engine overheat MERCEDES-BENZ METRIS 2018 MY18 Operator’s Manual

Useful information
This Operator's Manual describes all models as
well as standard and optional equipment of your
vehicle that were available at the time of going
to print. Country-specific variations are possi-
ble. Note that your vehicle may not be equipped
with all of the described functions. This also
applies to systems and functions relevant to
safety.
Read the information on qualified specialist
workshops (
Ypage 31).
Breaking-in notes
Important safety notes
In certain driving and driving safety systems, the
sensors adjust automatically while a certain dis-
tance is being driven after the vehicle has been
delivered or after repairs. Full system effective- ness is not reached until the end of this teach-in
procedure.
New or replaced brake pads and brake discs
only reach their optimal braking effect after a
few hundred kilometers of driving. Until then,
compensate for this by applying greater force to
the brake pedal.
The first 1000 miles (1500 km)
For the service life and economy of your vehicle
it is crucial that you break in the engine with due
care.
RTherefore, protect the engine for the first
1000 miles (1500 km) by driving at varying
vehicle and engine speeds.
RAvoid overstraining the vehicle and high
engine speeds during this period, e.g. driving
at full throttle. Do not exceed Øof the per-
missible maximum speed for each gear.
RDo not change down a gear manually in order to brake.
RTry to avoid depressing the accelerator pedal
beyond the pressure point (kickdown).
After 1000 miles (1500 km), you can increase
the engine speed gradually and accelerate the
vehicle to full speed.
iYou should also observe these notes on
breaking-in if the engine or parts of the drive
train on your vehicle have been replaced.
Driving
Important safety notes
GWARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
GWARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
Roverheat and cause a fire
Rlose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
!Warm up the engine quickly. Do not use the
engine's full performance until it has reached
operating temperature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
122Driving
Driving and parking

Mercedes-Benz recommends that you have the
maximum permissible speed programed at a
Mercedes-Benz Commercial Van Center.
Before overtaking, take into consideration that
the engine speed limiter prevents the speed
increasing beyond the programmed permissible
maximum speed.
Driving abroad
Service
An extensive network of authorized Mercedes-
Benz Centers is also at your disposal when you
are traveling abroad. Nevertheless, please bear
in mind that service facilities or replacement
parts may not always be immediately available.
The relevant workshop directories are available
from any Mercedes-Benz Commercial Van Cen-
ter.
Fuel
In some countries, only fuels with a higher sulfur
content are available.
Unsuitable fuel can cause engine damage. You
will find information about fuel under "Service
products and capacities" (
Ypage 307).
Low-beam headlamps
General notes
When driving in countries in which traffic drives
on the opposite side of the road to the country
where the vehicle is registered, you must switch
the headlamps to symmetrical low beam. This
prevents oncoming traffic from being blinded.
Symmetrical low beam does not illuminate as
large an area of the edge of the road.
Vehicles with halogen headlamps
The headlamps do not need to be switched to
symmetrical low beam. The legal requirements
of countries in which traffic drives on the oppo-
site side of the road to the country where the
vehicle is registered are met without the need to
convert the headlamps.
Transport by rail
Transporting your vehicle by rail may be subject
to certain restrictions or require special meas- ures to be taken in some countries due to vary-
ing tunnel heights and loading standards.
You can obtain information on this from any
Mercedes-Benz Commercial Van Center.
Braking
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
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
This also applies to automatic braking if you
have activated cruise control.
On long and steep downhill gradients, you
should change down to shift range 2or1 in
good time (
Ypage 130).
This should be observed in particular when driv-
ing with a laden vehicle and when towing a
trailer.
You thereby make use of the braking effect of
the engine and do not have to brake as often to
maintain the speed. This relieves the load on the
service brake and prevents the brakes from
overheating and wearing too quickly.
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.
Driving tips139
Driving and parking
Z

Rthe maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
Rthe maximum permissible gross weight of
vehicle/trailer combination
The applicable permissible values that may not
be exceeded can be found:
Rin your vehicle documents
Ron the type plates for the trailer tow hitch
Ron the type plates for the trailer
Ron the vehicle identification plate
(Ypage 305)
Where the values differ, the lowest is valid.
You will find the values approved by the manu-
facturer on the vehicle identification plates and
those for the towing vehicle in the "Technical
data" section (
Ypage 316).
Your vehicle behaves differently with a trailer
than without one.
The vehicle/trailer combination:
Ris heavier
Ris restricted in its acceleration and gradient-
climbing capability
Rhas an increased braking distance
Ris more susceptible to strong crosswinds
Rrequires more sensitive steering
Rhas a larger turning circle
This may impair the handling characteristics.
When towing a trailer, always adjust your speed
to suit the road and weather conditions. Drive
carefully. Maintain a safe dista nce.
If y

ou require any further explanation regarding
the information contained in the Operating
Instructions, please contact a Mercedes-Benz
Commercial Van Center.
General notes
RObserve the legally permitted maximum
speed for vehicle/trailer combinations in the
relevant country, state or Canadian province.
Before beginning the journey, check the trail-
er's documents for the maximum permitted
speed of your trailer.
This reduces the risk of accidents.
RInstall only an approved trailer coupling on
your vehicle. Only use a ball coupling for your Metris trailer tow hitch if it has been approved
for your vehicle. More information on the
availability, mounting and installation of the trailer electrics is available at any qualified
specialist workshop.
RThe trailer coupling is one of the most impor-
tant vehicle parts with regard to road safety.
Observe the notes on operation, care and
maintenance of the trailer tow hitch (see the
manufacturer's operating instructions).
RThe bumpers of your vehicle are not suitable
for installing detachable trailer couplings.
RDo not attach rented trailer tow hitches or
other detachable trailer tow hitches to the
bumper.
RMinimize the risk of damage to the ball cou-
pling. If you do not require the ball coupling,
remove it from the ball coupling recess.
Yo u w
ill find weight information under "Techni-
cal data" (Ypage 316).
The height of the ball neck changes according to
the load on the vehicle. If this is case, use a
trailer with a height-adjustable trailer drawbar.
Driving tips
The maximum permissible speed for vehicle/
trailer combination depends on the type of
trailer. Before beginning the journey, check the
trailer's documents for the maximum permitted
speed of your trailer. Observe the legally per-
mitted maximum speed in the relevant country, state or Canadian province.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison to
when driving without a trailer and it will con-
sume more fuel.
On long and steep downhill gradients, select a
lower gear.
iThis also applies if cruise control is activa-
ted.
This enables you to utilize the engine's braking
effect and you do not need to brake so heavily to keep the correct speed. This relieves the load on
the brake system and prevents the brakes from overheating and wearing too quickly. If you need
to brake additionally, to not depress the brake
pedal constantly, but periodically.
Observe the notes on ESP
®trailer stabilization
(Ypage 67).
166Towing a trailer
Driving an d parking

This enables you to gain experience and get
used to the new handling characteristics.
RBefore driving, check:
-that the trailer tow hitch and ball coupling
are secure
-that the safety switch for a braked trailer is
functioning properly
-that the safety chains are secure and not
damaged
-that the electrical connections are secure
-that the lights are working
-that the wheels are in good order and the
tire pressure is correct
RAdjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
RIf the trailer is equipped with a separate func-
tional braking system, check before each
journey whether the brakes are functioning
correctly.
RSecure the load on the trailer according to the
applicable specifications and current stand-
ards on securing loads (
Ypage 246).
RWhen driving with a trailer, check at regular
intervals that the load is secured and that the
brakes and lights are working.
RBear in mind that the handling will be less
stable when towing a trailer than when driving
without one. Avoid sudden steering move-
ments.
RThe vehicle/trailer combination is heavier,
accelerates more slowly and has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to crosswinds and
requires cautious steering.
RIf possible, do not brake suddenly, but rather
moderately at first so that the trailer can acti-
vate its brakes. Then increase the force on the
brake pedal.
RIf the automatic transmission repeatedly
shifts between gears when driving on inclines,
restrict the shift range. Select shift range 4,3,
2 or 1.
Driving in a low gear and at a low speed
reduces the risk of damaging the engine.
RWhen driving on a downhill gradient, shift to a
low gear and take advantage of the engine's
braking effect. Avoid continuous brake application as this
may overheat the vehicle brakes and, if instal-
led, the trailer brakes.
RIf the coolant temperature increases dramat-
ically while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by
switching the airflow and the temperature of
the air conditioning to the
maximum level.
Open t

he windows if necessary.
RWhen overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of your vehicle/trailer com-
bination you need an additional distance
before you can return to your original lane.
Uncoupling a trailer
GWARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
!Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun
brake.
XMake sure that the selector lever of the auto-
matic transmission is in position P.
XEngage the vehicle's parking brake.
XClose all doors.
XApply the parking brake of the trailer.
XIn addition, secure the trailer against rolling
away with a wheel chock or similar object.
XRemove the trailer cable and safety chains
and decouple the trailer.
168Towing a trailer
Driving and parking

On vehicles with steering wheel buttons, the
light sensor in the instrument cluster automati-
cally controls the brightness of the display light-
ing.
While the lights are on, the brightness is depend-
ent upon the brightness of the ambient light.
You can also adjust the brightness of the instru-
ment lighting and the display lighting
Rby pressing thefand gbuttons on the
instrument cluster on vehicles without steer-
ing wheel buttons (not in the Settings
menu)
Rby turning brightness control knob :on vehi-
cles with steering wheel buttons
Speedometer
If you change the wheel size on your vehicle,
make sure it is assigned to the correct wheel
size category (
Ypage 279). If you change wheel
size category without recoding the control unit,
the speedometer indication will be inaccurate.
The current vehicle speed may then be higher
than the speed displayed in the speedometer.
The speed can also be shown in the display in
the form of a digital speedometer:
ROn vehicles without steering wheel buttons
(Ypage 175)
ROn vehicles with steering wheel buttons
(Ypage 181)
iIn some countries, a warning sounds and/or
the display shows a message when the vehi-
cle reaches the maximum legally permissible speed limit, e.g. at 75 mph (120 km/h).
Tachometer
!
Do not drive in the overrevving range, as this
could damage the engine.
HEnvironmental note
Avoid driving at high engine speeds. This
unnecessarily increases the fuel consumption
of your vehicle and harms the environment as
a result of increased emissions.
The red band in the tachometer indicates the
engine's overrevving range.
To protect the engine, the fuel supply is inter-
rupted when the red band is reached.
Outside temperature display
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Please bear in mind that the outside tempera-
ture display shows the air temperature meas-
ured and not the road temperature.
The display shows the outside temperature in
the header:
Ron vehicles without steering wheel buttons
(Ypage 173)
Ron vehicles with steering wheel buttons
(Ypage 179)
Changes in the outside temperature are dis-
played after a short delay.
Coolant temperature gauge
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.
On vehicles without steering wheel buttons, you
can have the coolant temperature shown in the
display (
Ypage 175).
On vehicles with steering wheel buttons, an ana-
log coolant temperature gage is located in the
tachometer in the instrument cluster
(
Ypage 39).
Under normal operating conditions and with the
specified coolant level, the gauge may rise to
248 ‡ (120 †).
172Display and operation
On-board computer and displays

Use the buttons in the instrument cluster.
XTo display:pressÈto select the trip com-
puter display.
The values displayed relate to those meas-
ured since the trip computer was last reset.
XTo reset values: press and hold3until all
values are reset.
The trip computer is automatically reset if the
value exceeds 9,999 hours or 99,999 miles.
You can set the unit of measurement for con-
sumption and distance in the Distance Unit:
submenu (Ypage 177).
Range menu
Use the buttons in the instrument cluster.
XPressÈto select the Rangedisplay.
The approximate range that can be covered is calculated according to your current driving
style and the amount of fuel in the tank. If
there is only a small amount of fuel left in the
fuel tank, the display shows a vehicle being
refueled Ïinstead of the approximate
range.
You can set the unit of measurement for dis-
tance in the Distance Unit:
submenu
(Ypage 177).
Current fuel consumption menu
:Recuperation display
;Range Use the buttons in the instrument cluster.
XPress
Èto select the fuel consumption bar
display.
Recuperation display :shows whether, and, if
so, how much kinetic energy is being trans-
formed into electric current whilst the vehicle is
coasting. The recuperated energy is then stored in the starter battery. Recuperation display :is
dependent on the engine installed and is there-
fore not available in all vehicles.
You can set the unit of measurement for con-
sumption in the Distance Unit:
submenu
(Ypage 177).
Digital speedometer menu
Use the buttons in the instrument cluster.
XPress Èto select the speed display.
You can set the unit for the digital speedometer
in the Distance
Unit:submenu (Ypage 177).
Coolant temperature menu
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.
Use the buttons in the instrument cluster.
XPress Èto select the ?coolant temper-
ature bar display.
Under normal operating conditions and with the
specified coolant level, the gauge may rise to
248 ‡ (120 †).
On-board computer (vehicles without steering wheel buttons)175
On-board computer and displays
Z

Engine
Display messagesPossible causes/consequences andMSolutions
#An additional warning tone sounds. The battery is not being charged.
Possible causes:
Rfaulty alternator
Rtorn poly-V-belt
Ra malfunction in the electronics
XStop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
!Do not continue driving. The engine could otherwise overheat.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
XConsult a qualified specialist workshop.
?
Stop Vehicle TurnEng. Off
An additional warning tone sounds. The coolant is too hot.
GWARNING
Never drive with an overheated engine. Driving when the engine is
overheated can cause fluids which may have leaked into the engine
compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the hood.
There is a risk of injury.
XStop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
XWait until the engine has cooled down.
XMake sure that the air supply to the radiator is not obstructed, by
frozen slush for example.
XDo not start the engine again until the display message goes out and
the coolant temperature is below the maximum value specified. The
engine could otherwise be damaged.
XPay attention to the coolant temperature gauge (Ypage 175).
XIf the temperature increases again, visit a qualified specialist work-
shop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature gauge may rise to 248 ‡ (120 †).
?The fan motor is faulty.
XCheck the coolant temperature (Ypage 175).
XIf the coolant temperature is below the maximum value specified
below, you can continue driving to the nearest qualified specialist
workshop.
Avoid heavy loads on the engine, e.g. driving in mountainous terrain,
and stop-and-go traffic.
Under normal operating conditions and with the specified coolant
level, the coolant temperature gauge may rise to 248 ‡ (120 †).
200Display messages (vehicles without steering wheel buttons)
On-board computer and displays

Engine
Display messagesPossible causes/consequences andMSolutions
#An additional warning tone sounds. The battery is not being charged.
Possible causes:
Rfaulty alternator
Rtorn poly-V-belt
Ra malfunction in the electronics
XStop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
!Do not continue driving. The engine could otherwise overheat.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
XConsult a qualified specialist workshop.
?
Coolant Too Hot:Stop Vehicle TurnEngine Off
An additional warning tone sounds. The coolant is too hot.
GWARNING
Never drive with an overheated engine. Driving when the engine is
overheated can cause fluids which may have leaked into the engine
compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the hood.
There is a risk of injury.
XStop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
XWait until the engine has cooled down.
XMake sure that the air supply to the radiator is not obstructed, by
frozen slush for example.
XDo not start the engine again until the display message goes out and
the coolant temperature is below the maximum value specified. The
engine could otherwise be damaged.
XMonitor the ?coolant temperature gauge in the instrument
cluster.
XIf the temperature increases again, visit a qualified specialist work-
shop immediately.
Under normal operating conditions and with the specified coolant
level, the ?gauge may rise to 248 ‡ (120 †).
214Display messages (vehicles with steering wheel buttons)
On-board computer and displays

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
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 malfunctioning.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the display messages.
XStop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
XExit 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 255).
XIf you have to add coolant more frequently, have the engine cooling system
checked.
XMake sure that the air supply to the radiator is not obstructed, by frozen slush
for example.
XCheck the coolant temperature:
Rusing the display in the on-board computer on vehicles without steering wheel
buttons (Ypage 175)
Rusing the analog display in the instrument cluster on vehicles with steering
wheel buttons (Ypage 39)
XDo not start the engine again until the coolant temperature is below the maxi-
mum value specified below. The engine could otherwise be damaged.
XDrive to the nearest qualified specialist workshop.
Avoid heavy loads on the engine, e.g. driving in mountainous terrain, and stop-
start traffic.
Under normal operating conditions and with the specified coolant level, the cool-
ant temperature gage may rise to 248 ‡ (120 †).
?N The red coolant warning lamp comes on while the engine is running. An addi-
tional warning tone sounds.
The coolant temperature has exceeded the maximum value specified below. The
airflow to the engine radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled adequately and could become damaged.
Never drive with an overheated engine. Otherwise, fluids which may have leaked
into the engine compartment could catch fire.
In addition, steam from an overheated engine can cause serious burns, which can
occur just by opening the hood.
There is a risk of injury.
XObserve the display messages.
XStop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
228Indicator and warning lamps in the instrument cluster
On-board computer and displays

Useful information
This Operator's Manual describes all models as
well as standard and optional equipment of your
vehicle that were available at the time of going
to print. Country-specific variations are possi-
ble. Note that your vehicle may not be equipped
with all of the described functions. This also
applies to systems and functions relevant to
safety.
Read the information on qualified specialist
workshops (
Ypage 31).
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
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
GWARNING
The ignition system operates with a high volt- age. If you touch the live components, you
could receive an electric shock. There is an
increased risk of injury.
Never touch components of the ignition sys-
tem if:
Rthe engine is running or being started
Rthe key is in radio position or drive position
in the ignition lock
The live components of the ignition system are,
for example:
Rignition coils
Rspark plug connectors
Rdiagnostic sockets
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.
If you have to carry out work in the engine com-
partment, only touch the following components:
Rhood
Roil dipstick
Rengine oil filler neck cap
Rwasher fluid reservoir cap
Rcoolant expansion tank cap
252Engine compartment
Maintenance and care