2020 MERCEDES-BENZ METRIS engine overheat

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
possible. Note that your vehicle may not be
equipped with all of the described functions.
This also applies to systems and functions rel-
evant to safety.
Read the information on qualified specialist
workshops (Y page
32).Breaking-in notes
Important safety notes
In certain driving and driving safety systems,
the sensors adjust automatically while a cer-
tain distance is being driven after the vehicle
has been delivered or after repairs. Full system
effectiveness 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 vehi-
cle it is crucial that you break in the engine
with due care.
R Therefore, protect the engine for the first
1000 miles (1500 km

) by driving at varying
vehicle and engine speeds.
R Avoid overstraining the vehicle and high
engine speeds during this period, e.g. driv-
ing at full throttle. Do not exceed Ø of the
permissible maximum speed for each gear.
R Do not change down a gear manually in
order to brake.
R Try 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.
i You 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
G
WARNING
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. G
WARNING
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. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake
can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident.
Release the parking brake fully before driv-
ing 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
stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train. 126
Driving
Driving and parking

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
opposite 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 sub-
ject to certain restrictions or require special
measures to be taken in some countries due
to varying tunnel heights and loading stand-
ards.
You can obtain information on this from any
Mercedes-Benz Commercial Van Center. Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface
in an attempt to increase the engine's brak-
ing effect, the drive wheels could lose their
grip. There is an increased danger of skid-
ding 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 2 or 1 in
good time
(Y page 133).
This should be observed in particular when
driving 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 G
WARNING
If you rest your foot on the brake pedal
while driving, the braking system can over-
heat. 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.
Drive on for a short while. The brakes are
cooled down more quickly in the airflow.
Wet road surfaces If you have been driving for a long time in
heavy rain without braking, there may be a
delayed response when you first apply the
brakes. This may also occur after driving
through a car wash or deep water.
You must depress the brake pedal more firmly.
Maintain a longer distance to the vehicle in
front.
While paying attention to the traffic conditions,
you should brake the vehicle firmly after driv-
ing on a wet road surface or through a car
wash. This heats the brake discs, so that they
dry more quickly, which protects them against
corrosion.
Limited braking performance on salt-
treated roads When driving on salted roads, salt may start to
build up on the brake disks and brake pads.
This can increase braking distances considera-
bly.
Maintain a greater distance to the vehicle in
front.
To remove any build-up of salt that may have
formed:
X Apply the brakes at the start of the journey,
occasionally during journey and at the end 142
Driving tips
Driving and parking

Ensure that the following weights are not
exceeded:
R the permissible noseweight
R the permissible trailer load
R the permissible rear axle load of the towing
vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
R the maximum permissible gross weight of
vehicle/trailer combination
The applicable permissible values that may not
be exceeded can be found:
R in your vehicle documents
R on the type plates for the trailer tow hitch
R on the type plates for the trailer
R on the vehicle identification plate
(Y page
304)
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 "Tech-
nical data" section (Y page 315).
Your vehicle behaves differently with a trailer
than without one.
The vehicle/trailer combination:
R is heavier
R is restricted in its acceleration and gradient-
climbing capability
R has an increased braking distance
R is more susceptible to strong crosswinds
R requires more sensitive steering
R has a larger turning radius
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 distance.
If you require any further explanation regard-
ing the information contained in the Operating
Instructions, please contact a Mercedes-Benz
Commercial Van Center.
General notes R
Observe the legally permitted maximum
speed for vehicle/trailer combinations in
the relevant country, state or Canadian
province. Before beginning the journey,
check the trailer's documents for the maxi-
mum permitted speed of your trailer. This reduces the risk of accidents.
R Install 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.
R The trailer coupling is one of the most
important 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 instruc-
tions).
R The bumpers of your vehicle are not suitable
for installing detachable trailer couplings.
R Do not attach rented trailer tow hitches or
other detachable trailer tow hitches to the
bumper.
R Minimize the risk of damage to the ball cou-
pling. If you do not require the ball coupling,
remove it from the ball coupling recess.
You will find weight information under "Techni-
cal data"
(Y page 315).
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 per-
mitted speed of your trailer. Observe the
legally permitted maximum speed in the rele-
vant 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.
i This 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 Towing a trailer
169
Driving and parking Z

Observe the following when towing a trailer:
R Practice driving around bends, stopping and
backing up at a place where there is no traf-
fic. This enables you to gain experience and
get used to the new handling characteris-
tics.
R Before 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
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer is equipped with a separate
functional braking system, check before
each journey whether the brakes are func-
tioning correctly.
R Secure the load on the trailer according to
the applicable specifications and current
standards on securing loads
(Y page 244).
R When driving with a trailer, check at regular
intervals that the load is secured and that
the brakes and lights are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
R The 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.
R If possible, do not brake suddenly, but
rather moderately at first so that the trailer
can activate its brakes. Then increase the
force on the brake pedal.
R If 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. R
When 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
installed, the trailer brakes.
R If the coolant temperature increases dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can also be dissipated by
switching the airflow and the temperature of
the air conditioning to the maximum level.
Open the windows if necessary.
R When overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of your vehicle/trailer
combination you need an additional dis-
tance before you can return to your original
lane. Uncoupling a trailer
G
WARNING
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 rebound-
ing of the overrun brake.
X Make sure that the selector lever of the
automatic transmission is in position P.
X Engage the vehicle's parking brake.
X Close all doors.
X Apply the parking brake of the trailer.
X In addition, secure the trailer against rolling
away with a wheel chock or similar object.
X Remove the trailer cable and safety chains
and decouple the trailer. Towing a trailer
171
Driving and parking Z

In daylight, the displays in the instrument clus-
ter are illuminated. A dimming function is not
possible in daylight.
On vehicles with steering wheel buttons, the
light sensor in the instrument cluster automat-
ically controls the brightness of the display
lighting.
While the lights are on, the brightness is
dependent upon the brightness of the ambient
light. You can also adjust the brightness of the
instrument lighting and the display lighting:
R by pressing the f and g buttons on the
instrument cluster on vehicles without
steering wheel buttons (not in the Settings
menu)
R by turning brightness control knob : on
vehicles 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 ( Y page
278). If you change
wheel size category without recoding the con-
trol 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:
R on vehicles without steering wheel buttons
(Y page 178)
R on vehicles with steering wheel buttons
(Y page 185)
i In some countries, a warning sounds
and/or the display shows a message when
the vehicle 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. H
Environmental note
Avoid driving at high engine speeds. This
unnecessarily increases the fuel consump-
tion of your vehicle and harms the environ-
ment 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 con-
ditions 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:
R on vehicles without steering wheel buttons
(Y page

176)
R on vehicles with steering wheel buttons
(Y page 183)
Changes in the outside temperature are dis-
played after a short delay. Coolant temperature gauge
G
WARNING
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

(Y page 178).
On vehicles with steering wheel buttons, an
analog coolant temperature gauge is located
in the tachometer in the instrument cluster
(Y page 40). Under normal driving conditions and at the
correct coolant level, the display may rise to
the letter H or to the red mark. Display and operation
175
On-board computer and displays Z

Use the buttons in the instrument cluster.
X To display: press È to select the trip com-
puter display.
The values displayed relate to those meas-
ured since the trip computer was last reset.
X To reset values: press and hold 3 until 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 ( Y page 180).Range menu
Use the buttons in the instrument cluster.
X Press È to select the Range display.
The approximate range that can be covered
is calculated according to your current driv-
ing 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 Ï instead of the approxi-
mate range.
You can set the unit of measurement for dis-
tance in the Distance Unit: submenu
(Y page

180). Current fuel consumption menu
:
Recuperation display
; Range Use the buttons in the instrument cluster.
X Press È to 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 dis-
play : is dependent on the engine installed
and is therefore not available in all vehicles.
You can set the unit of measurement for con-
sumption in the Distance Unit: submenu
(Y page

180). Digital speedometer menu
Use the buttons in the instrument cluster.
X Press È to select the speed display.
You can set the unit for the digital speedome-
ter in the Distance Unit: submenu
(Y page

180). Coolant temperature menu
G
WARNING
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. 178
On-board computer (vehicles without steering wheel buttons)
On-board computer and displays

Engine
Display messages
Possible causes/consequences and
M Solutions# An additional warning tone sounds. The battery is not being
charged.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
! Do not drive any further. Otherwise the engine may overheat.
X Secure the vehicle to prevent it from rolling away ( Y page 138).
X Consult a qualified specialist workshop. ?
Stop Vehicle Turn
Eng. Off An additional warning tone sounds. The coolant is too hot.
G WARNING
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.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away ( Y page
138).
X Wait until the engine has cooled down.
X Make sure that the air supply to the radiator is not obstructed, by
frozen slush for example.
X Do not start the engine again until the display message goes out
and the coolant temperature is below the maximum value speci-
fied. The engine could otherwise be damaged.
X Pay attention to the coolant temperature gauge (Y page
178).
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal driving conditions and at the correct coolant level, the
coolant temperature gauge may rise to the letter H.204
Display messages (vehicles without steering wheel buttons)
On-board computer and displays

Engine
Display messages
Possible causes/consequences and
M Solutions# An additional warning tone sounds. The battery is not being
charged.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
! Do not drive any further. Otherwise the engine may overheat.
X Secure the vehicle to prevent it from rolling away ( Y page 138).
X Consult a qualified specialist workshop. ?
Coolant Too Hot:
Stop Vehicle Turn
Engine Off An additional warning tone sounds. The coolant is too hot.
G WARNING
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.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away ( Y page
138).
X Wait until the engine has cooled down.
X Make sure that the air supply to the radiator is not obstructed, by
frozen slush for example.
X Do not start the engine again until the display message goes out
and the coolant temperature is below the maximum value speci-
fied. The engine could otherwise be damaged.
X Monitor the ? coolant temperature gauge in the instrument
cluster.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and at the correct coolant level,
the display may rise to the red mark. Display messages (vehicles with steering wheel buttons)
219
On-board computer and displays Z