radiator cap 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).
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

XHold support strut?and lift the hood
slightly.
XGuide support strut ?towards retainer =
and apply slight pressure to make it engage.
XLower the hood and allow it to fall with
momentum from a height of approximately
1 ft (30 cm).
The hood locks audibly.
XCheck that the hood is correctly locked.
If the hood can be raised slightly, it is not
properly engaged. If the hood is not correctly
engaged, open the hood again. Let the hood
fall with a little more momentum.
Overview of the engine compartment
Engine compartment (example)
:
Engine oil filler neck cap (Ypage 254)
;Brake fluid reservoir cap (Ypage 257)
=Coolant expansion tank cap (Ypage 255)
?Washer fluid reservoir cap (Ypage 258)
Regularly check the fluid level and the assembly
for leaks. If you detect fluid loss, e.g. oil stains
on the vehicle parking space, consult a qualified
specialist workshop immediately.
Engine oil
General notes
!Engine oil gets dirty in the course of opera-
tion and its quality and volume are gradually
diminished. Regularly check the oil level, and
top up or have it replaced as needed.
Observe the information on approved engine
oils and oil consumption under "Service prod-
ucts and capacities" (
Ypage 309). You can check the oil level in the engine:
Rwith the oil dipstick
Checking the oil level using the oil dip-
stick
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
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.
Oil dipstick and engine oil filler neck
Only check the oil level when the engine is at
normal operating temperature.
XStop your vehicle as far away from traffic as
possible on level ground.
XSecure the vehicle to prevent it from rolling
away.
XSwitch off the engine.
XWait for five minutes.
254Engine compartment
Maintenance and care

XOpen the hood (Ypage 253).
XPull out oil dipstick:.
XWipe oil dipstick:using a lint-free cloth.
XInsert oil dipstick :back into the guide tube
as far as it will go and remove it again.
If the level is between MIN mark =and MAX
mark ;, the oil level is adequate.
XIf the oil level has dropped to or below mini-
mum mark =, open cap ?and add engine oil
(
Ypage 255).
The difference in quantity between marks ;
and =is approximately 2 US quarts (2 liters).
XClose the hood.
Add engine oil
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
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
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil is not spilled next to
the filler neck. Let the engine cool down and
thoroughly clean the engine oil off the com-
ponents before starting the engine.
HEnvironmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful to
the environment.
!Do not add too much oil. adding too much
engine oil can result in damage to the engine
or to the catalytic converter. Have excess
engine oil siphoned off.
!Do not use any additives in the engine oil.
This could damage the engine.
Engine oil filler neck (example)
Observe the information regarding approved
motor oil under "Service products and capaci-
ties" (
Ypage 309).
XOpen the hood (Ypage 253).
XUnscrew and remove cap :.
XAdd engine oil.
XReplace cap:on the filler neck and tighten.
When doing so, make sure that the cap
engages correctly.
XCheck the oil level with the oil dipstick
(Ypage 254).
XClose the hood.
Coolant
GWARNING
Service products may be poisonous and haz-
ardous to health. There is a risk of injury.
Comply with instructions on the use, storage
and disposal of service products on the labels
of the respective original containers. Always
store service products sealed in their original
Engine compartment255
Maintenance and care
Z

containers. Always keep service products outof the reach of children.
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
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.
Coolant contains glycol and is therefore poison-
ous. Also observe the safety notes under "Ser-
vice products and capacities" (
Ypage 306).
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
Only check the coolant level and/or fill the cool-
ant if the vehicle is on a level surface and the
engine has cooled down. The coolant tempera-
ture must be below 122 ‡ (50 †).
!Check the engine cooling and heating sys-
tem regularly for leaks.
If a large quantity of coolant is lost, have the
cause traced and rectified at a qualified spe-
cialist workshop.
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.
!Take care not to spill any coolant on painted
surfaces. You could otherwise damage the
paintwork.
Example: cap and coolant expansion tankChecking the coolant level
XStop your vehicle as far away from traffic as
possible on level ground.
XSwitch off the engine.
XSecure the vehicle to prevent it from rolling
away.
XOpen the hood (Ypage 253).
XAllow the engine to cool down.
XUnscrew cap :slowly about half a turn coun-
ter-clockwise and allow excess pressure to
escape.
XTurn cap :further and remove it from cool-
ant expansion tank ;.
XCheck the coolant level.
If the coolant is up to marker bar =in the
filler neck when cold, there is a sufficient
amount of coolant in coolant expansion
tank ;.
If the coolant is approximately 0.59 in
(1.5 cm) above marker bar =in the filler neck
when warm, there is a sufficient amount of
coolant in coolant expansion tank ;.
256Engine compartment
Maintenance and care

Adding coolant
XIfthe coolant drops under marker bar=in
the filler neck, add coolant.
Observe the information on the correct cool-
ant mixture rat ioand the required water qual-
ity under "Service products and capacities"
(
Ypage 311). To prevent damage to the
engine co oling system, use only appr oved
corrosion inh ibitor/antifreeze that co mplies
wit h the Mercedes-Benz Specifications for
Service Products.
XReplac e cap:and tighten ina clock wise
dire ction.
XStart the engine.
XSet the temperature inthe veh icleinterior to
the maximum output on the air-conditioning
system control panel.
XAfter approximate lyfive minutes, switch off
the engine again and allow itto cool down.
XCheck the coolant level again and add coolant
ifnecessary.
XClose the hood.
Brake fluid
GWAR NING
Service products may be poisonous and haz-
ardous to health. There isa risk of injury.
Comp ly with instructions on the use, storage
and dispo sal of service products on the labels
of the respective original containers. Always
store service products sealed intheir original
containers. Always keep service products out
of the reach of ch ildren.
GWAR NING
Opening the hood when the engine isover-
heated or when there isa fire inthe engine
compartment could expose you to hot gases
or other service products. There isa risk of
injury.
Let an overheated engine cool downbefore
opening the hood. Ifthere isa fire inthe
engine compartment, keep the hood closed
and contact the fire department.
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 downand
touch only the components describe d in the
foll owin g.
Brake fluid is hazardous to health. Also observe the safety notes under "Service products and
capacities" (
Ypage 306).
GWARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. Ifthe boilin g 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.
!If the brake fluid level in the brake fluid res-
ervoir has fallen to the MIN mark or below,
check the brake system immediately for
leaks. Also check the thickness of the brake
linings. Visit a qualified specialist workshop
immediately.
Do not add brake fluid. This does not correct
the malfunction.
!Brake fluid corrodes paint, plastic and rub-
ber. Ifpaint, plastic or rubber has come into
contact with brake fluid, rinse with water
immediately.
Have the brake fluid renewed every two years at a qualified specialist workshop. Observe the
information regarding brake fluid in the "Service
products and capacities" section (
Ypage 311).
Engine compartment257
Maintenance and care
Z

Check the brake fluid level regularly, e.g. weekly
or when refueling.
Checking the brake fluid level
XStop your veh icleas far away from traff icas
possible on level ground.
XSwitch off the engine.
XSecure the veh icleto prevent itfrom rolling
away.
XOpen the hood (Ypage 253).
XCheck the brake fluid leve l.
The brake fluid level isadequate ifthe level is
between the MIN mark and MAX mark on
brake fluid reservoir :.
XClose the hood.
Washer fluid
GWARNING
Opening the hood when the engine isover-
heated or when there isa fire inthe engine
compartment could expose you to hot gases
or other service products. There isa risk of
injury.
Let an overheated engine cool downbefore
opening the hood. Ifthere isa fire inthe
engine compartment, keep the hood closed
and contact the fire department.
GWAR NING
Certain components inthe engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working inthe engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components describe d in the
following.
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There isa risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
!Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or MB WinterFit. Unsuitable washer fluid could dam-
age the plastic lenses of the headlamps.
Example :washe rfluid reservoir
Add wind shield washer concentrate to the
washer fluid all year round. Observe the infor-
mation regarding washer fluid under "Service
Products and Capacities" (
Ypage 313).
Adding washer fluid
XMix the washer fluid to the appropriate mixing
rat io in a container beforehand.
XOpen the hood (Ypage 253).
XPull cap :on the washer fluid reservoir
upwards at the tab.
XAdd the premixed washer fluid.
XPress cap :onto the filler neck until it
engages audibly.
XClose the hood.
258Engine compartment
Maintenance and care

Check the antifreeze/corrosion inhibitor con-
centration inthe coolant every six months.
The percentage of corrosion inh ibitor/ant i-
freeze additiveinthe engine co oling system
should:
Rbe at least 50 %.This way, the engine co oling
system isprotected against freezing downto
approximate ly-35 ‡ (-37 †).
Rnot exceed 55% (antifreeze protection down
to -49 ‡ [-45 †]). Other wise, heat will not be
dissipated as effectively.
Mercedes-Benz recommends an antifreeze and
corrosion inhibitor that meets the requirements
in the Mercedes-Benz Specifications for Service
Products Sheet Number 325.
More information can be obtained at any quali-
fied specialist workshop.
Operating fluid: coolant
Product name/number
Zerex G40-91, The Valvoline Company
MB Sheet No. 325.5
Maintenance interval
Have the coolant replaced at specified intervals
by a qualified specialist workshop.
Capacities
Engine cooling system
CoolantApprox. 11 US qt (10.4 l)
Climate control system refrigerants
Important safety notes
The climate control system of your vehicle is fil-
led with the refrigerant R‑ 134a.
The warning label for the refrigerant being used
can be found on the radiator cross member.
!Only the refrigerant R ‑134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
R-134a refrigerant. Otherwise, the climate
control system may be damaged. Maintenance work such as adding refrigerant or
replacing components may only be carried out
by a qualified specialist workshop. All applicable
regulations thereto and the SAE standard J639
must be adhered to.
All work on the climate control system should
always be carried out at qualified specialist
workshop.
Refrigerant warning label
Refrigerant warning label (example)
:
Warning symbols
;Refrigerant capacity
=Applicable standards
?Part number PAG oil
AType of refrigerant
Warning symbols :refer to:
Rpossible dangers
Rthe implementation of maintenance work at a
qualified specialist workshop
Capacities
Front-compartment
air-conditioning
systemCapacity
Refrigerant21.2 oz
(600 g)
PAG oil2.8 oz (79 g)
312Service products and capacities
Technical data