255 Operation
Engine compartment
Coolant
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking coolant level,
the vehicle must be parked on level
ground
the coolant temperature must be be-
low 158°F (70°C)
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 398).
Warning!
G
In order to avoid potentially 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 158°F (70°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.
310 Practical hintsWhat to do if ...
During severe operating conditions, e.g.
stop-and-go traffic, the coolant tempera-
ture may rise close to 248°F (120°C).
Problem
Possible cause/consequence
Suggested solution
D
The red coolant temperature
warning lamp comes on while
the engine is running.
There is insufficient coolant in the reservoir.
Immediately add coolant to prevent en-
gine from overheating (
page 255).
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 driv-
ing to the nearest authorized
Mercedes-Benz Center.
Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.
D
The red coolant temperature
warning lamp comes on while
the engine is running and you
hear a warning sound.
The coolant temperature has exceeded
248°F (120°C).
Stop as soon as possible in a safe loca-
tion and allow the engine and coolant
to cool down.
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 which can occur just by open-
ing the engine hood. Stay away from the en-
gine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of
the vehicle and do not stand near the vehicle
until the engine has cooled down.
!
The engine should not be operated with the
coolant temperature above 248°F (120°C). Do-
ing so may cause serious engine damage which
is not covered by the Mercedes-Benz Limited
Warranty.
328 Practical hintsWhat to do if ...Left display
Right display
Possible cause/consequence
Possible solution
P
Gear Selector
Lever To P
You wish to start the engine and the
selector lever is not in park
positionP.
Move the selector lever to park positionP.
Shift To N
To Start
Move the selector lever to neutral
positionN.
SLR
ACL Malfunction
Service
Required
The locking system is
malfunctioning.
The transmission cooling system
is malfunctioning.
Have the system checked at an authorized
Mercedes-Benz Center immediately.
SRS
Restraint System
Malfunction
Service
Required
There is a malfunction in the supple-
mental restraint systems. The
air bags or Emergency Tensioning
Devices (ETDs) could deploy unex-
pectedly or fail to activate in an acci-
dent.
Drive with added caution and have the
system checked at an authorized
Mercedes-Benz Center immediately.
Warning!
G
In the event that a malfunction of the SRS is
indicated as outlined above, the SRS may
not be operational. For your safety, we
strongly recommend that you contact an
authorized Mercedes-Benz Center immedi-
ately to have the system checked; otherwise
the SRS may not be deployed when needed
in an accident, which could result in serious
or fatal injury, or it might deploy
unexpectedly and unnecessarily which
could result in an accident and/or injury to
you or to others.
340 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
B
Top Up
Coolant
See Oper. Manual
The coolant level is too low.
Add coolant (
page 255).
Comply with all warnings while doing so.
If you have to add coolant frequently, have the cooling
system checked by an authorized Mercedes-Benz Center
immediately.
•
The cooling fan for the coolant
is malfunctioning.
Observe the coolant temperature gauge in the instru-
ment cluster (
page 29).
If the coolant temperature is below 248°F (120°C), you
may continue driving to the nearest specialist workshop.
Avoid placing heavy loads on the engine (e.g. by driving
uphill) as well as stop-and-go traffic.
Have the fan replaced as soon as possible.
Warning!
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 could be seriously burned.
!
Do not ignore the low engine coolant level
warning. Extended driving with the message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz
Limited Warranty.
Do not drive without sufficient amount of coolant
in the cooling system. The engine will overheat
causing major engine damage.
344 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
±
Service
Required
Certain electronic systems are
unable to relay information to
the control system. The follow-
ing systems may have failed:
Coolant temperature gauge
Tachometer
Have the electronic systems checked by an authorized
Mercedes-Benz Center immediately.
Fuel System
Malfunction
Service
Required
The fuel cooling system is
malfunctioning.
Contact an authorized Mercedes-Benz Center
immediately.
:
Engine
Oil Pressure
Service
Required
There is no oil in the engine.
There is a danger of engine
damage.
Stop your vehicle immediately in a safe location.
Switch off the engine.
Do not drive any further.
Contact an authorized Mercedes-Benz Center
immediately.
!
The engine oil level warning should not be
ignored. Extended driving with the symbol
displayed could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.
394 Technical dataFuels, coolants, lubricants, etc.
Capacity
Fuels, coolants, lubricants, etc.
Cooling system
approx. 10.6 US qt (10.0 l)
MB 325.0 Anticorrosion/Antifreeze
Low temperature cooling system
Mercedes-Benz SLR McLaren Roadster
Mercedes-Benz SLR McLaren Roadster 722 S
approx. 5.3 US qt (5.0 l)
approx. 6.3 US qt (6.0 l)
MB 325.0 Anticorrosion/Antifreeze
MB 325.0 Anticorrosion/Antifreeze
Fuel tank
including a reserve of
25.6 US gal (97.0 l)
3.2 US gal (12.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)
Air conditioning system
R134a refrigerant and special PAG lubricant
oil (never R12)
Hydraulic system for soft top
0.143 US qt (0.135 l)
ARAL Vitamol ZHM
Windshield washer and headlamp cleaning
system
7.4 US qt (7 l)
MB Windshield Washer Concentrate
1
1Use MB Windshield Washer Concentrate “MB SummerFit” and water for temperatures above freezing or MB Windshield Washer Concentrate “MB SummerFit” and
commercially available premixed windshield washer solvent/antifreeze for temperatures below freezing. Follow suggested mixing ratios (page 401).
398 Technical dataFuels, coolants, lubricants, etc.In areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Contact an au-
thorized Mercedes-Benz Center or visit
www.mbusa.com (USA only) for a listing of
approved product(s). Follow directions on
product label.
Do not blend other fuel additives with fuel.
This only results in unnecessary cost and
may be harmful to engine operation.
Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which pro-
vides:
corrosion protection
freeze protection
boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -35°F (-37°C) and
corrosion protection.
If the antifreeze mixture is effective to
-35°F (-37°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).The coolant solution must be used year
round to provide the necessary corrosion
protection and increase in the boil-over
protection. Refer to Maintenance Booklet
for replacement interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable if
MB 325.0 Anticorrosion/Antifreeze solu-
tion or other Mercedes-Benz approved
products of equal specification are used to
renew the coolant concentration or bring it
back up to the proper level.
For information on other Mercedes-Benz
approved products of equal specification,
contact an authorized Mercedes-Benz
Center or visit www.mbusa.com
(USA only).
!
Damage or malfunction resulting from poor
fuel quality or from blending additional fuel
additives other than those tested and approved
by us for use on Mercedes-Benz vehicles are not
covered by the Mercedes-Benz Limited Warranty
or by any pre-owned or Extended Limited war-
ranties.
!
Add premixed coolant solution only. Adding
water and MB 325.0 Anticorrosion/Antifreeze
separately from each other, could cause engine
damage not covered by the Mercedes-Benz
Limited Warranty.
399 Technical data
Fuels, coolants, lubricants, etc.
To provide important corrosion protection,
the solution must be at least 50% anticor-
rosion/antifreeze (equivalent to freeze
protection to approximately
-35°F [-37°C]). If you use a solution that is
more than 55% anticorrosion/antifreeze
(freeze protection to approximately
-49°F [-45°C]), the engine temperature
will increase due to the lower heat transfer
capability of the solution. Therefore, do not
use more than this amount of
anticorrosion/antifreeze.If the coolant level is low, water and
MB 325.0 Anticorrosion/Antifreeze
should be used to bring it up to the proper
level (have cooling system checked for
signs of leakage). Please make sure the
mixture is in accordance with label instruc-
tions.
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality, con-
sult an authorized Mercedes-Benz Center.