179 Operation
Engine compartment
Adding engine oil
SLK 230 Kompressor1Oil dipstick
2Filler cap
Unscrew filler cap2 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 cap2 back on filler neck.
SLK 320, SLK 32 AMG1Oil dipstick
2Filler cap
Unscrew filler cap2 from filler neck.
Add engine oil as required. Be careful
not to overfill with oil.
!Only use approved engine oils. For a
listing of approved engine oils, refer to
the Factory Approved Service Products
pamphlet in your vehicle literature port-
folio.
In addition, check the oil filler cap for
important information pertaining to the
engine oil needing to meet a specific
Mercedes-Benz specification (e.g. MB
229.5). If such information is printed
on the oil filler cap, only use an engine
oil from the list of approved engine oils
in the Factory Approved Service Prod-
ucts pamphlet that meets the specifi-
cation indicated on the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine 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 catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
180 OperationEngine compartmentBe careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap2 back on filler neck.
More information on engine oil can be
found in the “Technical data” section
(
page 277) and (
page 279).
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 transmission.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 compart-
ment.
!Excess oil must be siphoned or drained
off. It could cause damage to the
engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
Warning!
G
In order to avoid any possibly 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 gauge indi-
cates that the coolant is overheated.
Do not remove pressure cap on coolant
reservoir if engine temperature is above
194°F (90°C). Allow engine 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 ½ 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.
191 Operation
Maintenance
Service term exceeded
If you have exceeded the suggested
service term:
the9 or´ appears in the
display2 for 30 seconds and a signal
sounds after switching on the ignition.
it is preceded by a “-” (minus symbol)
The Mercedes-Benz Center will reset the
service indicator following a completed
service.
Calling up the service indicator
Within one second press knob1
(page 190) twice.
The service symbol and the service
deadline appear in the display2.
Resetting the service indicator
In the event that the service on your vehi-
cle is not carried out by an authorized
Mercedes-Benz Center, you can reset the
service indicator yourself.
Switch ignition on (key in steering lock
position 2) and immediately press
knob1 (
page 190) twice within
1 second.
The present status for days or distance
is displayed.
Within ten seconds turn key in steering
lock to position0.
Press and hold knob1 while turning
key in steering lock to position2 again.
The present status for days and dis-
tance is displayed once more.
Continue to hold knob1 until you
hear a signal.
Release knob1.
The service indicator now displays the
reset interval.
iIf the service indicator was inadvertent-
ly reset, have a Mercedes-Benz Center
correct it.
Only reset if the proper service has
been performed. Resetting the system
without performing proper service as
called for by the FSS will cause the FSS
to incorrectly determine the next ser-
vice interval which will result in engine
damage not covered by the Mer-
cedes-Benz Limited Warranty.
If the battery is disconnected, the days
of disconnection will not be included in
the count shown by the service indica-
tor. To arrive at the true service dead-
line, you will need to subtract these
days from the days shown in the ser-
vice indicator.
Do not confuse the service indicator
with the engine oil level indicator:.
206 Practical hintsWhat to do if …When the low engine oil level warning lamp
does not go out after starting the engine,
or comes on while the engine is running
and at operating temperature, the engine
oil level has dropped to approximately the
minimum mark on the dipstick.When this occurs, the warning lamp will
first come on intermittently and then stay
on if the oil level drops further.
If no oil leaks are noted, continue to drive
to the nearest service station where the
engine oil should be topped to the “full”
mark on the dipstick with an approved oil.Problem
Possible cause
Suggested solution
_
The red telescoping steering
column* warning lamp remains
lit after starting the engine.
The adjustable steering column is not locked
properly.
Lock the steering column
(page 34).
W
The yellow low windshield and
headlamp* washer system fluid
level warning lamp remains lit af-
ter starting the engine or lights
up while driving.
The fluid level has dropped to about
1/3 of
total reservoir capacity.
Add washer fluid (
page 184).
N
The yellow low engine oil level
warning lamp remains lit after
starting the engine or comes on
while driving.
The engine oil level has sunk to the minimum
level.
Check the engine oil level
(page 175) and add oil as required
(page 179).
If you must add engine oil frequently,
have the engine checked for possible
leaks.!The low engine oil level warning light
should not be ignored. Extended driv-
ing with the light illuminated could re-
sult in serious engine damage that is
not covered by the Mercedes-Benz
Limited Warranty.
277 Technical data
Fuels, coolants, lubricants etc.
Fuels, coolants, lubricants etc.
CapacitiesVehicle components and their respective
lubricants must match. Therefore use only
brands tested and approved by Mer-
cedes-Benz.Please refer to the Factory Approved Ser-
vice Products pamphlet, or inquire at your
Mercedes-Benz Center.
Model
Capacity
Fuels, coolants, lubricants etc.
Engine with oil filter
SLK 230 Kompressor
6.1 US qt (5.5 l)
Recommended engine oils
SLK 320
SLK 32 AMG
8.5 US qt (8.0 l)
Automatic transmission*
8.5 US qt (8.0 l)
MB Automatic Transmission Oil
Manual transmission
SLK 230 Kompressor
1.6 US qt (1.5 l)
MB Manual Transmission Oil
SLK 320
1.9 US qt (1.8 l)
Rear axle
1.4 US qt (1.3 l)
Hypoid gear oil SAE 90, 85 W 90
Power steering
approx. 1.1 US qt (1.0 l)
MB Power Steering Fluid
Front wheel hubs
approx. 1.5 oz (43 g) each
High temperature roller bearing grease
Brake system
0.5 US qt (0.5 l)
MB Brake Fluid (DOT 4)
Cooling system
SLK 230 Kompressor
approx. 9.8 US qt (9.3 l)
MB 325.0 Anticorrosion/Antifreeze Agent
SLK 320
approx. 11.8 US qt (11.2 l)
SLK 32 AMG
approx. 15.3 US qt (14.5 l)
279 Technical data
Fuels, coolants, lubricants etc.
Engine oils
Engine oils are specifically tested for their
suitability in our engines. Therefore, use
only engine oils recommended by
Mercedes-Benz. Information on approved
engine oils is available in the Factory Ap-
proved Service Products pamphlet, or at
your authorized Mercedes-Benz Center.Please follow FSS or Service Booklet rec-
ommendations for scheduled oil changes.
Failure to do so could result in engine dam-
age not covered by the Mercedes-Benz
Limited Warranty.
Engine oil additives
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.Air conditioning refrigerant
R-134a (HFC) refrigerant and special
PAG lubricating oil is used in the air condi-
tioning system.Never use R-12 (CFC) or mineral-based
lubricating oil, otherwise damage to the
system will occur.
Brake fluid
During vehicle operation, the boiling point
of the brake fluid is continuously reduced
through the absorption of moisture from
the atmosphere. Under extremely strenu-
ous operating conditions, this moisture
content can lead to the formation of bub-
bles in the system, thus reducing the sys-
tem’s efficiency.
Therefore, the brake fluid must be re-
placed every two years, preferably in the
spring.
Only brake fluid approved by
Mercedes-Benz is recommended. Your au-
thorized Mercedes-Benz Center will pro-
vide you with additional information.
!Always check the oil filler cap
(page 171) for important informa-
tion pertaining to the engine oil need-
ing to meet a specific Mercedes-Benz
specification (e.g. MB 229.5). If such
information is printed on the oil filler
cap, only use an engine oil from the list
of approved engine oils in the Factory
Approved Service Products pamphlet
that meets the specification indicated
on the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.
280 Technical dataFuels, coolants, lubricants etc.Premium unleaded gasoline
Fuel requirements
Use only premium unleaded gasoline
meeting ASTM standard D 439:
The octane number (posted at the
pu mp ) m ust b e 91 m i n. It is an a ve ra ge
of both the Research (R) octane num-
ber and the Motor (M) octane number:
(R+M) / 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 cosolvents.
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.
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 depos-
its.
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 loss
Do not blend any specific fuel additives
with fuel. This only results in unnecessary
costs and may be harmful to engine opera-
tion.
!To maintain the engine’s durability and
performance, premium unleaded gaso-
line must be used. If premium unleaded
is not available and low octane fuel is
used, follow these precautions:
Have the fuel tank only partially
filled with unleaded regular and fill
up with premium unleaded as soon
as possible.
Avoid full throttle driving and abrupt
acceleration.
Do not exceed an engine speed of
3000 rpm if the vehicle is loaded
with a light load such as two per-
sons and no luggage.
Do not exceed
2/3of maximum ac-
celerator pedal position if the vehi-
cle is fully loaded or operating in
mountainous terrain.
281 Technical data
Fuels, coolants, lubricants etc.
Damage or malfunctions resulting from
poor fuel quality or from blending specific
fuel additives are not covered by the
Mercedes-Benz Limited Warranty.Coolants
The engine coolant is a mixture of water
and anticorrosion / antifreeze, which pro-
vides:
Corrosion protection
Freeze protection
Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -22°F (-30°C) and corro-
sion protection.
If the antifreeze mixture is effective to
-22°F (-30°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).The coolant solution must be used
year-round to provide the necessary corro-
sion protection and increase boil over-pro-
tection. Refer to Service Booklet for
replacement interval.
Coolant system design and coolant used
stipulate the replacement interval. The re-
placement interval published in the Ser-
vice Booklet is only applicable if MB 325.0
anticorrosion/antifreeze solution or other
Mercedes-Benz approved products of
equal specification (see Factory Approved
Service Products pamphlet) are used to re-
new the coolant concentration or bring it
back up to the proper level.
To provide important corrosion protection,
the solution must be at least 45% anticor-
rosion/antifreeze (equivalent to freeze
protection to approx. -22°F [-30°C]). If you
use a solution that is more than 55% anti-
corrosion/antifreeze (freeze protection to
approx. -49°F [-45°C]), the engine temper-
ature will increase due to the lower heat transfer capability of the solution. There-
fore, do not use more than this amount of
anticorrosion/antifreeze.
If the coolant level is low, water and MB
Anticorrosion /Antifreeze should be used
to bring it up to the proper level (have cool-
ing system checked for signs of leakage).
Please make sure the mixture is in accor-
dance with label instructions.
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality, con-
sult your authorized Mercedes-Benz
Center.