2008 MERCEDES-BENZ CLK350 engine

473 Practical hints
Fuses
Opening fuse box
Open the driver’s door.
Insert flat, blunt object as a lever into
the edge of the fuse box cover1 at
the position indicated by the arrow.
Loosen fuse box cover1 from cockpit
using lever.
Using your hands, remove fuse box
cover1 rearward.
Closing fuse box
Attach fuse box cover1 in the front.
Fold fuse box cover1 in until it
engages.
Fuse box in engine compartment
The fuse box is located in the engine com-
partment on the driver’s side.
1Cover
2Screw
3Retainer
Removing cover
Twist screws2 90° counterclock-
wise.
Lift the rear of cover1.
Slide out retainer3 and remove
cover1 by pulling towards front.Opening fuse box
4Fuse box cover
5Clamps
With a dry cloth, remove any moisture
from the fuse box.
Release clamps5.
Remove fuse box cover4.

475 Technical data
Parts service
Warranty coverage
Identification labels
Layout of poly-V-belt drive
Engine
Rims and tires
Electrical system
Main dimensions and weights
Fuels, coolants, lubricants, etc.

479 Technical data
Identification labels
4Carpet
5VIN
Move the passenger seat to the rear as
far as possible.
Fold carpet4 in direction of arrow.
VIN5 is visible.6Emission control information label,
includes both federal and California
certification exhaust emission
standards
7VIN (lower edge of windshield)
8Engine number (engraved on engine)
iWhen ordering parts, please specify vehicle
identification and engine numbers.

481 Technical data
Engine
Engine
Model Coupe
CabrioletCLK 350 (209.356)1
CLK 350 (209.456)1
1The quoted data apply only to the standard vehicle. See an authorized Mercedes-Benz Center for the corresponding data of all special bodies and special equipment.
CLK 550 (209.372)1
CLK 550 (209.472)1CLK 63 AMG (209.477)1
Engine272273156
Mode of operation4-stroke engine,
gasoline injection4-stroke engine,
gasoline injection4-stroke engine,
gasoline injection
No. of cylinders688
Bore3.66 in (92.90 mm)3.85 in (98.00 mm)4.02 in (102.20 mm)
Stroke3.39 in (86.00 mm)3.56 in (90.50 mm)3.72 in (94.60 mm)
Total piston displacement213.5 cu in (3 498 cm3)333.25 cu in (5 461 cm3)378.8 cu in (6 208 cm3)
Compression ratio10.5:110.5:111.3:1
Output acc. to SAE J 1349268 hp / 6 000 rpm2
(200 kW / 6 000 rpm)
2Premium fuel required. Performance may vary with fuel octane rating.
382 hp / 6 000 rpm2
(285 kW / 6 000 rpm)
475 hp / 6 800 rpm2
(354 kW / 6 800 rpm)
Maximum torque acc. to SAE J
1349258 lb-ft/ 2 400 - 5 000 rpm
(350 Nm / 2 400 - 5 000 rpm)391 lb-ft / 2 800 - 4 800 rpm
(530 Nm /2 800 - 4 800 rpm)465 lb-ft / 5 000 rpm
(630 Nm / 5 000 rpm)
Maximum engine speed6300 rpm6500 rpm7200 rpm
Firing order1-4-3-6-2-51-5-4-2-6-3-7-81-5-4-2-6-3-7-8
Poly-V-belt2404 mm2404 mm (CLK coupe)
2 380 mm (CLK cabriolet)2360 mm

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.

492 Technical data
Fuels, coolants, lubricants, etc.
Premium unleaded gasolineFuel requirements
Only use premium unleaded fuel:

The octane number (posted at the
pump) must be 91 min. It is an average
of both the Research Octane Number
(RON) and the Motor Octane Number
(MON): (RON+MON)/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 co-solvents.
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.Warning!G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flame or smoking mate-
rials near gasoline!
Turn off the engine before refueling
Whenever you are around gasoline, avoid in-
haling fumes and skin or clothing contact,
extinguish all smoking materials.
Direct skin contact with fuels and the inha-
lation of fuel vapors can damage your
health.
!To maintain the engine’s durability and per-
formance, premium unleaded gasoline must be
used. If premium unleaded gasoline is not avail-
able and low octane fuel is used, follow these
precautions:

Have the fuel tank only partially filled with
unleaded regular gasoline and fill up with
premium unleaded gasoline 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 persons and no luggage.

Do not exceed 2/3 of maximum accelerator
pedal position if the vehicle is fully loaded or
operating in mountainous terrain.

493 Technical data
Fuels, coolants, lubricants, 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
deposits.
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
engine performance problems such as:

Warm-up hesitation

Unstable idle

Knocking/pinging

Misfire

Power lossIn areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles.
Refer to Factory Approved Service
Products pamphlet (USA only), or contact
an authorized Mercedes-Benz Center for a
listing of approved product(s). Follow
directions on product label.
!Do not blend other fuel additives with fuel.
This only results in unnecessary cost and may be
harmful to the engine operation.
Damage or malfunction resulting from poor fuel
quality or from blending additional fuel additives
other than those tested and approved by us for
use on Mercedes-Benz vehicles are not covered
by the Mercedes-Benz Limited Warranty.