2005 MERCEDES-BENZ SLR CLASS engine overheat

114 Controls in detailInstrument clusterCoolant temperature gaugeDuring 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.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 an can occur just by
opening the 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.
!Excessive coolant temperature triggers
the coolant temperature warning lamp
(page 300) and a warning in the
multifunction display (
page 320).

230 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 298) and
warning messages (
page 304) in the in-
strument cluster 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 are
only applied to the front wheels. Stopping
distance is increased! If there is a malfunc-
tion in the SBC brake system, we recom-
mend that the vehicle be transported with
all wheels off the ground using flatbed or ap-
propriate 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, see “Towing the vehicle”
(page 357).
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.

231 Operation
Driving instructions
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.
If the parking brake is released and the red
brake warning lamp in the instrument clus-
ter stays on, there is a malfunction in the
SBC brake system (
page 298) 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 immedi-
ately.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an 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
park the vehicle, so the air stream will cool
down the brakes faster.
iThe brake system is designed to decel-
er ate you r S LR f rom hi gh sp ee ds a t the
best possible rate. Depending on the
applied brake force, speed, and ambi-
ent conditions, the brake system may
produce a squeak-type noise when you
apply the brakes at a moderate rate. If
you experience this noise, you should
occasionally test the effectiveness of
the brakes by applying above-normal
braking pressure at high speeds. This
will also enhance the grip of the brake
pads.Warning!
G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
!Refer to the description of the Brake
Assist System (BAS) (
page 81).
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 85).!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.

237 Operation
Driving instructions
Control and operation of radio transmitters
Radio and telephoneTelephones and two-way radios
Radio transmitters, such as a portable
telephone or a citizens band unit should
only be used inside the vehicle if they are
connected to an antenna that is installed
on the outside of the vehicle.
Refer to the radio transmitter operation
instructions regarding use of an external
antenna.
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 Maintenance Booklet.
Warning!
G
Please do not forget that your primary
responsibility is to drive the vehicle safely.
Only operate the radio or telephone
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 44 feet
(approximately 14 m) every second.
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,
possibly resulting in an accident and
personal injury.
!To prevent damage to the catalytic
converters, only use 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 and potentially
start a fire.

239 Operation
Driving instructions
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant
temperature 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
engine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
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 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.

249 Operation
Engine compartment
Coolant
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Expansion tank

Using a rag, turn cap slowly approxi-
mately one half turn to the left to
release 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 upper
mark on the bracing rib of the ex-
pansion tank (arrow)


for warm coolant: is approximately
0.4 in (1 cm) higher

Add coolant as required.

Replace and tighten cap.
For more information, see “Coolants”
(
page 380).
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 coolant 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
approximately
1/2 turn to relieve excess
pressure. If opened immediately, scald-
ing 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.

300 Practical hintsWhat to do if ...Problem
Possible cause
Suggested solution
D
The red coolant warning lamp
comes on when the engine is
running.
There is insufficient coolant in the reservoir.

Immediately add coolant to prevent
engine from overheating
(page 249).
If this warning lamp comes on frequently,
there is a leak in the cooling system.

Have the cooling system checked by
an authorized Mercedes-Benz Center.
If the coolant level is correct, the electric
radiator fan may be broken.

If the coolant temperature is below
248°F (120°C), you can continue
driving to the nearest authorized
Mercedes-Benz Center.

Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.
D
The red coolant warning lamp
comes on while driving and you
hear a warning sound.
The coolant temperature has exceeded
248°F (120°C).

Stop as soon as possible and allow
the engine and coolant to cool down.
Warning!
G
Driving when your engine is badly overheat-
ed 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 the
engine has cooled down.

311 Practical hints
What to do if ...
Left display
Right display
Possible cause
Possible solution
#
Visit
workshop!
The battery is no longer charg-
ing. Possible causes:

alternator malfunctioning


broken poly-V-belt
Do not forget that the brake
system requires electrical ener-
gy and may be operating with
restricted capability. Consider-
ably greater brake pedal force
is required and the stopping
distance is increased.

Stop your vehicle safely immediately and check the
poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the engine will
overheat due to an inoperative water pump which
may result in damage to the engine. Notify an
authorized Mercedes-Benz Center.
If it is in order:

Drive immediately to the nearest authorized
Mercedes-Benz Center. Adjust driving to be consis-
tent with reduced braking responsiveness.

Observe the additional messages in the instrument
cluster.
There is a malfunction in the
electronic system.

Have the system checked at an authorized
Mercedes-Benz Center immediately.