coolant temperature MERCEDES-BENZ METRIS 2018 MY18 Operator’s Manual

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

Display messagesPossible causes/consequences andMSolutions
?The fan motor is faulty.
XCheckth e? coolan ttemperature gauge in th einstrumen tclus -
ter.
If th ecoolan ttemperature is belo wthemaximum value specified
below, you can continu edrivin gto th eneares tqualified specialist
workshop .
Avoid heav yloads on th eengine, e.g. drivin gin mountainous terrain ,
and stop-start traffic.
Under normal operating condition sand wit hth especified coolan t
level, th e? gauge may ris eto 24 8 ‡(120†).
+
CheckCoolan tLevelSee Oper. Manual
The coolan tlevel is to olow.
!Avoid making lon gjourneys wit hto olittl ecoolan tin th eengin e
coolin gsystem. The engin ewill otherwise be damaged.
XAd dcoolant, making sur eto observ eth ewarning note s
(Ypage 255).
XHav eth eengin ecoolin gsystem checke dat aqualified specialist
workshop if th ecoolan tneeds to be refilled mor eoften than usual.
4
CheckEngineOilAtNex tRefueling
XChec kth eoil level at th elatest when next refuelin g (Ypage 254).
XIf necessary, add engineoil (Ypage 255).
XHav eth eengin echecke dat aqualified specialist workshop if you
need to add engin eoil mor eoften than usual.
!Avoid lon gjourneys wit hto olittl eengin eoil. The engin ewill oth-
erwise be damaged.
4
Manually Check OilLevel
Reminder to chec kth eoil level.
XChec kth eoil level at th elatest when next refuelin g (Ypage 254).
XIf necessary, add engineoil (Ypage 255).
XTo confir mtheoil check :press a.
!Avoid lon gjourneys wit hto olittl eengin eoil. The engin ewill oth-
erwise be damaged.
4
Eng .OilLevelLow:StopVehicl eTur nEngine Off
The oil level is to olow. There is aris kof engin edamage.
XStop th evehicl eimmediately, payin gattention to roa dand traffic
conditions, and switch off th eengine.
XSecur eth evehicl eto preven tit from rollin gaway (Ypage 135).
XCheckth eoil level (Ypage 254).
XIf necessary, add engin eoil (Ypage 255).
æ
Fue lLevel Low
The fuel level has dropped to th ereserv erange.
XRefue lat th eneares tgas station .
ÏThere is ver ylittl efuel in th efuel tank.
XRefue lat th eneares tgas station without fail .
Display messages (vehicles withsteering whee lbu ttons)215
On-board computer and displays
Z

Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the transmission management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with a gasoline engine)
Rin the fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
XHave the vehicle checked as soon as possible at a qualified specialist workshop.
æN The yellow reserve fuel warning lamp is on while the engine is running.
The fuel level has dropped to the reserve range.
XRefuel at the nearest gas station.
?N The red coolant warning lamp comes on while the engine is running.
On vehicles without steering wheel buttons, the coolant temperature gage is at the
start of the bar display (
Ypage 175).
On vehicles with steering wheel buttons, the coolant temperature gage is at the
start of the scale in the instrument cluster (
Ypage 39).
The temperature sensor for the coolant temperature gage is faulty.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XStop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. Do not continue driving under any circumstances.
XSecure the vehicle to prevent it from rolling away (Ypage 135).
XConsult a qualified specialist workshop.
Indicator and warning lamps in the instrument cluster227
On-board computer and displays
Z

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

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
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)
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-
start traffic.
Under normal operating conditions and with the specified coolant level, the cool-
ant temperature gage may rise to 248 ‡ (120 †).
Driving systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
·NThe red distance warning lamp lights up while the vehicle is in motion.
The distance to the vehicle in front is too small for the speed selected.
XIncrease the distance.
·N The red distance warning lamp lights up while the vehicle is in motion. An
additional warning tone sounds.
You are approaching a vehicle or a stationary obstacle in your line of travel at too
high a speed.
XBe prepared to brake immediately.
XPay particular attention to the traffic situation. You may have to brake or take
evasive action.
Further information about the distance warning function can be found under
"COLLISION PREVENTION ASSIST" (
Ypage 146).
Indicator and warning lamps in the instrument cluster229
On-board computer and displays
Z

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

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

Rear axle
Operating fluid: transmission oil
Product name/numberMaintenanceinterval
Mobilube FE 75W-85
Mobilube FE Plus NG
75W-85
MB Sheet No. 235.7—
More information can be obtained at any quali-
fied specialist workshop.
Brake fluid
GWARNING
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.
!Brake fluid corrodes paint, plastic and rub-
ber. If paint, plastic or rubber has come into
contact with brake fluid, rinse with water
immediately.
When handling, storing and disposing of brake
fluid, please observe the relevant regulations
and the important safety notes for service prod-
ucts (
Ypage 306).
Over a period of time, the brake fluid absorbs
moisture from the air. This reduces its boiling
point.
Have the brake fluid replaced at specified inter-
vals by a qualified specialist workshop.
iThere is usually a notice in the engine com-
partment to remind you when the next brake
fluid change is due.
Use only approved brake fluids that comply with the Mercedes-Benz Specifications for Service
Products. Always check for the identification
DOT 4 plus. Information about approved brake fluids can be
obtained:
Ron the Internet at
http://bevo.mercedes-benz.co m.
Coolant
Important safety notes
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.
When handling, storing and disposing of coolant
and antifreeze, please observe the relevant reg-
ulations and the important safety notes for oper-
ating fluids (
Ypage 306).
Coolant additive with corrosion and
antifreeze protection
!Use only approved antifreeze/corrosion
inhibitor that complies with MB Specification for Service Products, Sheet Number 325.
Using other, non-approved antifreeze/corro-
sion inhibitors may cause damage to the cool-
ant system and reduce the engine's service
life.
The coolant is a mixture of water and antifreeze
and corrosion inhibitor. It performs the following
tasks:
RAnti-corrosion protection
RAntifreeze protection
RRaises the boiling point
When the vehicle is first delivered, it is filled with
a coolant mixture that ensures adequate anti-
freeze/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.
Service products and capacities311
Technical data
Z