2007 MERCEDES-BENZ CLK63AMG engine

314 Operation
At the gas station
Check regularly and before a long trip
Engine compartment (CLK 550, example)
1Coolant level
2Brake fluid (fuse box cover removed)
3Windshield washer and headlamp
cleaning system*Coolant
For normal replenishing, use water (pota-
ble water quality). For more information,
see “Coolant” (
page 320) and see “Fu-
els, coolants, lubricants, etc.”
(
page 472).
Brake fluid
Removing fuse box cover (
page 457).Windshield washer and headlamp
cleaning system*
For more information on filling up the
washer reservoir, see “Windshield washer
system and headlamp cleaning system*”
(
page 322).
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 317).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
“Replacing bulbs” (
page 427).
For more information, see “Exterior lamp
switch” (
page 54).
Tire inflation pressure
For more information, see “Recommended
tire inflation pressure” (
page 331).
iOpening the hood, see (page 315).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Center immediately.
Do not add brake fluid as this will not solve the
problem. For more information, see also “Practi-
cal hints” (
page 368).

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

316 Operation
Engine compartment
The hood lock release lever is located to
the left of the steering wheel under the
dashboard.
1Hood lock release lever
Pull lever 1 downwards.
The hood is unlocked.2Lever for opening the hood
Push lever 2 on the hood upwards.
Pull up on the hood and then release it.
The hood will be automatically held
open at shoulder height by gas-filled
struts.Closing
Let the hood drop from a height of
approximately 1 ft (30 cm).
The hood will lock audibly.
Check to make sure 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.
!To avoid damage to the windshield wipers or
hood, never open the hood if the wiper arms are
folded forward away from the windshield.
Warning!G
When closing the hood, use extreme caution
not to catch hands or fingers.
Be careful that you do not close the hood on
anyone.
Make sure that the hood is securely en-
gaged before driving off. Do not continue
driving if the hood can no longer engage af-
ter an accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others.

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.

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).

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.

320 Operation
Engine compartment
Coolant
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
compartment.
1Coolant expansion tank
2CapUsing a rag, turn cap2 slowly
approximately one half turn counter-
clockwise to release any excess pres-
sure.
Continue turning the cap2 counter-
clockwise and remove it.
The coolant level is correct if the level

for cold coolant: reaches the marking
(plastic bridge) inside the reservoir

for warm coolant: is approx. 0.6 in
(1.5 cm) higher
Add coolant as required.
Replace and tighten cap2.
More information on coolant can be found
in the “Technical data” section
(
page 477).
Warning!G
In order to avoid any 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 indicator
indicates that the coolant is overheated.

Do not remove pressure cap on coolant
reservoir if the coolant temperature is
above 158°F (70°C). Allow the coolant
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 1/2 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.

321 Operation
Engine compartment
Battery
Your vehicle’s battery is located in the
engine compartment on the right-hand
side (
page 447).
The battery should always be sufficiently
charged in order to achieve its rated
service life. Refer to Maintenance Booklet
for battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more
frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
Warning!G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.