2004 MERCEDES-BENZ E320 engine overheat

81 Safety and Security
Driving safety systems
The SBC brake servo assistance switches
off automatically

approximately two minutes after you
turned the SmartKey in the starter
switch to position0 or removed the
SmartKey


approximately two minutes after you
pressed the KEYLESS-GO* start/stop
button to turn off the engine or power
supply and opened the driver’s door
(with driver’s door open, the starter
switch is set to position 0, same as
SmartKey removed from starter
switch)


approximately 20 seconds after you
locked the vehicle from outside
Note on driving with the SBC


Following extended periods of only mi-
nor loads to your brake system, you
should occasionally apply the brakes
when traveling at high speeds. This im-
proves the grip of the brake pads.


After driving on wet or snow-covered
roads, you should apply your brakes
firmly before parking your vehicle. This
produces heat which serves to dry the
brake disks and help prevent corro-
sion.


On long and steep grades, shift to a
lower gear (gear range1, 2, or 3) to
prevent the brakes from overheating
and to reduce brake wear.


After hard braking, it is advisable to
drive on for some time so that the air
stream will cool down the brakes fast-
er.


Only Mercedes-Benz approved compo-
nents (e.g. brake pads) should be in-
stalled on your vehicle. Brake pads not
approved by Mercedes-Benz may im-
pair the safety of your vehicle.
Warning!
G
Have brake pad replacement and other work
on the SBC brake system carried out by
qualified technicians only. Contact your
Mercedes-Benz Center for further informa-
tion. The SBC brake system must be deacti-
vated prior to working on the system. High
pressure is intermittently built up in the sys-
tem as part of its automatic self-test. In ad-
dition, the system is automatically activated
when the vehicle is unlocked by SmartKey,
when the driver or passenger door is
opened, when the starter switch is turned to
position
1, when the brake pedal is de-
pressed or when the parking brake is re-
leased. Failure to deactivate the system
prior to maintenance will cause brake pis-
tons to extend and brake fluid to leak, which
may result in injuries (contusions and acid
burns). Extended brake pistons may also
cause injury.
Warning!
G
Be very careful not to endanger other road
users when you apply the brakes.

127 Controls in detail
Instrument cluster
Coolant temperature gauge
During severe operating conditions, e. g.
stop-and-go traffic, the coolant tempera-
ture may rise close to 248°F (120°C).
The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Trip odometer
Make sure you are viewing the trip odome-
ter display (
page 129).

If it is not displayed, press the è or
ÿ repeatedly until the trip odome-
ter appears.

Press and hold the reset button on the
instrument cluster (
page 22) until
the trip odometer is reset.
Warning!
G


Driving when your engine is 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 hood. Stay away from
the engine if you see or hear steam com-
ing from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
iExcessive coolant temperature trigger
a warning in the multifunction display
(page 314).

268 OperationDriving instructionsPower assistance
Brakes
Warning!
G
The brake system requires electrical energy
for operation.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 312) and
warning messages in the instrument cluster
(
page 318) come on while driving. To
brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected braking effect. If necessary, apply
full pressure to the brake pedal. Brakes may
only be applied to the front wheels. Stop-
ping distance is increased! If there is a mal-
function in the SBC brake system, we
recommend that the vehicle be transported
with all wheels off the ground using flatbed
or appropriate wheel lift/dolly equipment. A
tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
up to 30 miles (50 km) and at a speed not to
exceed 30 mph (50 km/h). For more infor-
mation, refer to “Towing the vehicle”
(page 381). For more information see
SBC brake system (
page 79).
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter 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 ef-
fect. 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 effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.

269 Operation
Driving instructions
To help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
j e c t e d t o m o d e r a t e l o a d s , y o u s h o u l d o c c a -
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads. If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on, there is a malfunction in the
SBC brake system (
page 79) or 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 res-
ervoir.
Have the brake system inspected by quali-
fied technicians immediately. Contact your
authorized Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact your authorized
Mercedes-Benz Center.
Only install brake pads and brake fluid rec-
ommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so that the air stream will cool
down the brakes faster.
!Be very careful not to endanger other
road users when you apply the brakes.
Refer to the description of the Brake
Assist System (BAS) (
page 76).
Warning!
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.
Be certain to read and observe the warning
notices on brake pad replacement
(page 326).!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 pre-
vent overheating of the brakes and re-
duces brake pad wear.

275 Operation
Driving instructions
Control and operation of radio trans-mitter
COMAND, radio and telephone*Telephones and two-way radios
Radio transmitters, such as a portable tele-
phone or a citizens band unit should only
be used inside the vehicle if they are con-
nected to an antenna that is installed on
the outside of the vehicle.
Refer to the radio transmitter operation in-
structions regarding use of an external an-
tenna.
Catalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Service Booklet.
Warning!
G
Please do not forget that your primary re-
sponsibility is to drive the vehicle safely.
Only operate the COMAND (Cockpit Man-
agement and Data System), radio or tele-
phone
1 if road, weather and traffic
conditions permit.
Bear in mind that at a speed of just 30 mph
(approximately 50 km / h), your vehicle is
covering a distance of approximately
44 feet (approximately 13.5 m) every sec-
ond.
1Observe all legal requirements
Warning!
G
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system, pos-
sibly resulting in an accident and/or
personal injury.
!To prevent damage to the catalytic con-
verters, 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.

277 Operation
Driving instructions
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to approximately
248°F (120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G


Driving when your engine is badly over-
heated can cause some fluids, which
may have leaked into the engine com-
partment, to catch fire. You could be se-
riously 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 the
engine has cooled down.

282 OperationEngine compartment
Closing
Let the hood drop from a height of ap-
proximately 1 ft (30 cm).
The hood will lock audibly.

Check to make sure the hood is fully
closed.
If you can raise the hood at a point
above the headlamps, then it is not
properly closed. Open it again and let it
drop with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when

the vehicle is new


the vehicle is driven frequently at
higher engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature 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 the fire department.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition 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
Warning!
G
Be careful that you do not close the hood on
anyone.
iDo not use any special lubricant addi-
tives, as these may damage the drive
assemblies. Using special additives not
approved by Mercedes-Benz will
restrict your warranty entitlement.
More information on this subject is
available at any Mercedes-Benz
Center.

286 OperationEngine compartment
1Coolant expansion tank
Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.

Continue turning the cap to the left and
remove it.The coolant level is correct if the level:


for cold coolant: reaches the black
top part of the reservoir


for warm coolant: is approximately
0.6 in (1.5 cm) higher

Add coolant as required.

Replace and tighten cap.
More information on coolant can be found
in the “Technical data” section
(
page 405).
Warning!
G
In order to avoid any 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 indi-
cates 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 the cap approx-
imately
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.