291 Operation
Engine compartment
Checking engine oil level with the oil
dipstick, SLK 350
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 five minutes with
the engine turned off.
with the engine not at operating tem-
perature, the vehicle must have been
stationary for at least 30 minutes with
the engine turned off.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 287).
Pull out oil dipstick1.
Wipe oil dipstick1 clean.
Fully insert oil dipstick1 into the
dipstick guide tube.
Pull out oil dipstick1 again after
approximately three seconds to obtain
accurate 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 292).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 422).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(page 348).iThe filling quantity between the upper
and lower marks on the oil dipstick is
approximately 2.1 US qt. (2.0 l).
292 OperationEngine compartmentAdding engine oil
Only use approved engine oils and oil fil-
ters required for vehicles with Mainte-
nance System (U.S. vehicles) or FSS
(Canada vehicles). For a listing of approved
engine oils and oil filters, refer to the Fac-
tory Approved Service Products pamphlet
in your vehicle literature portfolio, or con-
tact an authorized Mercedes-Benz Center.
Using engine oils and oil filters of specifica-
tion other than those expressly required
for the Maintenance System (U.S. vehi-
cles) or FSS (Canada vehicles), or changing
of oil and oil filter at change intervals long-
er than those called for by the Mainte-
nance System (U.S. vehicles) or FSS
(Canada vehicles) will result in engine dam-
age not covered by the Mercedes-Benz
Limited Warranty.
SLK 3501Filler capSLK 55 AMG1Filler 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.
For more information on engine oil, see the
“Technical data” section (
page 422) and
(
page 424).!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.
330 OperationMaintenanceClearing the maintenance service indicator
The maintenance service indicator is auto-
matically cleared after 30 seconds.
You can also clear it yourself.
Press reset buttonJ(
page 24) for
clearing the maintenance service indi-
cator.
The maintenance service indicator is
cleared and the standard display menu
appears in the multifunction display
(
page 122).
Maintenance service term exceeded
If you have exceeded the suggested main-
tenance service term, you will see the fol-
lowing message in the multifunction
display:Service A exceeded by XXXXX miles (km)
Service A exceeded by XXX days
Service A exceeded by X dayIn addition, a signal sounds when the mes-
sage appears.
Any authorized Mercedes-Benz Center will
reset the maintenance service indicator
following a completed maintenance
service.Calling up the maintenance service
indicator
Switch on the ignition (
page 35).
The standard display menu appears in
the multifunction display (page 122).
Press buttonjork repeatedly
on the multifunction steering wheel un-
til the maintenance service
indicator9 appears in the multi-
function display (
page 118).
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.
Do not confuse the maintenance ser-
vice indicator with the engine oil level
indicator:.
360 Practical hintsWhat to do if …When the message
Add 1 qt.
(Canada:
1 liter
) engine oil when next
refueling (SLK 55 AMG) or
Check oil
level when next refueling (SLK 350)
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 ap-
proved oil specified in the Factory
Approved Service Products pamphlet.
Display symbol
Display message
Possible cause
Possible solution
:
USA only:Add 1 qt. engine oil
when next refuelingCanada only:Add 1 liter engine oil
when next refueling
SLK 55 AMG only:
The engine oil level is too low.
Add engine oil (
page 292) and check the
engine oil level (page 288).
Check oil level
when next refueling
SLK 350 only:
The engine oil level has dropped to
a critical level.
Check the engine oil level (
page 288) and
add engine oil as required (page 292).
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 displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
361 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
:
Engine oil level
Stop, engine off
SLK 55 AMG only:
There is no oil in the engine. There
is a danger of engine damage.
Carefully bring the vehicle to a halt as soon
as possible.
Turn off the engine.
Add engine oil (
page 292) and check the
engine oil level (page 288).
Engine oil level
Visit workshop
SLK 55 AMG only:
The measuring system is malfunc-
tioning.
Have the measuring system checked by an
authorized Mercedes-Benz Center.
Engine oil level
Reduce oil level
SLK 55 AMG only:
You have added too much engine
oil. There is a risk of damaging the
engine or the catalytic converter.
Have oil siphoned or drained off.
Observe all legal requirements with respect
to its disposal.
Engine oil
Visit workshop
SLK 55 AMG only:
There may be water in the engine
oil.
Have the engine oil checked.
422 Technical dataFuels, coolants, lubricants, etc.CapacitiesVehicle 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
authorized Mercedes-Benz Center.
Model
Capacity
Fuels, coolants, lubricants etc.
Engine with oil filter
SLK 350
8.5 US qt (8.0 l)
Approved engine oils
SLK 55 AMG
8.5 US qt (8.0 l)
Automatic transmission*
SLK 350
10.4 US qt (9.8 l)
MB Automatic Transmission Fluid
SLK 55 AMG
10.4 US qt (9.8 l)
Manual transmission
SLK 350
1.6 US qt (1.5 l)
MB Manual Transmission Oil
Rear axle
SLK 350
1.2 US qt (1.1 l)
Hypoid gear oil SAE 85 W 90
SLK 55 AMG
1.3 US qt (1.2 l)
Power steering
SLK 350
1.1 US qt (1.0 l)
MB Power Steering Fluid (Pentosin CHF 11S)
SLK 55 AMG
1.1 US qt (1.0 l)
Front wheel hubs
approx. 2.1oz (60g) each
High temperature roller bearing grease
Brake system
0.5 US qt (0.5 l)
MB Brake Fluid (DOT 4)
Cooling system
SLK 350
approx.11.2 US qt (10.2 l)
MB 325.0 Anticorrosion/Antifreeze Agent
SLK 55 AMG
approx. 11.7 US qt (11.1 l)
424 Technical dataFuels, 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 re-
quired 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, or
contact an authorized Mercedes-Benz
Center.
Using engine oils and oil filters of specifica-
tion other than those expressly required
for the Maintenance System (U.S. vehi-
cles) or FSS (Canada vehicles), or changing
of oil and oil filter at change intervals long-
er than those called for by the
Maintenance System (U.S. vehicles) or
FSS (Canada vehicles) will result in engine
damage not covered by the
Mercedes-Benz Limited Warranty.Please follow Maintenance System (U.S.
vehicles) or FSS (Canada vehicles) recom-
mendations for scheduled oil changes.
Failure to do so will 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 are used in the air con-
ditioning 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 replaced every two years, prefera-
bly in the spring. Only brake fluid approved
by Mercedes-Benz is recommended. Your
authorized Mercedes-Benz Center will pro-
vide you with additional information.
425 Technical data
Fuels, coolants, lubricants, etc.
Premium unleaded gasoline
Fuel 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 (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 only recommends 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
!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
3 000 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.