Page 316 of 505

315 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, only touch owner serviceable
components described in the Operator’s
Manual and 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 ignition is “on” and the engine is
turned manually
Page 318 of 505

317 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, the vehicle must have been sta-
tionary for at least 5 minutes with the
engine turned off.
with the engine not at operating tem-
perature yet, the vehicle must have
been stationary for at least 30 minutes
with the engine turned off.
iDo 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.
Page 319 of 505

318 Operation
Engine compartment
CLK 350 / CLK 550
1Oil dipstick
2Upper (max) mark
3Lower (min) mark
CLK 63 AMG
1Oil dipstick
2Upper (max) mark
3Lower (min) mark
To check the engine oil level with the oil
dipstick, do the following:
Open the hood (page 315).
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 319).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 472).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 394).
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).
Page 320 of 505

319 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 472) and (page 474).
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
(U.S. vehicles) or FSS (Canada vehicles). For a
listing of approved engine oils and oil filters,
refer to the Factory Approved Service Products
pamphlet 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 (U.S. vehicles) or FSS
(Canada vehicles), or changing of oil and oil filter
at change intervals longer than those called for
by the Maintenance System (U.S. vehicles) or
FSS (Canada vehicles) 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.
Page 355 of 505

354 Operation
Maintenance
Clearing the maintenance service
indicator message
The maintenance service indicator mes-
sage is automatically cleared after approx-
imately 30 seconds when you switch on
the ignition or when reaching the mainte-
nance service threshold while driving.
You can also clear it yourself.
1Reset button
Press reset button 1 on the
instrument cluster.The maintenance service indicator
message is cleared and the standard
display appears in the multifunction
display (
page 145).
Maintenance service term exceeded
If you have exceeded the suggested
maintenance service term, you will see the
following message in the multifunction
display:
Service A exceeded by XXXXX miles (km)
Service A exceeded by XXX days
In addition, a signal sounds when the
message appears.
Any authorized Mercedes-Benz Center will
reset the maintenance service indicator
following a completed maintenance
service.
iVehicles equipped with FSS (Flexible Ser-
vice S
ystem) only (Canada vehicles, depending
on vehicle production date):
FSS evaluates engine temperature, oil level,
vehicle speed, engine speed, distance driven
and the time elapsed since your last service
and calculates other maintenance service
work required.
The interval between maintenance services
depends on your driving habits. A gentle
driving style, moderate engine speeds and
the avoidance of short-distance trips will
lengthen the interval between services.
Page 356 of 505

355 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 38).
Press buttonè orÿ on the mul-
tifunction steering wheel repeatedly
until the standard display appears in
the multifunction display (
page 145).
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 by an
authorized 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
either your 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 dis-
play.
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 Warran-
ty.
Page 395 of 505

394 Practical hints
What to do if …?
When the message Check oil at next re-
fueling
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
approved oil specified in the Factory
Approved Service Products pamphlet.
Display symbolDisplay messagePossible cause/consequencePossible solution
:Check oil level
at next refuelingThe engine oil level has dropped to a
critical level.Check the engine oil level
(
page 317) and add oil as required
(
page 319).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
!The engine oil level warnings should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.
Page 473 of 505

472 Technical data
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 Ser-
vice Products pamphlet, or inquire at your
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 eyes or any open wounds.
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)
9.0 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)
9.3 US qt (8.5 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