2008 MERCEDES-BENZ SLK280 engine coolant

300 Operation
Engine compartment
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
“Technical data” (
page 451) and
(
page 453).
Transmission fluid level*
Vehicles with automatic transmission*:
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 level
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking the coolant level,

the vehicle must be parked on level
ground

the coolant temperature must be
below 158°F (70°C)
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and
emission control system not covered by the
Mercedes-Benz Limited Warranty.
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 gauge indi-
cates that the coolant is overheated.

Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°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 1/2turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out
under pressure.

Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.

301 Operation
Engine compartment
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
SLK 350 (example illustration)
1Coolant expansion tank
2Cap
3Marking bar in the expansion tank
Using a rag, turn cap2 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning cap2 counterclock-
wise and remove it.
The coolant level is correct if the level

for cold coolant: reaches marking
bar3 in expansion tank1

for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap2.
For more information on coolant, see
“Coolants” (
page 456).Windshield washer system and
headlamp cleaning system*
The windshield washer reservoir is located
on the passenger side of the engine com-
partment.
SLK 350 (example illustration)
1Cap for windshield washer reservoir
Fluid for the windshield washer system
and the headlamp cleaning system* is
supplied from the windshield washer
reservoir. It has a capacity of
approximately 7.4 US qt (7 l).

371 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
ÊThis message will appear whenever
the trunk lid is open.Close the trunk lid.
OYou are driving with the hood open.Risk of accident!
Stop the vehicle in a safe location or as soon
as it is safe to do so.
Apply the parking brake (page 59).
Close the hood (page 294).
JYou are driving with one or more
doors open.Close the doors.
•The cooling fan for the coolant is
malfunctioning.Observe the coolant temperature display
(
page 127).
If the coolant temperature is below 120°C,
you may continue driving to the nearest
specialist workshop.
Avoid heavy loads on the engine (e.g. by
driving uphill) as well as stop-and-go traffic.
Have the fan replaced as soon as possible.

374 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop, turn engine
off
.
The coolant is too hot.
Among other possible causes,
the poly-V-belt could be broken.Stop the vehicle in a safe location or as soon as it is
safe to do so.
Turn off the engine.
Apply the parking brake (page 59).
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise, the engine will
overheat due to an inoperative water pump which
may result in damage to the engine. Contact an
authorized Mercedes-Benz Center.
If it is intact:
Wait for the message to disappear before restarting
the engine.
Doing otherwise could result in serious engine
damage that is not covered by the Mercedes-Benz
Limited Warranty.
(Continued on next page)

375 Practical hints
What to do if …
During severe operating conditions, e.g.
stop-and-go traffic, the coolant tempera-
ture may rise close to 248°F (120°C).
Display symbolDisplay messagePossible cause/consequencePossible solution
Observe the coolant temperature display
(
page 127).
If the temperature rises again:
Contact an authorized Mercedes-Benz
Center immediately.
Warning!G
Driving when your engine is overheated can
cause some fluids which may have leaked
into the engine compartment to catch fire.
You could be seriously burned.
Steam from an overheated engine can cause
serious burns and can occur just by opening
the hood. Stay away from the engine if you
see or hear steam coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
!The engine should not be operated with the
coolant temperature above 248°F (120°C).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty.

376 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
/Top Up Coolant
See Operator’s ManualThe coolant level is too low.Add coolant (page 300).
Comply with all warnings while doing so.
If you have to add coolant frequently,
have the cooling system checked by an au-
thorized Mercedes-Benz Center.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with this message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz
Limited Warranty. Do not drive without sufficient
amount of coolant in the cooling system. The
engine will overheat, causing major engine
damage.

377 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
±Display Malfunction
Drive To WorkshopCertain electronic systems are un-
able to relay information to the con-
trol system. The following systems
may have failed:

Coolant temperature display

Tachometer

Cruise control display
Have the electronic systems checked by an
authorized Mercedes-Benz Center.
NCheck oil level
when next refueling
.
SLK 280 and SLK 350 only:
The engine oil level has dropped to
a critical level.Check the engine oil level (page 296) and
add engine oil as required (
page 299).
If you must add engine oil frequently, have
the engine checked for possible leaks.

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