Engine coolant MERCEDES-BENZ SLK350 2007 R171 User Guide

290 Operation
Driving instructions
!Excessive coolant temperature triggers a
warning message in the multifunction display
(
page 368).
The engine should not be operated with a
coolant temperature above 248°F (120°C).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty.
iDuring severe operating conditions, e.g.
stop-and-go city traffic, the coolant temperature
may rise close to 248°F (120°C).

292 Operation
At the gas station
Close the fuel filler flap.
Check regularly and before a long trip
Engine compartment
(example illustration, SLK 350)
1Windshield washer system and head-
lamp cleaning system* reservoir
2Brake fluid reservoir
3Coolant expansion tankWindshield washer system and head-
lamp cleaning system*
For information on refilling the reservoir,
see “Windshield washer system and
headlamp cleaning system*”
(
page 302).
Brake fluid
For information on brake fluid, see “Fuels,
coolants, lubricants, etc.” (
page 443).
iMake sure to close the fuel filler flap before
locking your vehicle as the flap locking pin
prevents closing after you have locked the
vehicle.
iOnly use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average
of 96 RON/86 MON).
Information on gasoline quality can normally be
found on the fuel pump. Please contact gas
station personnel in case labels on the pump
cannot be found.
For more information on gasoline, see “Premium
unleaded gasoline” (
page 446), refer to the
Factory Approved Service Products pamphlet
(USA only), or contact an authorized
Mercedes-Benz-Center.
iLeaving the engine running and the fuel cap
open can cause the yellow fuel tank reserve
warning lamp to flash and the?malfunction
indicator lamp (USA only) or the
±malfunction indicator lamp (Canada only)
to illuminate.
For more information, see “Practical hints”
(
page 349).
iFor opening the hood, see “Hood”
(
page 294).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Center immediately.
Do not add brake fluid as this will not solve the
problem.
For more information, see “Practical hints”
(
page 348).


293 Operation
At the gas station
Coolant
For normal replenishing, use water
(potable water quality).
For more information on coolant, see
“Coolant level” (
page 300) and “Fuels,
coolants, lubricants, etc.” (
page 443).
Engine oil level
For information on engine oil, see “Engine
oil” (
page 296).Vehicle lighting
Check function and cleanliness.
For more information on vehicle lighting,
see “Replacing bulbs” (
page 393).
For information on switching on the exteri-
or lighting, see “Exterior lamp switch”
(
page 109).
Tire inflation pressure
For information on tire inflation pressure,
see “Important notes on tire inflation
pressure” (
page 313).

294 Operation
Engine compartment
Hood
Opening
1Hood lock release lever
Warning!G
Do not pull the release lever while the vehi-
cle is in motion. Otherwise the hood could
be forced open by passing air flow.
This could cause the hood to come loose
and injure you and/or others.
Warning!G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from the vehicle and do not open the
hood until the engine has cooled. If neces-
sary, call the fire department.
Warning!G
You could be injured when the hood is open
– even when the engine is turned off.
Parts of the engine can become very hot. To
prevent burns, let the engine cool of com-
pletely before touching any components on
the vehicle. Comply with all relevant safety
precautions.
Warning!G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades.
Warning!G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition coils, spark plug sockets, diagnostic
socket) of the ignition system

with the engine running

while starting the engine

if ignition is “on” and the engine is
turned manually

297 Operation
Engine compartment
One of the following messages will
subsequently appear in the multifunc-
tion display:

Engine oil level
OK

Add 1.0 qt. (Canada: 1.0 liter)
to reach max. oil level

Add 1.5 qts. (Canada:
1.5 liters)
to reach max. oil level

Add 2.0 qts. (Canada:
2.0 liters)
to reach max. oil level
If necessary, add engine oil.
For adding engine oil, see “Adding
engine oil” (
page 299).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 443).Other display messages
If the ignition is not switched on, the fol-
lowing message will appear:
Turn on ignition
to see engine oil level
Switch on the ignition (page 37).
If you see the message:
Observe waiting time
If engine is at operating temperature,
wait 5 minutes before repeating check
procedure.
If engine is not at operating tempera-
ture yet, you must wait 30 minutes
before checking oil.If you see the message:
Cannot check engine
level with engine on
Turn off the engine.
If the engine is at operating tempera-
ture, wait 5 minutes before checking
oil.
If the engine is not at operating
temperature yet, you must wait
30 minutes before checking oil.
iIf you want to interrupt the checking
procedure, press buttonk orj on the
multifunction steering wheel (
page 122).
iIf you want to interrupt the checking
procedure, press buttonk orj on the
multifunction steering wheel (
page 122).

299 Operation
Engine compartment
Pull out oil dipstick1 again after
approximately 3 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
engine oil” (
page 299).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 443).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 356).Adding engine oil
Only use approved engine oils and oil fil-
ters 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) in your vehicle litera-
ture portfolio, or contact an authorized
Mercedes-Benz Center.
Using engine oils and oil filters of
specification other than those expressly
required for the Maintenance System, or
changing of oil and oil filter at change inter-
vals 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.
SLK 350 (example illustration)
1Filler cap
SLK 55 AMG
1Filler cap
iThe filling quantity between the upper and
lower marks on the oil dipstick is approximately
2.1 US qt. (2.0 l).

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 443) and
(
page 445).
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. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!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.

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 448).

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 un-
der 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.

368 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop, turn engine
offThe 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)

369 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.