engine overheat MERCEDES-BENZ V-CLASS 2021 Owners Manual

R
hot vehicle parts do not come into
contact with 0ammable materials.
R theex haust gas can 0ow out of the
stationa ryheater exhaust pipe unhin-
dered.
R theex haust gas does not come into
contact with 0ammable materials. The heater
forth e auxiliary heating is /t tedatthe
front of theve hicle underbod y.The emissions out-
let is on the leT side of theve hicle below the front
door. &
W
WARNING
ARNING Risk of poisoning during work
on the auxiliary warm-air hea ter
If wo rkon the heat exch anger of the auxiliary
wa rm-air hea ter is not per form ed cor rectl y,
ex haust fumes could leak into the passenger
compartment. #
Have all workon the auxiliary warm-air
hea ter car ried out at a quali/ed specialist
wo rkshop. If
yo u are transporting hazardous materials, com-
ply with there leva nt sa fety regulations. Place
objects a su1cient distance from the auxiliary
heating outlet opening.
* N
NO OTE
TE Damage tothe auxiliary heating due
to ove rheating If
th e 0ow of hot air is bloc ked, the auxiliary
heating may overheat and switch o.. #
Do not block the 0ow of hot air. *
N
NOOTE
TE Battery dischar gecaused bystation-
ary heater or stationa ryventilation ope ra-
tion Operating
the stationary heater or stationary
ve ntilation drains the batter y. #
ATer heating or ventilating theve hicle
twice, drive for a longer period of time. Yo
ur vehicle may be equipped with either a hot-
wa ter auxiliary heater or an auxiliary warm-air
hea ter.
The ho hot-w
t-w at
ater auxiliar
er auxiliar y heat
y heat er
eris adjusted and
ope rated using the& rock er switch on the cli-
mate control system operating unit and via the
multimedia system or byremo tecont rol. The auxiliar
auxiliar y w
y war
arm-air heat
m-air heat er
eris adjusted and oper-
ated via the switch clock on the lo wer centre con-
sole. Ho
Ho
t-w
t-w at
ater auxiliar
er auxiliar y heat
y heat er
er F
F
unction of t
unction of t he ho
he hot-w
t-wat
ater auxiliar
er auxiliar y heat
y heater
er
Obser vethe no tes on auxiliary heating
(/ page 129).
The hot-water auxiliary heater has a heater boos-
te r,stationary heater and stationary ventilation
function.
The stationary hea ter automatically adapts its
operating mode tochanges in outside temp erature
and weather conditions. It is therefore possible
th at the stationary heater may switch from ventila-
tion toheating mode or from heating toventilation
mode.
The stationary hea ter will automatically switch
itself o. aTer a maximum of 50 minutes. The
heater booster function helps toheat up theve hi-
cle while the engine is running and at low outside
te mp eratures.
Yo u can set up tothre e departure times for pre-
entry climate control byremo tecont rol or via the
multimedia system. The switch-on time is then cal-
culated based on the outside temp erature and the
activated departure time. This means that your
ve hicle is preheated or precooled bythe set depar-
ture time.
If th e departure time is reached and theve hicle is
not star ted, the auxiliary heating will continue to
ru nfo r appr oximately /ve more minutes. It will
th en switch o. automaticall y.
When the auxiliary heating is heating and theve hi-
cle is star ted, the heater booster function of the
auxiliary heating will be activated.
When the auxiliary heating is ventilating and the
ve hicle is star ted, the auxiliary heating will be auto-
matically switched o.. 130 130
Climate control

*
N NO OTE
TE Damage totheve hicle due tonot
observing the maximum permitted head-
ro om clearance If
th eve hicle height is greater than the maxi-
mum permitted headroom clearance, thero of
and other parts of theve hicle may be dam-
aged. #
Obser vethe signposted headroom clear-
ance. #
Ifth eve hicle height is greater than the
permitted headroom clearance, do not
enter. #
Obser vethech anged vehicle height with
add-on roof equipment. N No
ot
tes on shor
es on shor t-dist
t-distance tr
ance tr ips
ips
If th eve hicle is predominantly used in short-dis-
ta nce driving, a fault in the automatic cleaning
function of the diesel particulate /lter can occur.
Due tothis, fuel may also accumulate inthe engine
oil and cause engine failure.
During automatic cleaning, extremely hot exhaust
ga ses escape from theex haust pipe. Main tain a
distance of at least 1 m toother objects, e.g.
par kedve hicles, in order toavo id material damage.
If yo u mainly drive short distances, you should
drive on a mo torw ay or go for a country drive for
20 minutes every 500 km. This facilitates the
re ge neration of the diesel particulate /lter.
Inf
Inf or
ormation about tr
mation about tr anspor
ansport b
t by r
y rail
ail
Tr ansporting your vehicle byrail may be subject to
cer tain restrictions or requ ire special measures to
be take n in some countries due tovarying tunnel
heights and loading standards.
Yo u can obtain information about this from a
Mercedes-Benz Service Centre.
Inf
Inf or ormation on br
mation on br ak
ak es
es &
W
WARNING
ARNING Risk of accident due tothe
brake system overheating
If yo u lea veyour foot on the brake pedal when
driving, the brake system may overheat.
This increases the braking distance and the
brake system can even fail. #
Never use the brake pedal as a foot re st. #
Do not depress the brake pedal and the
accelerator pedal at the same time while
driving. *
N NOOTE TE Causing wearto the brake linings by
permanently depressing the brake pedal #
Do not permanently depress the brake
pedal while driving. #
Touse braking e.ect of the engine, shiT
to a lo werge ar in good time. Do
Do
wnhill gr
wnhill gradients
adients
On long and steep downhill gradients you should
obser vethefo llowing inst ructions:
R invehicles with an automatic transmission,
shiT down toshiT ranges 2 2or 1 1in good time
so that the engine is running at a medium to
high engine speed (/ page 143).
R invehicles with a manual transmission, shiT
down toa lo werge ar in good time, so that the
engine is running at a medium tohigh engine
speed.
% Change the shiT range in good time when
cruise control or the limiter are activated.
Obser vethe driving tips (/ page 137).
Yo uth ereby make use of the braking e.ect of the
engine and do not ha vetobrake as oTen tomain-
ta in the speed. This relie vesth e load on the
service brake and pr events the brakes from over-
heating and wearing tooqu ickl y.
Hea
Hea vy and light loads
vy and light loads
If th e brakes ha vebeen subjected toa heavy load,
do not stop theve hicle immediatel y.Drive on for a
short while. The brakes cool down more quickly in
th e air0o w.
If th e brakes ha vebeen used only moderatel y,you
should occasionally test their e.ectiveness. Todo
th is, brake more /rmly from a higher speed while
paying attention tothe tra1c conditions. The
brakes will grip better as a result.
We
We t r
t road surf
oad surf aces
aces
If yo u ha vebeen driving for a long time in heavy
ra in without braking, there may be a dela yed
re sponse when you /rst apply the brakes. This may
also occur aTer driving thro ugh a car wash or deep
wa ter. Yo u must depress the brake pedal more
/rml y.Maintain a greater distance totheve hicle in
front.
While paying attention tothe tra1c conditions, you
should brake theve hicle /rml yaTer driving on a
we tro ad sur face or thro ugh a car wash. This heats
th e brake disks so that they dry more quickl y,
which pr otects them against cor rosion. 138 138
Driving and parking

#
Before you open the fuel /ller cap or take
hold of the pump nozzle, touch the met-
allic vehicle body. #
Toavo id creating ano ther electrostatic
ch arge , do not get into theve hicle again
during there fuelling process. &
W
WARNING
ARNING Risk of /re from fuel mixtu re
Ve hicles with a diesel engine:
If yo u mix diesel fuel with petrol, the 0ash point
of the fuel mixture is lo werth an that of pure
diesel fuel.
While theve hicle is running, component parts
in theex haust system may overheat without
wa rning. #
Neverre fuel using petrol. #
Never mix petrol with diesel fuel. *
N NOOTE
TE Do not use diesel torefuel vehicles
with a petrol engine If
yo u ha veacciden tally refuelled wi th the
wrong fuel:
R Do not switch on theve hicle. Otherwise
fuel can enter the engine.
Even small amounts of the wrong fuel
could result in damage tothe fuel system
and the engine. The repair costs are high. #
Consult a quali/ed specialist workshop. #
Have the fuel tank and fuel lines drained
comple tely. *
N
NO
OTE
TE Do not use petrol torefuel vehicles
with a diesel engine If
yo u ha veacciden tally refuelled wi th the
wrong fuel:
R Do not switch on theve hicle. Otherwise,
fuel can enter the fuel system.
Even small amounts of the wrong fuel
could result in damage tothe fuel system
and the engine. The repair costs are high. #
Consult a quali/ed specialist workshop. #
Have the fuel tank and fuel lines drained
comple tely. *
N
NO
OTE
TE Damage tothe fuel system caused
by ove r/lled fuel tanks #
Only /ll the fuel tank until the pump noz-
zle switches o.. R
R
eq
eq uir
uir ements:
ements:
R The vehicle is unloc ked and switched o..
R The auxiliary heating is switched o..
R The front leT-hand door is open.
% Do not getback into theve hicle during the
re fuelling process. Othe rwise, electrostatic
ch arge could build up again.
Obser vethe no tes on operating 0uids
(/ page 271). #
Open fuel /ller 0ap 1. #
Turn fuel /ller cap 2anti-clockwise and
re mo veit. #
Close all vehicle doors topreve nt fuel vapours
from entering theve hicle interior. #
Comple tely slide the /ller neck of the pump
nozzle into theta nk, hook in place and refuel. #
Fillth e fuel tank only until the pump nozzle
switches o.. #
Replace fuel /ller cap 2and turn it clockwise.
Yo u will hear a click when the fuel /ller cap is
closed full y. #
Open the front leT-hand door. #
Close fuel /ller 0ap 1.
% V
Vehicles wit
ehicles wit h a diesel engine and incorr
h a diesel engine and incorr ect
ect
fuelling pr ot
fuelling prot ect
ector ag
or ag ains
ainst rt refuelling wit
efuelling wit h pe
h pet-
t-
r
r ol:
ol: the /ller neck is designed forre fuelling at
diesel /lling pumps for passenger vehicles. Driving and parking
147
147

N
N
o
ot
tes on loading guidelines
es on loading guidelines &
D
DAN
AN GER
GER Risk of poisoning from exhaust
ga ses
Combustion engines emit poisonous exhaust
ga ses, such as carbon monoxide. Exhaust
ga ses can enter theve hicle interior if theta il-
ga te is open when theve hicle is running, espe-
cially if theve hicle is in motion. #
Always switch o. theve hicle before
opening theta ilgate. #
Never drive with theta ilgate open. &
W
WARNING
ARNING Risk of injury from unsecured
objects in theve hicle
When objects are unsecured or inadequately
secured, they can slip, tip over or be thro wn
about, st riking vehicle occupants.
This also applies to:
R luggage or loads
R seats which ha vebeen remo ved and are
being transpor ted in theve hicle in an
ex ceptional case
There is a risk of injur y,particular lyin the
eve nt of braking manoeuvres or abrupt
ch anges in direction. #
Always st owobjects in such a wayth at
th ey cannot be tossed about. #
Before tr avelling, secure objects, luggage
or load toprev ent them slipping or tip-
ping over. #
When a seat is remo ved, keep it prefera-
bly outside theve hicle. &
W
WARNING
ARNING Risk of accident due toincor-
re ctly placed load
The cent reofgrav ity of the load may be too
high and/or toofar bac k.
This can signi/cantly impair the driving, steer-
ing and braking characteristics. #
Always ensu rethat the centre of grav ity
of the load is between the axles and as
low as possible near there ar axle. &
W
WARNING
ARNING Risk of accident due toexceed-
ing the permissible wheel/axle loads or
th egr oss vehicle weight
The driving characteristics, as well as steering
and braking, may be greatly impaired. Overloa-
ded tyres may overheat and burst as a conse-
qu ence. #
When transporting a load, alw ays
obser vethe permissible wheel loads,
axle loads and the maximum permissible
gr oss mass forth eve hicle (including
occupants). &
W
WARNING
ARNING Risk of injury if unsuitable
climbing aids are used
In theeve ntthat you use openings in the body-
wo rkor attachments as steps, you could:
R Slip and/or fall.
R Damage theve hicle and thus slip and fall. #
Always use non-slip, stable climbing aids,
e.g. a suitable ladder. *
N
NOOTE
TE Damage caused bythe use of open-
ings in the bodywork or de tach able part as
a step Using
the lo wer guide of the sliding door (car-
ri age) as a step can damage the trim and/or
mechanism of the sliding door. #
Do not use the guide of the sliding door
(car riage) as a step. If
yo u are using a roof luggage rack , please no te
th e maximum roof load and the maximum load
capacity of thero of luggage rack ( /page 280).
The handling characteristics of your vehicle are
dependent on the load distribution.
Therefore, please obser vethefo llowing no tes
when loading:
R the load must not pr otru de abo vethe upper
edge of the seat backrests.
R if possible, alw ays transport the load in the
load compartment.
R fasten the load tothe tie-down eyes and dis-
tribute the load evenly among them. 214
214
Tr
anspo rting

Coolant
Coolant
N
No
ot
tes on coolant
es on coolant
Obser vethe no tes on operating 0uids
(/ page 271). &
W
W ARNING
ARNING Risk of /re‑ and injury from
antifreeze
If antifreeze comes into contact with hot com-
ponent parts in the engine compartment, it
may ignite. #
Allow theve hicle tocool down before
yo uto p up the antifreeze. #
Make sure that no antif reeze spills out
next tothe /ller opening. #
Thoroughly clean the antifreeze from
component parts before starting the
ve hicle. *
N
NOOTE
TE Damage caused byincor rect cool-
ant #
Only add coolant that has been premixed
with there qu ired antifreeze pr otection. Information on coolant is
available at thefo llowing
locations:
R Inthe Mercedes-Benz Speci/cation for Operat-
ing Fluids 320.1
- Athttps://be vo.mercedes-benz.com
- Inthe Mercedes-Benz BeVo app
R Ataqu ali/ed specialist workshop
* N
NOOTE
TE Overheating at high outside temp er-
atures If an inappropriate coolant is used,
the engine
cooling system is not su1cient lyprotected
against overheating and cor rosion at high out-
side temp eratures. #
Always use coolant appr ovedby
Mercedes-Benz . #
Obser vethe inst ructions in the
Mercedes-Benz Speci/cations for Oper-
ating Fluids 320.1. *
N
NOOTE
TE Paintwork damage due tocoolant #
Do not spill coolant on painted sur faces. Ha
ve the coolant regular ly replaced at a quali/ed
specialist workshop. No
tethe proportion of anti-cor rosion agent/anti-
freeze in the engine cooling system within thefo l-
lowing temp erature ranges:
R A minimum of 50% (antifreeze pr otection down
to about -37°C)
R A maximum of 55% (antifreeze pr otection down
to -45°C)
Capacities, coolant
Capacities, coolant
Engine cooling syst Engine cooling syst em
em Model
Model
Capacity
Capacity
All models Approx. 10.4 l
Appr ox. 13.4 l
on vehicles with auxili-
ary heating W
W
indscr
indscr een w
een washer
asher 0uid
0uid N
No
ot
tes on windscr
es on windscr een w
een washer
asher 0uid
0uid
Obser vethe no tes on operating 0uids
(/ page 271). &
W
WARNING
ARNING ‑ Risk of /re and injury due to
windscreen washer concentrate
Wi ndsc reen washer concentrate is highly 0am-
mable. It could ignite if it comes into contact
with hot engine component parts or the
ex haust system. #
Make sure that no windscreen washer
concentrate spills out next tothe /ller
opening. *
N
NOOTE
TE Damage totheex terior lighting due
to unsuitable windscreen washer 0uid Unsuitable windscreen
washer 0uids may dam-
age the plastic sur face of theex terior lighting. #
Only use windscreen washer 0uids which
are also suitable for use on plastic sur fa-
ces, e.g. MB SummerFit or MB WinterFit. *
N
NOOTE
TE Bloc ked spr aynozzles caused by
mixing windscreen washer 0uids #
Do not mix MB SummerFit and MB Win-
te rFit with other windscreen washer 0u-
ids. Do not use distilled or de-ionised
water. Otherwise,
th e /ll le vel sensor may give a false reading. Te
ch nical data
277
277

Displa
Displa
y messag
y messag es P
es P ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions #
Drive in a manner appropriate forth e cur rent le vel, but do not
ex ceed 80 km/h. #
Consult a quali/ed specialist workshop. Engine
Engine
Displa
Displa
y messag
y messag es P
es P ossible causes/conseq
ossible causes/conseq uences and
uences andM
MSolutions
Solutions
# See Owner's Manual *A
warning tone also sounds.
The bat tery is no longer being charge dfo r one of thefo llowing rea-
sons:
R defecti vealternator
R torn pol y-V belt
R malfunction in the electronics #
Stop theve hicle immediately in accordance with the tra1c condi-
tions and switch it o..
Do not continue driving. If you do, the engine may overheat. #
Secure theve hicle against rolling away. #
Consult a quali/ed specialist workshop.
! Clean the fuel filter *T
here is water in the fuel /lter. The water must be drained o.. #
Consult a quali/ed specialist workshop.
? Coolant Stop vehicle
Switch engine off *A
warning tone also sounds. The coolant is too hot. &
W WARNING
ARNING Risk of burns when opening the bonnet
If yo u open the bonnet in theev ent of an overheated engine or /re
in the engine compartment, thefo llowing situations may occur:
R You may come into contact with hot gases.
R You may come into contact with other escaping hot operating
0uids. #
Before opening the bonnet, allow the engine tocool down. #
Intheev ent of a /re in the engine compartment, keep the
bonnet closed and call the /re service. &
W
WARNING
ARNING Risk of scalding from hot coolant
If yo u open the cap, you could be scalded. #
Letthe mo tor cool down before opening the cap. #
When opening the cap, wear pr otective glo ves and saf ety
glasses. #
Open the cap slo wlytorelease pressure. #
Stop theve hicle immediately in accordance with the tra1c condi-
tions and switch it o.. Display messages and
warning and indicator lamps
295
295

K
K
e
ey
y Displa
Displa
y messag
y messag es P
es P ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
 Key does not belong to
vehicle *Y
ou ha veinser ted an incor rect key in tothe ignition loc k. #
Use the cor rect key.
 Remove key *T
hekey is in the ignition loc k. #
Remo vethekey.
Â
Replace key *T
hekey needs tobe replaced. #
Consult a quali/ed specialist workshop.
 Change key batteries *T
hekey battery is dischar ged. #
Replace the battery (/ page 52). V V
ehicle
ehicle Displa
Displa
y messag
y messag es P
es P ossible causes/conseq
ossible causes/conseq uences and
uences andM
MSolutions
Solutions
Clutch overheated Avoid
pulling away Engage/
disengage clutch quickly
if req. *A
warning tone also sounds. The clutch is under heavy load and the
permissible operating temp erature of the clutch has been exceeded.
Av oid frequent pulling away and driving at walking pace overex tended
distances. #
Stop in accordance with the tra1c conditions. #
Secure theve hicle against rolling away. #
Leavethe engine running.
The clutch will cool more quickly when the engine is running.
or #
If possible, continue driving at a steady speed. #
Remo ve yo urfoot from the clutch pedal and do not let the clutch
slip.
The clutch may also cool down during driving.
Cooling down can take afew minutes. When the clutch has cooled
down, the display message will disappear and the clutch will be fully
operational again.
Ò *T
hetailgate is open. #
Close theta ilgate. 300 300
Display message
s andwarning and indicator lamps

Displa
Displa
y messag
y messag es P
es P ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions #
Tocontinue your journe y,shiT the transmission toposition kor
h.
Risk of vehicle rolling
Vehicle not in P *A
warning tone also sounds. The driver's door is open and the trans-
mission is in position i,korh. #
ShiT the transmission toposition j. #
Secure theve hicle against rolling away.
Without changing gear,
consult workshop *A
warning tone also sounds. You can no longer change the transmis-
sion position due toa malfunction.
If transmission position hhas been selected: #
Without changing the transmission position, consult a quali/ed
specialist workshop.
If transmission position j,kori has been selected: #
Inform a quali/ed specialist workshop.
Reversing not poss. Con-
sult workshop *T
he transmission is malfunctioning. Transmission position kcann ot
be selected. #
Inform a quali/ed specialist workshop.
Transmission Malfunc-
tion Stop *T
he transmission is malfunctioning. The transmission automatically
switches toneutral i. #
Stop theve hicle immediately in accordance with the tra1c condi-
tions. #
ShiT the transmission toposition j. #
Inform a quali/ed specialist workshop.
Stop vehicle Leave
engine running Wait
Transmission cooling *T
he transmission is overheating. Pulling away may be temp orarily
impaired or not possible. #
Stop theve hicle immediately in accordance with the tra1c condi-
tions. Do not continue driving! #
Leavethe engine running. #
Wait until the display message disappears before pulling away.
&
inoperative Battery low *T
he on-board elect rical system voltage is too lo w.The hot-water auxili-
ary hea ter (stationary heater) has switched itself o. or cannot be
switched on. #
Drive for an extended distance.
The bat tery will be charge d. The hot-water auxiliary heater (sta-
tionary heater) will be operational again as soon as the on-board
electrical system voltage is su1cient.
& inoperative Refuel vehi-
cle *T
here is too little fuel in the fuel tank. The hot-water auxilia ryheater
(stationary heater) cann otbe switched on. #
Refuel theve hicle. 302 302
Display messages and
warning and indicator lamps

W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions #
Stop theve hicle immediately in accordance with the tra1c condi-
tions and switch it o.. #
Secure theve hicle against rolling away. #
Exit theve hicle and keep a safe distance from it until the engine has
cooled down. #
Check the coolant le vel and top up with coolant, complying with the
inst ructions (/ page 228). #
Ifth e coolant has tobe topped up frequentl y,ha ve the engine cool-
ing system checked at a quali/ed specialist workshop. #
Ensure that the air supply tothera diator is not impaired, e.g. by a
plastic bag that has been blown onto thegr ille. #
Monitor the coolant temp erature display on the inst rument cluster. #
Do not restart the engine until the coolant temp erature is below
120°C. If you do, the engine may be damaged. #
Drive on tothe nearest quali/ed specialist workshop. Avoid high
engine loads, e.g. driving in mountainous terrain or stop-and-go
driving.
?
Coolant warning lamp *The
red coolant warning lamp is on while theve hicle is on. A warning
to ne also sounds.
The coolant has exceeded thete mp erature of 120°C. The air supply to
th era diator may be impaired or the coolant le vel may be too lo w.
The engine has not been su1cient lycooled and may be damaged. &
W
WARNING
ARNING Risk of burns when opening the bonnet
If yo u open the bonnet in theev ent of an overheated engine or /re
in the engine compartment, thefo llowing situations may occur:
R You may come into contact with hot gases.
R You may come into contact with other escaping hot operating
0uids. #
Before opening the bonnet, allow the engine tocool down. #
Intheev ent of a /re in the engine compartment, keep the
bonnet closed and call the /re service. #
Pay attention tothe display messages. #
Stop theve hicle immediately in accordance with the tra1c condi-
tions and switch it o.. #
Secure theve hicle against rolling away. #
Exit theve hicle and keep a safe distance from it until the engine has
cooled down. #
Check the coolant le vel and top up with coolant, complying with the
inst ructions (/ page 228). #
Ifth e coolant has tobe topped up frequentl y,ha ve the engine cool-
ing system checked at a quali/ed specialist workshop. #
Ensure that the air supply tothera diator is not impaired, e.g. by a
plastic bag that has been blown onto thegr ille. 310
310
Display message
s andwarning and indicator lamps