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Adding engine oil
G
WARNING
If engine oil comes into contact with hot
engine parts, it may ignite and you could burn
yourself .Do not spill any engine oil on hot
engine parts. H
Environmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful
to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a
service system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
center.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R replacing engine oil and oil filters after
the interval for replacement specified by
the service system has been exceeded
R using engine oil additives.
! Do not add too much oil. adding too much
engine oil can result in damage to the
engine or to the catalytic converter. Have
excess engine oil siphoned off. Example: engine oil cap
X
Turn cap 0002counterclockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark
on the oil dipstick, add 0.55 US qt to
1.1 US qt (0.5 to 1.0 l)of engine oil.
X Replace cap 0002on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil
dipstick (Y page 261).
Further information on engine oil
(Y page 326). Checking and adding other service
products
Checking the coolant level G
WARNING
In order to avoid any potentially serious burns:
R 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 display indicates
that the coolant is overheated.
R do not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158 ‡(70 †). Allow the engine to
cool dow nbefore removing the cap. The
coolant reservoir contains hot fluid and is
under pressure. 262
Engine compartmentMaintenance and care
Page 328 of 334

You will usually find information about the fuel
grade on the pump. If you cannot find the
label on the pump, ask the staf
ffor
assistance.
i For further information, consult an
authorized Mercedes-Benz Center or visit
http://www.mbusa.com (USA only).
Information on refueling (Y page 146).
Additives
! Do not refuel with low-grade fuel and do
not use fuel additives that are not tested
and approved for Mercedes-Benz vehicles.
Damage to or malfunctions of the fuel
system may otherwise occur.
One of the main problems of poor fuel quality
is the forming of deposits that are created
during the gasoline combustion process.
Mercedes-Benz recommends that you use
branded fuels that have additives.
If you use fuels without these additives over
a longer period of time, carbon deposits may
build up. These deposits form at the inlet
valves and in the combustion chamber in
particular.
This could lead to engine problems, e.g.:
R longer engine warm-up phase
R uneven idle
R engine noise
R misfiring
R loss of power
Carbon deposits may form if the availability
of gasoline with relevant additives is
insufficient (in certain regions). In this case,
Mercedes-Benz recommends additives
approved for use in Mercedes-Benz vehicles;
see http://bevo.mercedes-benz.com.
For a list of approved products, consult an
authorized Mercedes-Benz Center. Comply
with the instructions for use on the product
label. Do not mix other fuel additives with fuel. This
causes unnecessary costs and could damage
the engine. Engine oil
Please bear the following in mind !
Never use engine oil or an oil filter of a
specification other than is necessary to
fulfill the prescribed service intervals. Do
not change the engine oil or oil filter in
order to achieve longer replacement
intervals than those prescribed. You could
otherwise cause engine damage or damage
to the exhaust gas aftertreatment.
Follow the instructions in the service
interval display regarding the oil change.
Otherwise, you may damage the engine and
the exhaust gas aftertreatment.
The engine oils are matched to the
performance of Mercedes-Benz engines and
service intervals. You should therefore only
use engine oils and oil filters that are
approved for vehicles with maintenance
systems.
For a list of approved engine oils and oil filters,
consult an authorized Mercedes-Benz
Center. Or visit the website
http://bevo.mercedes-benz.com.
The table shows which engine oils have been
approved for your vehicle. Model Engine
model MB
Approval
SLK 250
271 229.5
SLK 350
276
SLK 55 AMG
23 152
i
MB approval is indicated on the oil
containers.
23 Only SAE 0W-40/SAE 5W-40 engine oils may be used. 326
Service products and filling capacitiesTechnical data
Page 329 of 334

Filling capacities
The following values refer to an oil change
including the oil filter.
Model Capacity
SLK 250
5.8 US qt (5.5 l)
SLK 350
6.9 US qt (6.5 l)
SLK 55 AMG
10.0 US qt (9.5 l)
24 Additives
!
Do no tuse any additives in the engine oil.
This could damage the engine.
Engine oil viscosity Viscosity describes the flow characteristics
of a fluid. If an engine oil has a high viscosity,
this means that it is thick; a low viscosity
means that it is thin.
Select an engine oil with an SAE (viscosity)
classification suitable for the prevailing
outside temperatures. The table shows you
which SAE classifications are to be used. The
low-temperature characteristics of engine
oils can deteriorate significantly, e.g. as a
result of aging, soot and fuel deposits. It is
therefore strongly recommended that you
carry out regularo il changes using an
approved engine oil with the appropriate SAE
classification. Brake fluid
G
WARNING
Over a period of time, the brake fluid absorbs
moisture fro mthe air; this lowers its boiling
point.
If the boiling point of the brake fluid is too low,
vapor pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This would impair braking
efficiency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change
intervals can be found in the Maintenance
Booklet.
Only use brake fluid approved by Mercedes-
Benz.I nformation abou tapproved brake fluid
can be obtained at any qualified specialist
workshop or on the Internet at
http://bevo.mercedes-benz.com. Coolant
Important safety notes G
WARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when
handling antifreeze.
If antifreeze comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any antifreeze on hot
engine parts.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications
for Service Products, MB Specifications for
Service Products 310.1, e.g. on the
Internet at
http://bevo.mercedes-benz.com. Or
contact a qualified specialist workshop.
24 Including external oil cooler. Service products and filling capacities
327Technical data Z