2020 MERCEDES-BENZ METRIS radiator cap

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).Engine compartment
Hood
Important safety notes G
WARNING
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. 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. G
WARNING
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:
R switch off the ignition
R never reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
R remove jewelry and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts G
WARNING
The ignition system operates with a high
voltage. 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:
R the engine is running or being started
R the key is in radio position or drive posi-
tion in the ignition lock
The live components of the ignition system
are, for example:
R ignition coils
R spark plug connectors
R diagnostic sockets G
WARNING
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
compartment, only touch the following compo-
nents:
R hood
R oil dipstick
R engine oil filler neck cap
R washer fluid reservoir cap
R coolant expansion tank cap250
Engine compartment
Maintenance and care

X
Hold support strut ? and lift the hood
slightly.
X Guide support strut ? towards retainer =
and apply slight pressure to make it engage.
X Lower the hood and allow it to fall with
momentum from a height of approximately
1 ft (30 cm
).
The hood locks audibly.
X Check that the hood is correctly locked.
If the hood can be raised slightly, it is not
properly engaged. If the hood is not cor-
rectly engaged, open the hood again. Let
the hood fall with a little more momentum. Overview of the engine compart-
ment
Engine compartment (example)
:
Engine oil filler neck cap (Y page
252)
; Brake fluid reservoir cap (Y page
255)
= Coolant expansion tank cap ( Y page
253)
? Washer fluid reservoir cap (Y page
256)
Regularly check the fluid level and the assem-
bly 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" ( Y page

308).You can check the oil level in the engine:
R with the oil dipstick
Checking the oil level using the oil dip-
stick 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. G
WARNING
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. X Stop your vehicle as far away from traffic as
possible on level ground.
X Secure the vehicle to prevent it from rolling
away.
X Switch off the engine.
X Wait for five minutes.252
Engine compartment
Maintenance and care

X
Open the hood (Y page 251).
X Pull out oil dipstick :.
X Wipe oil dipstick : using a lint-free cloth.
X Insert 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.
X If the oil level has dropped to or below mini-
mum mark =, open cap ? and add engine
oil

(Y page 253).
The difference in quantity between
marks ; and = is approximately
2 US quarts (2 liters).
X Close the hood.
Adding engine oil 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. G
WARNING
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. G
WARNING
If engine oil comes into contact with hot
components 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
components before starting the engine. H
Environmental 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" (Y page

308).
i When releasing the hood, the key must be
inserted in the ignition lock and in position 0
– ignition off.
X Open the hood (Y page
251).
X Unscrew and remove cap :.
X Add engine oil.
X Replace cap : on the filler neck and
tighten.
When doing so, make sure that the cap
engages correctly.
X Check the oil level with the oil dipstick
(Y page

252).
X Close the hood. Coolant
G
WARNING
Service products may be poisonous and haz-
ardous to health. There is a risk of injury. Engine compartment
253
Maintenance and care
Z

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 containers. Always keep service
products out of the reach of children. 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. G
WARNING
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 poi-
sonous. Also observe the safety notes under
"Service products and capacities"
(Y page
305). G
WARNING
The cooling system is pressurized, particu-
larly 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 protective gloves and protec-
tive eyewear when opening. Open the cap
slowly to release pressure.
Only check the coolant level and/or fill the
coolant if the vehicle is on a level surface and
the engine has cooled down. The coolant tem-
perature must be below

122 ‡ (50 †). The
coolant temperature gauge must no longer reach the first line after the letter
C on the
scale and/or the bar display.
! 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. G
WARNING
If antifreeze comes into contact with hot
components in the engine compartment, it
may ignite. There is a risk of fire and injury.
Let the engine cool down before you add
antifreeze. 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 pain-
ted surfaces. You could otherwise damage
the paintwork. Example: cap and coolant expansion tank
Checking the coolant level
X Stop your vehicle as far away from traffic as
possible on level ground.
X Switch off the engine.
X Secure the vehicle to prevent it from rolling
away.
X Open the hood (Y page
251).
X Allow the engine to cool down.
X Unscrew cap : slowly about half a turn
counter-clockwise and allow excess pres-
sure to escape. 254
Engine compartment
Maintenance and care

X
Turn cap : further and remove it from cool-
ant expansion tank ;.
X Check 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 ;.
Adding coolant X If the coolant drops under marker bar = in
the filler neck, add coolant.
Observe the information on the correct cool-
ant mixture ratio and the required water
quality under "Service products and capaci-
ties" ( Y page

310). To prevent damage to
the engine cooling system, use only
approved corrosion inhibitor/antifreeze that
complies with the Mercedes-Benz Specifica-
tions for Service Products.
X Replace cap : and tighten in a clockwise
direction.
X Start the engine.
X Set the temperature in the vehicle interior to
the maximum output on the air-conditioning
system control panel.
X After approximately five minutes, switch off
the engine again and allow it to cool down.
X Check the coolant level again and add cool-
ant if necessary.
X Close the hood. Brake fluid
G
WARNING
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 containers. Always keep service
products out of the reach of children. 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. G
WARNING
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.
Brake fluid is hazardous to health. Also
observe the safety notes under "Service prod-
ucts and capacities"
(Y page 305). G
WARNING
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.
! If the brake fluid level in the brake fluid
reservoir 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 cor-
rect the malfunction.
! Brake fluid corrodes paint, plastic and rub-
ber. If paint, plastic or rubber has come into
contact with brake fluid, rinse with water
immediately. Engine compartment
255
Maintenance and care Z

Have the brake fluid renewed every two years
at a qualified specialist workshop. Observe the
information regarding brake fluid in the "Ser-
vice products and capacities" section
(Y page
310).Check the brake fluid level regularly, e.g.
weekly or when refueling.
Checking the brake fluid level
X Stop your vehicle as far away from traffic as
possible on level ground.
X Switch off the engine.
X Secure the vehicle to prevent it from rolling
away.
X Open the hood (Y page
251).
X Check the brake fluid level.
The brake fluid level is adequate if the level
is between the MIN mark and MAX mark on
brake fluid reservoir :.
X Close the hood. Washer fluid
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. G
WARNING
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. G
WARNING
Windshield washer concentrate is highly
flammable. If windshield washer concentrate
gets onto hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure that windshield washer concen-
trate is not spilled in the vicinity of the filler
neck.
! Only use washer fluid which is suitable for
lamp lenses, e.g. MB SummerFit or MB Win-
terFit. Unsuitable washer fluid may damage
the lamp lenses of the headlamps. Example: washer fluid reservoir
Add windshield washer concentrate to the
washer fluid all year round. Observe the infor-
mation regarding washer fluid under "Service
Products and Capacities"

(Y page 312).
Adding washer fluid
X Mix the washer fluid to the appropriate mix-
ing ratio in a container beforehand.
X Open the hood ( Y page
251).
X Pull cap : on the washer fluid reservoir
upwards at the tab.
X Add the premixed washer fluid.
X Press cap : onto the filler neck until it
engages audibly.
X Close the hood.256
Engine compartment
Maintenance and care

the coolant system and reduce the engine's
service life.
The coolant is a mixture of water and anti-
freeze and corrosion inhibitor. It performs the
following tasks:
R Anti-corrosion protection
R Antifreeze protection
R Raises the boiling point
When the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze/corrosion protection. Coolant must
remain in the engine cooling system all year
round to ensure anti-corrosion protection and
a higher boiling point, even in countries with
high outside temperatures.
Check the antifreeze/corrosion inhibitor con-
centration in the coolant every six months.
The percentage of corrosion inhibitor/anti-
freeze additive in the engine cooling system
should:
R be at least
50%. This way, the engine cooling
system is protected against freezing down
to approximately -35 ‡ (-37 †).
R not exceed 55% (antifreeze protection down
to -49 ‡ [-45 †]). Otherwise, heat will not
be dissipated as effectively.
Mercedes-Benz recommends an antifreeze and
corrosion inhibitor that meets the require-
ments 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 inter-
vals by a qualified specialist workshop.
Capacities Engine cooling system
Coolant
Approx. 11 US qt
(10.4 l
) Climate control system refrigerants
Important safety notes The climate control system of your vehicle is
filled with the refrigerant R ‑134a.
The warning label for the refrigerant being
used can be found on the radiator cross mem-
ber.
! 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 dam-
aged.
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
A Type of refrigerant
The symbol : refers to:
R possible dangers
R the implementation of maintenance work at
a qualified specialist workshop Service products and capacities
311
Technical data Z