engine overheat MERCEDES-BENZ E320 2001 W210 Owner's Manual

90 Instrument cluster
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Coolant temperature gauge (3)
During severe operating conditions and stop-and-go city
traf f ic, th e coola nt tempera ture may rise close to th e red
marking.
The engine should not be operated with the coolant
temperature in the red zone. Doing so may cause
serious engine damage which is not covered by the
Mercedes-Benz Limited Warranty.Outside temperature indicator (5)
The temperature sensor is located in the front bumper
area. Due to its location, the sensor can be affected by
road or engine heat during idling or slow driving. This
means that the accuracy of the displayed temperature
can only be verified by comparison to a thermometer
placed next to the sensor, not by comparison to external
displays (e.g. bank signs etc.).
Adaption to ambient temperature takes place in steps
and depends on the prevailing driving conditions
(stop-and-go or moderate, constant driving) and amount
of temperature change.
Wa r n i n g !
• Driving when your engine is badly overheated
can cause some fluids which may have leaked
into the engine compartment to catch fire. You
could be seriously burned.• Steam from an overheated engine can cause
serious burns and can occur just by opening
the engine hood. Stay away from the engine if
you see or hear steam coming from it.Turn off the engine, get out of the vehicle and do
not stand near the vehicle until it cools down.
Wa r n i n g !
The outside temperature indicator is not designed
to serve as an Ice-Warning Device and is therefore
unsuitable for that purpose. Indicated
temperatures just above the freezing point do not
guarantee that the road surface is free of ice.

188 Catalytic converter
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Catalytic converter
Your Mercedes-Benz is equipped with monolithic type
catalytic converters, an important element in
conjunction with the oxygen sensors to achieve
substantial control of the pollutants in the exhaust
emissions. Keep your vehicle in proper operating
condition by following our recommended maintenance
instructions as outlined in your Service Booklet.
Caution!
To prevent damage to the catalytic converters, use only
premium unleaded gasoline in this vehicle.
Any noticeable irregularities in engine operation should
be repaired promptly. Otherwise, excessive unburned
fuel may reach the catalytic converter causing it to
overheat, which could start a fire.
Wa r n i n g !
As with any vehicle, do not idle, park or operate
this vehicle in areas where combustible materials
such as grass, hay or leaves can come into contact
with the hot exhaust system, as these materials
could be ignited and cause a vehicle fire.

204 Driving instructions
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Power assistance
BrakesThe condition of the parking brake system is checked
each time the vehicle is in the shop for the required
maintenance service.
If the parking brake is released and the brake warning
lamp in the instrument cluster stays on, the brake f luid
level in the reservoir is too low.
Brake pad wear or a leak in the system may be the
reason for low brake f luid in the reservoir.
Have the brake system inspected at an authorized
Mercedes-Benz Center immediately.
Al l checks and service work on the brake system shoul d
be carried out by an authorized Mercedes-Benz Center.
Install only brake pads and brake fluid recommended by
Mercedes-Benz.
Wa r n i n g !
When the engine is not running, the brake and
steering systems are without power assistance.
Under these circumstances, a much greater effort is
necessary to stop or steer the vehicle.Wa r n i n g !
After driving in heavy rain for some time without
applying the brakes or through water deep enough
to wet brake components, the first braking action
may be somewhat reduced and increased pedal
pressure may be necessary to obtain expected
braking effect. Be sure to maintain a safe distance
from vehicles in front.Resting your foot on the brake pedal will cause
excessive and premature wear of the brake pads.It can also result in the brakes overheating thereby
significantly reducing their effectiveness. It may
not be possible to stop the vehicle in sufficient time
to avoid an accident.
Wa r n i n g !
If other than recommended brake pads are
installed, or other than recommended brake fluid
is used, t he braking properties of th e vehic le can be
degraded to an extent that safe braking is
substantially impaired. This could result in an
accident.

205 Driving instructions
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Caution!
When driving down long and steep grades, relieve the
load on the brakes by shifting into a lower gear to use
the engine’s braking power. This helps prevent
overheating of the brakes and reduces brake pad wear.
After hard braking, it is advisable to drive on for some
time, rather than immediately parking, so the air stream
will cool down the brakes faster.
Driving off
Apply the service brakes to test them briefly after
driving off. Perform this procedure only when the road
is clear of other traffic.
Warm up the engine smoothly. Do not place full load on
the engine until the operating temperature has been
reached.
W hen sta rting of f on a sl ippery surfa ce, d o not al low one
drive wheel to spin for an extended period with the ESP
switched off. Doing so may cause serious damage to the
drive train which is not covered by the Mercedes-Benz
Limited Warranty.Parking
Important!
It is advisable to set the parking brake whenever
parking or leaving the vehicle. In addition, move
selector lever to position “P”.
When parking on hills, always set the parking brake.
Wa r n i n g !
To reduce the risk of personal injury as a result of
vehicle movement, before
turning off the engine
and leaving the vehicle, always:
1. Keep right foot on the service brake pedal.
2. Firmly depress parking brake pedal.
3. Move the selector lever to position “P”.
4. Slowly release the service brake pedal.
5. Turn front wheels towards the road curb.
6. Turn the electronic key to steering lock
position 0 and remove.
7. Take the electronic key and lock vehicle when
leaving.

241 Malfunction and warning messages
Technical
data Instruments
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cluster displayPractical hints Car care Index BATTERY / ALTERNATORThis message indicates a malfunction which must be
repaired immediately.
It may indicate that the poly-V-belt has broken. Should
this condition occur, the poly-V-belt must be replaced
before continuing to operate the vehicle. Otherwise, the
engine will overheat due to an inoperative water pump
which may result in damage to the engine.
Do not continue to drive the vehicle with this message
displayed.
Doing so could result in serious engine damage that is
not covered by the Mercedes-Benz Limited Warranty.
Line 1 Line 2
BATTERY / ALTERNATOR VISIT WORKSHOP!
OVERVOLTAGE V ISIT WORKS HOP!
UNDERVOLTAGE CONSUMER DEFECTIVE!

245 Malfunction and warning messages
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index COOLANT (coolant level)
When this message appears while driving, the coolant
level has dropped below the required level. If no leaks
are noticeable and the engine temperature does not
increase, continue to drive to the nearest service station
and have coolant added to the coolant system.The low engine coolant level warning should not be
ignored. Extended driving with the symbol displayed
may cause serious engine damage not covered by the
Mercedes-Benz Limited Warranty.
In cases of major or frequent minor coolant loss, have
the cooling system checked at your authorized
Mercedes-Benz Center as soon as possible.
Notes:
Do not drive without coolant in the cooling system. The
engine will overheat causing major engine damage.
Monitor the coolant temperature gauge while driving,
see page 90.
See page 261 for instructions on topping up the coolant.
Line 1 Line 2
COOLANT CHECK LEVEL!
Wa r n i n g !
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which may
burn if it comes into contact with hot engine parts.
You can be seriously burned.

246 Malfunction and warning messages
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
COOLANT TEMP.
1 Observe the coolant temperature gauge. See page 90.
Check coolant level, see page 261.
This may indicate that the poly-V-belt has broken. Should this
c on diti on oc cur, the po ly-V- belt m ust be r ep lac ed befor e c ont inui ng
to operate the vehicle. Otherwise, the engine will overheat due to
an inoperative water pump which may result in damage to the
engine. Do not continue to drive the vehicle with this message
displayed. Doing so could result in serious engine damage that is
not covered by the Mercedes-Benz Limited Warranty.
During severe operating conditions and stop-and-go city
traf f ic, th e coolant temperature may rise close to th e red
marking.
The engine should not be operated with the coolant
temperature in the red zone. Doing so may cause
serious engine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Line 1 Line 2
COOLANT TEMP. VISIT WORKSHOP!
1
Wa r n i n g !
Driving when your engine is badly overheated can
cause some fluids which may have leaked into the
engine compartment to catch fire. You could be
seriously burned.Steam from an overheated engine can cause serious
burns and can occur just by opening the engine
hood. Stay away from the engine if you see or hear
steam coming from it.Turn off the engine, get out of the vehicle and do
not stand near the vehicle until it cools down.

257 Engine compartment
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index Hood
Wa r n i n g !
To help prevent personal injury, stay clear of
moving parts wh en t he hood is open and th e engine
is running. Be sure the hood is properly closed
before driving. When closing hood, use extreme
caution not to catch hands or fingers.The radiator fan may continue to run for
approximately 30 seconds or even restart after the
engine has been turned off. Stay clear from fan
blades.
If you see flames or smoke coming from the engine
compartment, or if the coolant temperature gauge
indicates that the engine is overheated, do not open
the hood. Move away from vehicle and do not open
the hood until the engine has cooled. If necessary,
call a fire department.The engine is equipped with a transistorized
ignition system. Because of the high voltage it is
dangerous to touch any components (ignition coils,
spark plug sockets, diagnostic socket) of the
ignition system
• with the engine running,
• while starting the engine,
• if ignition is “on” and the engine is turned
manually.

262 Engine compartment
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Adding coolant
If coolant has to be add ed, a 50/50 mix ture of water and
MB anticorrosion / antifreeze should be added.
The drain plugs for the cooling system are located on
the right side of the engine block and at the bottom of
the radiator.
Anticorrosion / antifreeze, see page 322.
Wa r n i n g !
In order to avoid possibly serious burns:
• Use extreme caution when opening the hood if
there are any signs of steam or coolant leaking
from the cooling system, or if the coolant
temperature gauge indicates that the coolant is
overheated.
• Do not remove pressure cap on coolant
reservoir if engine temperature is above 194°F
(90°C). Allow engine to cool down before
removing cap. The coolant reservoir contains
hot fluid and is under pressure.• Using a rag, slowly open cap approximately
1/2
turn to relieve excess pressure. If opened
immediately, scalding hot fluid and steam will
be blown out under pressure.
• Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which may
burn if it comes into contact with hot engine
parts.