323 Operation
Engine compartment
Engine compartment
Hood Opening
Warning!G
Do not pull the release lever while the vehi-
cle is in motion. Otherwise the hood could
be forced open by passing air flow.
This could cause the hood to come loose
and injure you and/or others.
Warning!G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature indicator 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
You could be injured when the hood is open
- even when the engine is turned off.
Parts of the engine can become very hot. To
prevent burns, let the engine cool off com-
pletely before touching any components on
the vehicle. Comply with all relevant safety
precautions.
Warning!G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or even restart
after the engine has been turned off. Stay
clear of fan blades.
Warning!G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnos-
tic socket) of the ignition system
with the engine running
while starting the engine
if the ignition is “on” and the engine is
turned manually.
325 Operation
Engine compartment
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
higher 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.
with the engine at operating tempera-
ture yet, the vehicle must have been
stationary for at least 5 minutes with
the engine turned off.
with the engine not at operating tem-
perature, the vehicle must have been
stationary for at least 30 minutes with
the engine turned off.CLK 350 / CLK 550
1Oil dipstick
2Upper (max) mark
3Lower (min) mark
!Do not use any special lubricant additives,
as these may damage the drive assemblies. Us-
ing special additives not approved by
Mercedes-Benz may cause damage not covered
by the Mercedes-Benz Limited Warranty. More
information on this subject is available at any
Mercedes-Benz Center.
326 Operation
Engine compartment
CLK 63 AMG
1Oil dipstick
2Upper (max) mark
3Lower (min) markTo check the engine oil level with the oil
dipstick, do the following:
Open the hood (page 323).
Pull out oil dipstick1.
Wipe oil dipstick1 clean.
Fully insert oil dipstick1 into the
dipstick guide tube.
Pull out oil dipstick1 again after
approximately 3 seconds to obtain ac-
curate reading.
The oil level is correct when it is be-
tween the lower (min) mark3 and
upper (max) mark2 of oil dipstick1.
If necessary, add engine oil.
For adding engine oil, see “Adding en-
gine oil” (
page 327).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 489).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 409).
iCLK 350:
The filling quantity between the upper and lower
marks on the oil dipstick is approximately
2.1 US qt. (2.0 l).
CLK 550 / CLK 63 AMG:
The filling quantity between the upper and lower
marks on the oil dipstick is approximately
1.6 US qt. (1.5 l).
327 Operation
Engine compartment
Adding engine oil
CLK 350 / CLK 550
1Filler cap
CLK 63 AMG
1Filler cap
Unscrew filler cap1 from filler neck.
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.
More information on engine oil can be
found in the “Technical data” section
(
page 489) and (page 491).
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 and oil filters
required for vehicles with Maintenance System.
For a listing of approved engine oils and oil fil-
ters, refer to the Factory Approved Service Prod-
ucts pamphlet (USA only) in your vehicle
literature portfolio, or contact an authorized
Mercedes-Benz Center.
Using engine oils and oil filters of specification
other than those expressly required for the
Maintenance System, or changing of oil and oil
filter at change intervals longer than those called
for by the Maintenance System will result in
engine or emission control system damage not
covered by the Mercedes-Benz Limited
Warranty.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and emis-
sion control system not covered by the
Mercedes-Benz Limited Warranty.
366 Operation
Maintenance
Calling up the maintenance service
indicator display
You can call up the maintenance service in-
dicator display at any time to check when
the next maintenance service is due.
Switch on the ignition (page 40).
Press buttonè orÿ on the
multifunction steering wheel
repeatedly until the standard display
appears in the multifunction display
(
page 147).
Press buttonkorjuntil the
maintenance service indicator display
with the service symbol9or½
and the service deadline appears in the
multifunction display.Resetting the maintenance service
indicator
In the event that the maintenance service
on your vehicle is not carried out at an au-
thorized Mercedes-Benz Center, you can
have the maintenance service indicator
reset. The automotive maintenance facility
carrying out the maintenance service will
find the information for resetting the
maintenance service indicator in the
maintenance-relevant information for your
vehicle. Such information is available from
any authorized Mercedes-Benz Center or
directly from Mercedes-Benz.iIf the battery is disconnected, the days of
disconnection will not be included in the count
shown by the maintenance service indicator. To
arrive at the true maintenance service deadline,
you will need to subtract these days from the
days shown in the maintenance service indicator
message or maintenance service indicator
display.
Do not confuse the maintenance service indica-
tor with the engine oil level indicator:.
iIf the maintenance service indicator was in-
advertently reset, have an authorized
Mercedes-Benz Center correct it.
Only reset if the proper maintenance service has
been performed. Resetting the system without
performing the proper service as called for by
the maintenance service indicator will result in
engine damage and/or other vehicle damage not
covered by the Mercedes-Benz Limited
Warranty.
409 Practical hints
What to do if …?
When the message Check oil level at
next refueling.
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 is at first in-
termittent and then remains on if the oil
level drops further.
Visually check for oil leaks. If there are no
obvious oil leaks, drive to the nearest ser-
vice station to refill the engine oil to the re-
quired level.
For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
Display symbolDisplay messagePossible cause/consequencePossible solution
:Check oil level
at next refueling
.
The engine oil level has dropped to a
critical level.Check the engine oil level
(
page 325) and add oil as required
(
page 327).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
!Engine oil level warnings should not be ig-
nored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz Limit-
ed Warranty.
489 Technical data
Fuels, coolants, lubricants, etc.
Fuels, coolants, lubricants, etc.
Capacities
Vehicle components and their respective
lubricants must match. Therefore only use
products tested and approved by
Mercedes-Benz.
Please refer to the Factory Approved
Service Products pamphlet (USA only), or
inquire at an authorized Mercedes-Benz
Center.
Warning!G
Comply with all valid regulations with
respect to handling, storing, and disposing
of service fluids. Otherwise you could
endanger persons or the environment.
Keep service fluids out of the reach of
children.
For health reasons, you should prevent
service fluids from coming into direct
contact with your skin and clothing.
If a service fluid is swallowed, contact a
physician immediately.
ModelCapacityFuels, coolants, lubricants, etc.
Engine with oil filterCLK 350
CLK 550
CLK 63 AMG8.5 US qt (8.0 l)
9.0 US qt (8.5 l)
9.3 US qt (8.8 l)Approved engine oils
Automatic transmissionCLK 350
CLK 550
CLK 63 AMG9.0 US qt (8.5 l)
9.5 US qt (9.0 l)
9.2 US qt (8.7 l)MB Automatic Transmission Fluid
Rear axleCLK 350
CLK 550
CLK 63 AMG1.16 US qt (1.1 l)
1.27 US qt (1.2 l)
1.27 US qt (1.2 l)Hypoid gear oil SAE 85 W 90
Fuchs Titan EG 5010D
491 Technical data
Fuels, coolants, lubricants, etc.
Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, only use
approved engine oils and oil filters
required for vehicles with Maintenance
System.
For a listing of approved engine oils and oil
filters, refer to the Factory Approved
Service Products pamphlet (USA only), or
contact an authorized Mercedes-Benz
Center.Engine oil additives
Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air
conditioning system.
Brake fluid
Only brake fluid approved by
Mercedes-Benz is recommended. Any
authorized Mercedes-Benz Center will
provide you with additional information.
!Using engine oils and oil filters of specifica-
tion other than those expressly required for the
Maintenance System, or changing of oil and oil
filter at change intervals longer than those called
for by the Maintenance System will result in
engine or emission control system damage not
covered by the Mercedes-Benz Limited
Warranty.
Please follow Maintenance System
recommendations for scheduled oil changes.
Failure to do so will result in engine or emission
control system damage not covered by the
Mercedes-Benz Limited Warranty.
!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.
!Never use R-12 (CFC) or mineral-based
lubricating oil. Otherwise damage to the system
will occur.
Warning!G
During vehicle operation, the boiling point of
the brake fluid is continuously reduced
through the absorption of moisture from the
atmosphere.
Under extremely strenuous operating condi-
tions, this moisture content can lead to the
formation of bubbles in the system, thus
reducing the system’s efficiency.
Therefore, the brake fluid must be replaced
regularly. Refer to your vehicle's Mainte-
nance Booklet for replacement interval.