1999 MERCEDES-BENZ C-CLASS engine overheat

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 vehicl e 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 shou ld be repaired promptly. Otherwise, excessive
unburned fuel may reach the catalytic converter causing it to overheat, which could start a fire.



Warning!
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.

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Driving Instructions
Warning !
If you feel a sudden significant vibration or ride disturbance, or you suspect that possible damage
to your vehicle has occurred, you should turn on the hazard flashers, carefully slow down, and drive with

caution to an area which is a safe distance from the roadway.
Inspect the tires and under the vehicle for possible dama ge. If the vehicle or tires appear unsafe, have
it towed to the nearest Mercedes-Benz or tire dealer for repairs.


Power Assistance
Warning !
When the engine is not running, the brake and steering systems are without power assistance.
Under these circumstances, a much greater effo rt is necessary to stop or steer the vehicle.



Brakes
Warning !
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. 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 th ereby significantly reducing their effectiveness.
It may not be possible to stop the car in sufficient time to avoid an accident.


The condition of the parking brake system is checked eac h time the car is in the shop for the required 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 fluid in the reservoir.

Have the brake system inspected at an aut horized Mercedes-Benz dealer immediately.
All checks and maintenance work on the brake system s hould be carried out by an authorized Mercedes-Benz dealer.
Install only brake pads and brake fluid recommended by Mercedes-Benz.


Warning !
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.


Caution !
When driving down long and steep grades, relieve the load on the brakes by shifting into a lower gear. This helps prevent
overheating of the brakes and reduces brak e 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.



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Charge Indicator Lamp
Should the charge indicator lamp fail to come on prior to starting when the electronic key is in steering lock position 2
or should it fail to go out after starting or during operati on, this indicates a fault which must be repaired at an
authorized Mercedes-Benz dealer immediately.
If the charge indicator lamp comes on while the engine is ru nning, this may indicate that the poly-V-belt has broken.
Should this condition occur, the poly-V-bel t 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 the charge indicator lamp illuminated. Doing so could result in serious engine
damage that is not covered by the Mercedes-Benz Limited Warranty.

Low Engine Oil Level Warning Lamp
With the electronic key in steering lock position 2, the o il level warning lamp comes on. It should go out immediately
when the engine is running.
If the warning lamp does not go out after starting the engi ne, or comes on with the engine running and at operating
temperature, the engine oil level has dropped to approximately the minimum mark on the dipstick.
When this occurs, the warning lamp will first come on intermittently and then stay on if the oil level drops further.
If no oil leaks are noted, continue to drive to the nearest service station where the engine oil should be topped to the
"full" mark on the dipstick with an approved oil.
The low engine oil level warning light should not be ignored. Extended driving with the light illuminated could result in
serious engine damage that is not covered by the Mercedes -Benz Limited Warranty. In addition to the warning lamp,
the engine oil level should be periodically checked with the di pstick (or via the odometer display - Model 280 only), for
example during a fuel stop, or before a long trip (see Index)


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Outside Temperature Indicator
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.).
Adaptation 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.

Warning !
The outside temperature indicator is not designed to serve as an Ice-Warning Device and is therefore un-
suitable for that purpose. Indicated temperatures just above the freezing point do not guarantee that the road
surface is free of ice.


Coolant Temperature Gauge
If the antifreeze mixture is effective to -22°F (-30°C), the boiling point of the c oolant in the pressurized cooling system
of your vehicle is approx. 266°F (130°C). 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 wh ich is not covered by the Mercedes-Benz Limited
Warranty.

Warning !
• Driving when your engine is badly overheated can cause some fluids which may
have Beaked 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 car and do not stand near the car until it cools down.


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Low Engine Coolant Level Warning Lamp
With the electronic key in steering lock position 2, the warning lamp comes on.
It should go out when the engine is running. If the warning lamp does not go out after starting the
engine, or if it comes on while driving, then 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 (see Index).
The low engine coolant level warning light should not be ignored. Extended driving with the light
illuminated may cause serious engine damage not co vered by the Mercedes-Benz Limited Warranty.
In cases of major or frequent minor coolant lo ss, have the cooling system checked at your
authorized Mercedes-Benz dealer as soon as possible.

Note:
Do not drive without coolant in the cooling sy stem. The engine will overheat causing major engine
damage. Monitor the coolant temperature gauge while driving.

Warning !

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.


Low Windshield and Headlamp Washer System Fluid Level Warning Lamp
With the electronic key in steering lock position 2, the warning lamp comes on. It should go out when
the engine is running. If the warning lamp does not go out after starting the engine, or if it comes on
while driving, the level of the reservoir has droppe d to approx.1/4 of the total volume. The reservoir
should be refilled with MB Windshield Washer Concentrate "S" and water (or commercially available
premixed windshield washer solvent/antifreeze, depending on ambient temperature - see Index) at
the next opportunity. The reservoir for the windshie ld and headlamp washer systems is located in
the engine compartment.


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Hood





To open:
To unlock the hood, pull release lever (1) under the driver's
side of the instrument panel. At the same time handle
(2) will extend out of the radiator grill (it may be necessary to lift the hood up slightly).

Caution !
To avoid damage to the windshield wiper or hood, open the hood only with wiper in the parked position. Pull handle
(2) completely out of radiator grill and open hood (do not pull up on handle).

To close:
Lower hood and let it drop into lock from a height of approx. 1 ft. (30 cm), assisting with hands pl aced flat on edges
of hood (3). To avoid hood damage, if hood is not fully cl osed, repeat closing procedure. Do not push down on hood
to attempt to fully close it.

Warning!

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 engine is equipped with a transi storized 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.
If you see flames, steam or smoke coming from the engi ne 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.


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Example



Checking Coolant Level
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.


Adding Coolant
If coolant has to be added, a 50/50 mixture 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 Coolants in Index.


Warning!
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.


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