engine overheat MERCEDES-BENZ S CLASS 2000 Owners Manual

117 Instrument cluster
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Coolant temperature gauge (5)
During severe operating conditions and stop-and-go city
traffic, the coolant temperature may rise close to the 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 (6)
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.
Note:
The temperature indicator display can be set to read out
in either Fahrenheit or Celsius. See page 138.
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.

224 Catalytic converter
Te ch n ica l
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.

244 Driving instructions
Te ch n ica l
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 fluid
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.
All checks and service work on the brake system should
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, the braking properties of the vehicle can be
degraded to an extent that safe braking is
substantially impaired. This could result in an
accident.

245 Driving instructions
Te ch n ica l
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.
When starting off on a slippery surface, do not allow 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.

305 Malfunction and warning messages
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index BATTERY / ALTERNATOR
* C = Category, see page 303
This 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 1Line 2C*
BATTERY/ALTERNATOR VISIT WORKSHOP! 2

310 Malfunction and warning messages
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
COOLANT (coolant level)
* C = Category, see page 303When 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.
Note:
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 117.
See page 336 for instructions on topping up the coolant.Line 1Line 2C*
COOLANT CHECK LEVEL! 2
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.

311 Malfunction and warning messages
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index COOLANT (coolant temperature)
* C = Category, see page 303
1 This 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.
2 The cooling fan for the coolant is faulty. Observe the coolant
temperature gauge. See page 117
During severe operating conditions and stop-and-go city
traffic, the coolant temperature may rise close to the 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 1Line 2C*
COOLANT STOP, ENGINE OFF!
1
1
COOLANT VISIT WORKSHOP!
2
2
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.

331 Engine compartment
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index Auxiliary fuse box below rear seat
4Auxiliary fuse box below right rear seat
To o pen :
Rem ove the cover.
To cl os e:
Press the cover on.Hood
4
P82.10-0911-26
Wa r n i n g !
To help prevent personal injury, stay clear of
moving parts when the hood is open and the 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.

336 Engine compartment
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Coolant level
1Coolant expansion tank
To check the coolant level, the vehicle must be parked
on level ground and the engine stopped.
Check coolant level only when coolant is cold.
The coolant level should reach the black top part of the
reservoir.
See page 398 for antifreeze / anticorrosion mixture.Adding coolant
If coolant has to be added, a 50/50 mixture of water and
MB anticorrosion / antifreeze should be added.
P82.35-2001-26
1
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.