engine overheat MERCEDES-BENZ SLK-Class 2016 R172 Owner's Manual

Driving
Important safet ynotes
GWARNING
Objects in th edriver's footwell can restric tth e
peda ltrave lor obstruct adepressed pedal.
The operatin gand road safet yof th evehicle is
jeopardized. There is aris kof an accident.
Mak esur ethat all objects in th evehicle are
stowed correctly, and that they canno tente r
th edriver's footwell. Install th efloormat s
securely and as specifie din order to ensur e
sufficien tclearanc efo rth epedals. Do no tuse
loose floormat sand do no tplac efloormat son
to pof on eanother.
GWARNING
Unsuitable footwear can hinder correc tusag e
of th epedals, e.g. :
Rshoes withthic ksoles
Rshoes wit hhig hheels
Rslipper s
There is aris kof an accident.
Wear suitable footwear to ensur ecorrec t
usag eof th epedals.
GWARNING
If you switch of fth eignition whil edriving,
safety-relevant function sare only available
wit hlimitations, or no tat all. Thi scould affect,
fo rexample, th epowe rsteerin gand th ebrake
boostin geffect .You will require considerably
more effort to steer and brake .There is aris k
of an accident.
Do no tswitch of fth eignition whil edriving.
GWARNING
If th eparking brake has no tbee nfull y
release dwhen driving, th eparking brake can :
Roverheat and cause afir e
Rlos eits hol dfunction .
There is aris kof fir eand an accident. Release
th eparking brake full ybefor edrivin goff.
!Do no twarm up th eengin ewit hth evehi-
cl e stationary. Drive of fimmediately. Avoid
hig hengin espeeds and drivin gat full throt-
tl e until th eengin ehas reached it soperat -
in g temperature .
Only shift th eautomatic transmissio nto
th edesire ddrive position when th evehicle
is stationary.
Where possible, avoid spinnin gth edrive
wheels when pulling away on slipper y
roads. You could otherwise damage th e
drive train .
!Mercedes-AMG vehicles :at low engin e
oil temperature sbelo w68 ‡(+2 0†), th e
maximum engin espeed is restricte din
order to protect th eengine. To protect th e
engin eand maintain smoot hengin eoper-
ation ,avoid drivin gat full throttle when th e
engin eis cold.
SmartKe ypositions
SmartKe y
gTo removeth eSmartKey
Shift th etransmissio nto position P.
1Powersupply fo rsom econsumers ,suc h
as th ewindshield wipers
2Ignition (power supply fo rall consumers )
and drive position
3To start th eengin e
iThe SmartKey can be turned in th eigni-
tion loc keve nif it is no tth ecorrec tSmart -
Key fo rth evehicle. The ignition is no t
switched on .The engin ecanno tbe started.
Driving139
Driving and parking
Z

The ECO display does not indicate the actual
fuel consumption. A fixed percentage count
in the ECO display does not indicate a fixed
consumption.
Apart from driving style, consumption is
dependent on many factors such as, e.g.:
Rload
Rtire pressure
Rcold start
Rchoice of route
Relectrical consumers switched on
These factors are not included in the ECO dis-
play.
The evaluation of your driving style is carried
out using the following three categories:
RAccel.(evaluation of all acceleration pro-
cesses):
-The bar fills up: moderate acceleration,
especially at higher speeds
-The bar empties: sporty acceleration
RConstant(assessment of driving behavior
at all times):
-The bar fills up: constant speed and
avoidance of unnecessary acceleration
and deceleration
-The bar empties: fluctuations in speed
RCoasting(assessment of all deceleration
processes):
-The bar fills up: anticipatory driving,
keeping your distance and early release
of the accelerator. The vehicle can coast
without use of the brakes.
-The bar empties: frequent braking
iAn economical driving style specially
requires driving at moderate engine
speeds.
To achieve a higher value in the categories
Acceleration
and Constant:
Robserve the gearshift recommendations.
Rdrive in drive program E.
iOn long journeys at a constant speed, e.g.
on the highway, only the bar for Constant
will change.
iThe ECO display summarizes the driving
characteristics from the start of the journey
to its completion. For this reason, the bars change dynamically at the beginning of the
journey. On longer journeys, there are
fewer changes. For more dynamic changes,
carry out a manual reset.
For more information on the ECO display, see
(
Ypage 198).
Brakes
Important safety notes
GWARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients
!On long, steep gradients, you must
reduce the load on the brakes. To use
engine braking, shift to a lower gear in good
time. This helps you to avoid overheating
the brakes and wearing them out exces-
sively.
When making use of the engine braking
effect, it is possible that a drive wheel may
not turn for some time, e.g. in the case of
suddenly changing or slippery road surface
conditions. This could cause damage to the
drive train. This type of damage is not cov-
ered by the Mercedes-Benz warranty.
Change into a lower gear in good time on long
and steep downhill gradients. This is espe-
cially important if the vehicle is laden.
This also applies if you have activated cruise
control, SPEEDTRONIC or DISTRONIC PLUS.
Driving tips165
Driving and parking
Z

Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately, but
drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has been washed or driven through deep water.
You then have to depress the brake pedal
more firmly. Maintain a greater distance from
the vehicle in front.
After driving on a wet road or having the vehi- cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
RBrake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou hear a warning tone while the engine
is running
Observe additional warning messages in
the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. Consult a qualified specialist work-
shop to arrange this.
!As the ESP®system operates automati-
cally, the engine and the ignition must be
switched off (SmartKey in position 0or 1in
the ignition lock) if the electric parking
brake is being tested on a brake dynamom-
eter (maximum 10 seconds).
Braking triggered automatically by ESP
®
may seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the function-
ality of your brakes at regular intervals.
Information on BAS (Brake Assist)
(
Ypage 62).
Mercedes-Benz recommends that you only
have brake pads/linings installed on your
vehicle which have been approved for
Mercedes-Benz vehicles or which correspond
to an equivalent quality standard. Brake
166Driving tips
Driving and parking

GDANGER
If th eexhaust pipe is blocke dor adequate
ventilation is no tpossible, poisonous gase s
suc has carbon monoxide (CO) may ente rth e
vehicle. This is th ecase, e.g. if th evehicl e
become strapped in snow. There is aris kof
fatal injury.
If you leav eth eengin eor th eauxiliary heating
running, mak esur eth eexhaust pipe and area
around th evehicl eare clear of snow. To
ensur ean adequate supply of fresh air, open a
window on th eside of th evehicl ethat is no t
facing int oth ewind.
Hav eyour vehicl ewinter-proofe dat aquali-
fie dspecialist workshop at th eonset of win -
ter.
Drive particularly carefully on slipper yroad
surfaces. Avoid sudde nacceleration ,steering
and brakin gmaneuvers .Do no tuse cruise
control .
If th evehicl ethreaten sto skid or canno tbe
stoppe dwhen moving at low speed:
XShift th etransmission to position N.
The outside temperature indicator is no t
designed to serve as an ice-warnin gdevice
and is therefor eunsuitable for that purpose .
Changes in th eoutside temperature are dis-
played after ashort delay.
Indicate dtemperatures jus tabov eth efreez -
in g poin tdo no tguarantee that th eroad sur -
fac eis free of ice .The road may still be icy,
especially in w
ooded areas or on bridges
.The
vehicl ecould skid if you fail to adapt your
drivin gstyle. Always adapt your drivin gstyle
and drive at aspee dto suit th eprevailing
weather conditions.
You should pay special attention to road con-
dition swhen temperatures are around freez -
in g point.
Fo rmor einformation on drivin gwit hsnow
chains, see (
Ypage 311).
Fo rmor einformation on drivin gwit hsummer
tires ,see (
Ypage 310). Observ
eth enote sin th e"Winte roperation "
section (
Ypage 310).
Driving systems
Cruise Control
Genera l notes
Cruisecontrol maintains aconstan troad
spee dfor you. It brakes automatically in order
to avoi dexceedin gth eset speed. On lon gand
steep downhill gradients ,especially if th e
vehicl eis laden ,you mus tselect alower gear
in goo dtime. By doin gso, you will mak euse of
th ebrakin geffec tof th eengine. This relieves
th eload on th ebrak esystem and prevents
th ebrakes from overheating and wearing to o
quickly.
Use cruise control only if road and traffic con-
dition smak eit appropriat eto maintai n a
steady spee dfor aprolonged period. You can
store any road spee dabov e20 mph
(30 km/h).
Import ant safety notes
If you fail to adapt your drivin gstyle, cruise
control can neither reduce th eris kof an acci-
den tno roverride th elaws of physics .Cruis e
control canno ttak einto accoun tth eroad ,
traffic and weather conditions. Cruis econtrol
is only an aid. You are responsibl efor th edis-
tance to th evehicl ein front, for vehicl espeed,
for brakin gin goo dtime and for stayin gin
lane.
Do no tuse cruise control :
Rin road and traffic condition swhic hdo no t
allow you to maintai n aconstan tspee de.g.
in heav ytraffic or on windin groad s
Ron slipper yroad surfaces. Braking or accel-
eratin gcould caus eth edrive wheels to lose
traction and th evehicl ecould then skid
Rwhen there is poor visibility, e.g. due to fog ,
heav yrain or snow
If there is achang eof drivers, advise th ene w
driver of th espee dstored.
168Driving systems
Driving and parking

press the cruise control lever up:to the
pressure point for a higher speed or
down ?for a lower speed.
Every time the cruise control lever is
pressed up or down, the last speed stored
is increased or reduced.
XTo adjust the set speed in 5 mph incre-
ments (10 km/h increments): briefly
press the cruise control lever up :past
the pressure point for a higher speed or
down ?for a lower speed.
Every time the cruise control lever is
pressed up or down, the last speed stored
is increased or reduced.
iCruise control is not deactivated if you
depress the accelerator pedal. For exam-
ple, if you accelerate briefly to overtake,
cruise control adjusts the vehicle's speed
to the last speed stored after you have fin- ished overtaking.
Deactivating cruise control
Cruise control lever
There are several ways to deactivate cruise
control:
XBriefly press the cruise control lever for-
wards :.
or
XBrake.
Cruise control is automatically deactivated if:
Ryou engage the electric parking brake
Ryou are driving at less than 20 mph
(30 km/h)
RESP®intervenes or you deactivate ESP®
Ron vehicles with manual transmission, you
shift to a gear that is too high, and as a
result the engine speed is too low
Ryou shift the transmission to position N
while driving
If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise Con‐
trol Offmessage in the multifunction dis-
play for approximately five seconds.
iWhen you switch off the engine, the last
speed stored is cleared.
DISTRONIC PLUS
General notes
DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles are detected with the aid of the radar
sensor system. DISTRONIC PLUS brakes
automatically to avoid exceeding the set
speed or to maintain the designated distance
from the vehicle in front.
Change into a lower gear in good time on long
and steep downhill gradients. This is espe-
cially important if the vehicle is laden. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects that there is a risk
of a collision, you will be warned visually and
acoustically. DISTRONIC PLUS cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and the distance warning lamp will light up in the
instrument cluster. Brake immediately in
order to increase the distance to the vehicle
in front or take evasive action provided it is
safe to do so.
DISTRONIC PLUS operates in range between
0 mph (0 km/h) and 120 mph (200 km/ h).
Do not use DISTRONIC PLUS while driving on
roads with steep gradients.
170Driving system s
Driving an d parking

The segments between the speed of the
vehicle in front and the stored speed light
up.
Tachometer
!
Do not drive in the overrevving range, as
this could damage the engine.
The red band in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached.
Outside temperature display
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Bear in mind that the outside temperature
display indicates the temperature measured
and does not record the road temperature.
The outside temperature display is in the mul-
tifunction display (
Ypage 196).
A change in the outside temperature is shown
in the multifunction display after a delay.
Coolant temperature display
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
!A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over 248 ‡
(120 †), do not continue driving. The
engine will otherwise be damaged. The coolant temperature gauge is in the
instrument cluster on the right-hand side
(
Ypage 31).
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 248 ‡ (120 †).
Operating the on-board computer
Overview
:Multifunction display
;Switches on the Voice Control System
(see the separate operating instructions)
=Right control panel
?Left control panel
ABack button
XTo activate the on-board computer: turn
the SmartKey to position 1in the ignition
lock.
You can control the multifunction display and
the settings in the on-board computer using
the buttons on the multifunction steering
wheel.
Displays and operation195
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
?
CoolantToo Hot
Sto pVehicl eTur n
Engine Off
The coolan tis to ohot .
A warnin gtone also sounds.
GWARNIN G
Do notdrive when your engin eis overheated. This can caus esom e
fluids whic hmay hav eleaked into th eengin ecompartmen tto
catch fire.
Steam from th eoverheated engin ecan also caus eserious burn s
whic hcan occur jus tby openin gth ehood.
There is aris kof injury.
XPull ove rand stop th evehicl esafely and switch of fth eengine,
payin gattention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 160).
XLeaveth evehicl eand keep asaf edistanc efrom th evehicl euntil
th eengin ehas cooled down .
XMakesur ethat th eair supply to th eengin eradiato ris no t
blocked, e.g. by snow, slus hor ice .
XDo no tstart th eengin eagain until th edisplay message goe sout
and th ecoolan ttemperature is belo w24 8 ‡ (120†). Other -
wise ,th eengin ecould be damaged.
XPay attention to th ecoolan ttemperature display.
XIf th etemperature increase sagain ,visit aqualified specialist
workshop immediately.
Under normal operating condition sand wit hth especified coolan t
level, th ecoolan ttemperature may ris eto 24 8 ‡(120†).
#
SeeOperator' sMan‐
ual
The battery is no tbein gcharged.
A warnin gtone also sounds.
Possibl ecauses are:
Radefective alternato r
Ratorn poly-V-belt
Ramalfunction in th eelectronics
!Do no tcontinue driving. The engin ecould otherwise overheat .
XPull overand stop th evehicl esafely and switch of fth eengine,
payin gattention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 160).
XConsult aqualified specialist workshop .
228Display messages
On-board computer and displays

ProblemPossible causes/consequences andMSolutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may
be blocked or the electric engine radiator fan may be malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
XObserve the additional display messages in the multifunction
display.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 160).
XLeave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning
notes (
Ypage 279).
XIf you have to add coolant frequently, have the engine cooling
system checked.
XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XDo not start the engine again until the coolant temperature is
below 248‡(120 †). Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-and-go traffic.
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow to the engine radiator may be blocked or the coolant level may
be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction
display.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 160).
250Warning and indicator lamps
On-board computer and displays

Useful information
i
This Operator's Manual describes all
models and all standard and optional equip-
ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
iRead the information on qualified special-
ist workshops (
Ypage 25).
Engine compartment
Hood
Important safety notes
GWARNING
If the hood is unlatched, it may open up when the vehicle is in motion and block your view.
There is a risk of an accident.
Never unlatch the hood while driving. Before
every trip, ensure that the hood is locked.
GWARNING
When opening and closing the hood, it may
suddenly fall into the closed position. There is a risk of injury to persons within range of
movement of the hood.
Open and close the hood only when no one is
within its range of movement.
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
GWARNING
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There is a risk of injury.
If you need to do any work inside the engine
compartment:
Rswitch off the ignition
Rnever reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
Opening the hood
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
!Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
276Engine compartment
Maintenance and care

temperatures. The table shows you which
SAE classifications are to be used. The low-
temperature characteristics of engine oils
can deteriorate significantly, e.g. as a result
of aging, soot and fuel deposits. It is therefore
strongly recommended that you carry out reg-
ular oil changes using an approved engine oil
with the appropriate SAE classification.
Brake fluid
GWARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake
fluid is too low, vapor pockets may form in the
brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
When handling brake fluid, observe the
important safety notes on service products
(
Ypage 347).
The brake fluid change intervals can be found
in the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.co m.
iHave the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet.
Coolant
Important safety notes
GWARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
!Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications
for Service Products, MB BeVo 310.1, e.g.
on the Internet at
http://bevo.mercedes-benz.com. Or con-
tact a qualified specialist workshop.
!Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
iHave the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet.
Comply with the important safety precautions
for service products when handling coolant
(
Ypage 347).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
Rcorrosion protection
Rantifreeze protection
Rraising the boiling point
If the coolant has antifreeze protection down
to -35 ‡(-37 †), the boiling point of the cool-
350Service products and filling capacities
Technical data