop!
The engine oil has dropped to a critical
level.
Check the engine oil level
(page 289) and add oil as required
(page 291).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
The measuring system is malfunctioning.
Have the measuring system checked
by an authorized Mercedes-Benz
Center.!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
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410 Technical dataFuels, coolants, lubricants, etc.
Fuels, coolants, lubricants, etc.CapacitiesVehicle components and their respective
lubricants must match. Therefore only use
brands tested and approved by
Mercedes-Benz.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
CLK 320
CLK 500
CLK 55 AMG
8.5 US qt (8.0 l)
8.0 US qt (7.5 l)
9.0 US qt (8.5 l)
Approved engine oils
Automatic transmission
CLK 320
CLK 500
CLK 55 AMG
8.0 US qt (7.5 l)
9.3 US qt (8.7 l)
9.3 US qt (8.7 l)
MB Automatic Transmission Oil
Rear axle
CLK 320
CLK 500
CLK 55 AMG
1.28 US qt (1.2 l)
1.5 US qt (1.4 l)
1.5 US qt (1.4 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. 3.0 oz (85 g) each
High temperature roller bearing grease
Brake system
0.64 US qt (0.6 l)
MB Brake Fluid (DOT 4+)
ProCarManuals.com
412 Technical dataFuels, coolants, lubricants, etc.Engine oils
Engine oils are specifically tested for their
suitability in our engines. Therefore, only
use engine oils approved by
Mercedes-Benz. Information on approved
engine oils is available in the Factory Ap-
proved Service Products pamphlet, or at
your authorized Mercedes-Benz Center.Please follow FSS recommendations for
scheduled oil changes. Failure to do so
could result in engine damage not covered
by the Mercedes-Benz Limited Warranty.
Engine oil additives
Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from
blending oil additives are not covered by
the Mercedes-Benz Limited Warranty.Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air condition-
ing system.Never use R-12 (CFC) or mineral-based lu-
bricating oil. Otherwise damage to the
system will occur.
Brake fluid
During vehicle operation, the boiling point
of the brake fluid is continuously reduced
through the absorption of moisture from
the atmosphere. Under extremely strenu-
ous operating conditions, this moisture
content can lead to the formation of bub-
bles in the system, thus reducing the sys-
tem’s efficiency.
Therefore, the brake fluid must be re-
placed every two years, preferably in the
spring.
Only brake fluid approved by
Mercedes-Benz is recommended. Your au-
thorized Mercedes-Benz Center will pro-
vide you with additional information.
!Always check the oil filler cap
(page 291) for important information
pertaining to the engine oil needing to
meet a specific Mercedes-Benz specifi-
cation (e.g. MB 229.5). If such informa-
tion is printed on the oil filler cap, only
use an engine oil from the list of ap-
proved engine oils in the Factory Ap-
proved Service Products pamphlet that
meets the specification indicated on
the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.
ProCarManuals.com
413 Technical data
Fuels, coolants, lubricants, etc.
Premium unleaded gasoline
Fuel requirements
Only use premium unleaded gasoline
meeting ASTM standard D 439:
The octane number (posted at the
p um p) m us t be 91 mi n. It i s an a vera ge
of both the Research (R) octane num-
ber and the Motor (M) octane number:
(R+M) / 2). This is also known as the
ANTI-KNOCK INDEX.
Unleaded gasoline containing oxygenates
such as ethanol, IPA, IBA and TBA can be
used provided the ratio of any one of these
oxygenates to gasoline does not exceed
10%; MTBE not to exceed 15%.
The ratio of methanol to gasoline must not
exceed 3% plus additional cosolvents.
Using mixtures of ethanol and methanol is
not allowed. Gasohol, which contains 10%
ethanol and 90% unleaded gasoline, can be
used.
These blends must also meet all other fuel
requirements, such as resistance to spark
knock, boiling range, vapor pressure, etc.
Gasoline additives
A major concern among engine manufac-
turers is carbon build-up caused by gaso-
line. Mercedes-Benz recommends only the
use of quality gasoline containing additives
that prevent the build-up of carbon depos-
its.
After an extended period of using fuels
without such additives, carbon deposits
can build up especially on the intake valves
and in the combustion area, leading to en-
gine performance problems such as:
Warm-up hesitation
Unstable idle
Knocking/pinging
Misfire
Power loss
Do not blend any specific fuel additives
with fuel. This only results in unnecessary
cost and may be harmful to the engine op-
eration.
!To maintain the engine’s durability and
performance, premium unleaded gaso-
l i n e m u s t b e u s e d . I f p r e m i u m u n l e a d e d
is not available and low octane fuel is
used, follow these precautions:
Have the fuel tank only partially
filled with unleaded regular and fill
up with premium unleaded as soon
as possible.
Avoid full throttle driving and abrupt
acceleration.
Do not exceed an engine speed of
3 000 rpm if the vehicle is loaded
with a light load such as two per-
sons and no luggage.
Do not exceed
2⁄3 of maximum ac-
celerator pedal position if the vehi-
cle is fully loaded or operating in
mountainous terrain.
ProCarManuals.com
414 Technical dataFuels, coolants, lubricants, etc.Damage or malfunctions resulting from
poor fuel quality or from blending specific
fuel additives are not covered by the
Mercedes-Benz Limited Warranty.Coolants
The engine coolant is a mixture of water
and anticorrosion / antifreeze, which
provides:
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
coolant 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 Service Booklet for replace-
ment interval.
Coolant system design and coolant used
stipulate the replacement interval. The
replacement interval published in the
Service Booklet is only applicable if
MB 325.0 anticorrosion/antifreeze solu-
tion or other Mercedes-Benz approved
products of equal specification (see Facto-
ry Approved Service Products pamphlet)
are used to renew the coolant concentra-
tion or bring it back up to the proper level.To provide important corrosion protection,
the solution must be at least 45% anticor-
rosion/antifreeze (equivalent to freeze
protection to approx. -22°F [-30°C]). If you
use a solution that is more than 55% anti-
corrosion/antifreeze (freeze protection to
approx. -49°F [-45°C]), the engine temper-
ature will increase due to the lower heat
transfer capability of the solution. There-
fore, do not use more than this amount of
anticorrosion/antifreeze.
If the coolant level is low, water and MB
Anticorrosion /Antifreeze should be used
to bring it up to the proper level (have cool-
ing system checked for signs of leakage).
Please make sure the mixture is in accor-
dance with label instructions.
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, con-
sult your authorized Mercedes-Benz
Center.
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