2016 MERCEDES-BENZ SL ROADSTER engine

Engine compartment
Bonnet
Important safety notes G
WARNING
An unlocked bonnet may open up when the
vehicle is in motion and block your view. There is a risk of an accident.
Never unlock the bonnet when driving. Before
every trip, ensure that the bonnet is locked. G
WARNING
When being opened and closed, the bonnet
may suddenly fall into the closed position.
There is a risk of injury to persons in the range of movement of the bonnet.
Open and close the bonnet only when nobody
is in the range of movement. G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade. G
WARNING
There are moving components in the engine
compartment. Certain components may con-
tinue to move or suddenly move again even
after the ignition has been switched off, e.g.
the radiator fan. There is a risk of injury.
If you have to carry out work in the engine
compartment:
R switch off the ignition
R never touch the dangerous areas surround-
ing moving components, e.g. the rotation
area of the fan R
remove jewellery and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts.
Active bonnet (pedestrian protection) Operating principle
! An active bonnet that had been triggered
must be repaired at a qualified specialist
workshop. The active bonnet function will
then be available again. The additional pedes- trian protection provided by the active bonnet
will then be restored.
The active bonnet is only available in certain
countries.
The active bonnet can reduce the risk of injury to pedestrians in certain accident situations. Rais-
ing the active bonnet increases the clearance to hard components, such as the engine.
If the active bonnet has been triggered, it is
raised at the rear in the area around the hinge byapproximately 85 mm. The active bonnet is trig-
gered by pyrotechnics.
For the drive to the workshop, reset the trig-
gered active bonnet yourself. If the active bon-
net has been triggered, pedestrian protection
may be limited.
Resetting G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. 276
Engine compartmentMaintenance and care

X
With your hand flat, push down active bon-
net :in the area around the hinges on both
sides (arrows) until you feel it engage.
If you can raise the active bonnet slightly in the
area around the hinges, it is not engaged cor-
rectly. Repeat the step.
Opening the bonnet G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
When the bonnet is open, and the windscreen wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! Make sure that the windscreen wipers are
not folded away from the windscreen. Other-
wise, you could damage the windscreen wip-
ers or the bonnet. X
Make sure that the windscreen wipers are
switched off.
X Pull release lever :on the bonnet.
The bonnet is released. X
Reach into the gap, pull bonnet catch han-
dle ;up and lift the bonnet :.
If you lift the bonnet by approximately 40 cm, the bonnet is opened and held open automat-
ically by the gas-filled struts.
Closing the bonnet X
Lower the bonnet and let it fall from a height
of approximately 20 cm.
X Check that the bonnet has engaged properly.
If the bonnet can be raised slightly, it is not
properly engaged. Open it again and close it
with a little more force. Engine oil
Notes on oil level Depending on your driving style, the vehicle
consumes up to 0.8 litres of oil per 1,000 km.
The oil consumption may be higher than this Engine compartment
277Maintenance and care Z

when the vehicle is new or if you frequently drive
at high engine speeds.
Depending on the engine, the oil dipstick may be
installed at a different location.
When checking the oil level:
R park the vehicle on a level surface
R the engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature
R if the engine is not at normal operating tem-
perature, e.g. if the engine was only started
briefly, wait approximately 30 minutes before
carrying out the measurement
Checking the oil level using the oil dip-
stick G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. Example
X Pull oil dipstick :out of the oil dipstick tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick :into the guide tube
to the stop, and take it out again.
If the level is between MIN mark =and MAX
mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark =or
below, top up with 1.0 l of engine oil. Topping up engine oil G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil does not spill out
over the filler neck. Allow the engine to cool
down and thoroughly clean the components
that have come into contact with engine oil
before you start the engine. H
Environmental note
When topping up the 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 sys-
tem. You can obtain a list of the engine oils
and oil filters tested and approved in accord-
ance with the Mercedes-Benz Specifications
for Service Products at any Mercedes-Benz
Service Centre.
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 changing the engine oil and oil filter after
missing the change interval required by the
service system
R using engine oil additives
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic con-
verter. Have excess oil siphoned off. 278
Engine compartmentMaintenance and care

Example: engine oil filler cap
X Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 lof engine oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into
place.
X Check the oil level again with the oil dipstick
(Y page 278).
For further information on engine oil, see
(Y page 324). Checking and adding other service
products
Checking the coolant level G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury. Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure. Example
X Park the vehicle on a level surface.
Only check the coolant level if the vehicle is
on a level surface and the engine has cooled
down.
X Turn the key to position 2in the ignition lock
(Y page 132).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 132).
X Check the coolant temperature gauge in the
multifunction display.
The coolant temperature must be below
70 †.
X Turn the key to position 0(Y page 132) in the
ignition lock.
X Slowly turn cap ;half a turn anti-clockwise
to allow excess pressure to escape.
X Turn cap ;further anti-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank :.
If the coolant level is approximately 1.5 cm
above marker bar =in the filler neck when
warm, there is enough coolant in coolant
expansion tank :.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-Benz.
X Replace cap ;and turn it clockwise as far as
it will go.
Further information on coolant (Y page 325). Engine compartment
279Maintenance and care Z

Topping up the windscreen washer sys-
tem G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. Example
X To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages.
The recommended minimum washer fluid level
is 1 litre.
If the washer fluid level drops below 1 litre, a
message appears in the multifunction display
prompting you to top up the washer fluid
(Y page 242).
Further information on windscreen washer
fluid/antifreeze (Y page 326). Overview of the engine compartment
Example engine
:
Oil dipstick
; Brake fluid reservoir
= Engine oil cap
? Coolant expansion tank
A Washer fluid reservoir ASSYST PLUS
Service messages
The ASSYST PLUS service interval display
informs you of the next service due date.
Information on the type of service and service
intervals (see the separate Service Booklet).
You can obtain further information from a
Mercedes-Benz Service Centre. i The ASSYST PLUS service interval display
does not show any information on the engine oil level. Observe the notes on the engine oil
level (Y page 277).
The multifunction display shows a service mes-
sage for a few seconds, e.g.:
R Service A in .. days Service A in .. days
R Service A due
Service A due
R Service A overdue by .. days
Service A overdue by .. days
Depending on the operating conditions of the
vehicle, the remaining time or distance until the
next service due date is displayed.
The letter indicates which service is due. A A
stands for a minor service and B
Bfor a major ser-
vice. A number or another letter may be dis-
played after the letter.
Only for certain countries: the position after the
letter A
A or B Bindicates any necessary additional
maintenance work to be performed. If you notify 280
ASSYST PLUSMaintenance and care

a qualified specialist workshop of this display,
you will receive a statement on the associated
costs.
The ASSYST PLUS service interval display does
not take into account any periods of time during
which the battery is disconnected.
Maintaining the time-dependent service sched-
ule:
X Note down the service due date displayed in
the multifunction display before disconnect-
ing the battery.
or X After reconnecting the battery, subtract the
battery disconnection periods from the ser-
vice date shown on the display. Hiding service messages
X Press the aor% button on the steering
wheel. Displaying service messages
X Switch the ignition on.
X Press the =or; button on the steering
wheel to select the Serv. Serv.menu.
X Press the 9or: button to select the
ASSYST
ASSYST PLUS
PLUSsubmenu and confirm by press-
ing the abutton.
The service due date appears in the multi-
function display. Information about service
Resetting the ASSYST PLUS service
interval display !
If the ASSYST PLUS service interval display
has been inadvertently reset, this setting can
be corrected at a qualified specialist work-
shop.
Have service work carried out as described in the Service Booklet. This may otherwise lead
to increased wear and damage to the major
assemblies or the vehicle.
A qualified specialist workshop, e.g. a
Mercedes-Benz Service Centre, will reset the
ASSYST PLUS service interval display after the
service work has been carried out. You can also obtain further information on maintenance
work, for example.
Special service requirements The prescribed service interval is based on nor-
mal operation of the vehicle. Service work will
need to be performed more often if the vehicle is
operated under arduous conditions or increased loads, for example:
R regular city driving with frequent intermediate
stops
R if the vehicle is primarily used to travel short
distances
R for frequent operation in mountainous terrain
or on poor road surfaces
R if the engine is often left idling for long periods
In these or similar operating conditions, have,
for example, the air filter, engine oil and oil filter changed more frequently. The tyres must be
checked more frequently if the vehicle is oper-
ated under increased loads. Further informationcan be obtained at a qualified specialist work-
shop, e.g. a Mercedes-Benz Service Centre.
Driving abroad An extensive Mercedes-Benz Service network is
also available in other countries. You can obtain further information from any Mercedes-Benz
Service Centre. Care
Notes on care
H
Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
! For cleaning your vehicle, do not use any of
the following:
R dry, rough or hard cloths
R abrasive cleaning agents
R solvents
R cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective films
with hard objects, e.g. a ring or ice scraper. Care
281Maintenance and care Z

Flat tyre
Preparing the vehicle
Your vehicle may be equipped with: R tyres with run-flat characteristics
(MOExtended tyres) (Y page 289)
Vehicle preparation is not necessary on vehi- cles with MOExtended tyres.
R a TIREFIT kit (Y page 288)
R an emergency spare wheel (certain countries
only) (Y page 318)
Vehicles with MOExtended tyres are not equip-
ped with a TIREFIT kit at the factory. It is there-
fore recommended that you additionally equip
your vehicle with a TIREFIT kit if you fit tyres that do not feature run-flat characteristics, e.g. win-
ter tyres. A TIREFIT kit can be obtained from a
qualified specialist workshop.
Information on changing and fitting a wheel
(Y page 312).
X Stop the vehicle as far away as possible from
traffic on solid, non-slippery and level ground.
X Switch on the hazard warning lamps.
X Safeguard the vehicle against rolling away
(Y page 153).
X If possible, bring the front wheels into the
straight-ahead position.
X Switch off the engine.
X Vehicles without KEYLESS-GO: remove the
key from the ignition lock.
X Vehicles with KEYLESS-GO: open the driv-
er's door.
The on-board electronics now have status 0.
This is the same as the key having been
removed.
X Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
(Y page 132).
X Make sure that the passengers are not endan-
gered as they do so. Make sure that no one is
near the danger area while a wheel is being
changed. Anyone who is not directly assisting in the wheel change should, for example,
stand behind the barrier.
X Get out of the vehicle. Pay attention to traffic
conditions when doing so.
X Close the driver's door.
X Place the warning triangle at a suitable dis-
tance (Y page 287). Observe legal require-
ments. MOExtended tyres (tyres with run-flat
characteristics)
General notes With MOExtended tyres (tyres with run-flat char-
acteristics), you can continue to drive your vehi- cle even if there is a total loss of pressure in one
or more tyres. The affected tyre must not show
any clearly visible damage.
You can recognise MOExtended tyres by the
MOExtended marking which appears on the tyre wall. You will find this marking next to the tyre
size designation, the load-bearing capacity and
the speed index.
MOExtended tyres may only be used in conjunc-tion with an activated tyre pressure loss warning
system or tyre pressure monitor.
If a pressure loss warning message appears in the multifunction display:
R observe the instructions in the display mes-
sages (Y page 237)
R check the tyre for damage
R if driving on, observe the following notes
The driving distance possible in run-flat mode is
approximately 80 km when the vehicle is parti-
ally laden and approximately 30 km when the
vehicle is fully laden.
In addition to the vehicle load, the driving dis-
tance possible depends upon:
R vehicle speed
R road condition
R outside temperature
The driving distance possible in run-flat mode
may be reduced by extreme driving conditions/
manoeuvres, or it can be increased through a
moderate style of driving.
The driving distance possible in run-flat mode is counted from the moment the tyre pressure loss
warning appears in the multifunction display.
You must not exceed a maximum speed of
80 km/h.
When replacing one or all tyres, observe the fol-
lowing specifications for your vehicle's tyres:
R size
R type and
R the "MOExtended" mark
If a tyre has gone flat and cannot be replaced
with an MOExtended tyre, a standard tyre may
be used as a temporary measure. Make sure Flat tyre
289Breakdown assistance Z

X
To reduce the tyre pressure: depress pres-
sure release button Enext to pressure gauge
F.
X When the tyre pressure is correct, unscrew
the filler hose from the valve of the sealed
tyre.
X Screw the valve cap onto the tyre valve of the
sealed tyre.
X Pull the tyre sealant bottle out of the tyre
inflation compressor.
The filler hose stays on the tyre sealant bottle.
X Drive to the nearest qualified specialist work-
shop and have the tyre changed there.
X Have the tyre sealant bottle replaced as soon
as possible at a qualified specialist workshop.
X Have the tyre sealant bottle replaced every
four years at a qualified specialist workshop. Battery (vehicle)
Important safety notes
Work on the battery, e.g. removing or fitting,
requires specialist knowledge and the use of
special tools. Therefore, always have work on
the battery carried out at a qualified specialist
workshop. G
WARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This can lead to function restrictions applying to
safety-relevant systems, e.g the lighting sys-
tem, the ABS (anti-lock braking system) or the
ESP ®
(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example:
R when braking
R in the event of abrupt steering manoeuvres
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci- dent, contact a qualified specialist workshop
immediately. Do not drive any further. Always have work on the battery carried out at a
qualified specialist workshop.
Further information about ABS (Y page 62) and
ESP ®
(Y page 67). G
WARNING
Electrostatic build-up can lead to the creation of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle body to remove any existing electrostatic
build-up.
The highly flammable gas mixture is created
while the battery is charging and when jump-
starting.
Always make sure that neither you nor the bat-
tery is electrostatically charged. Electrostatic
charge is created, for example: R by wearing synthetic fibre clothing
R by friction between clothing and the seat
R when you pull or push the battery across car-
pet or other synthetic materials
R when you rub the battery with a cloth G
WARNING
During the charging process, a battery produ- ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jump leads.
R Never connect or disconnect the battery
terminals while the engine is running. Battery (vehicle)
293Breakdown assis tance Z