Page 231 of 376

231 Operation
Engine 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: is up to the upper
mark on the bracing rib of the coolant
expansion tank (translucent)
for warm coolant: is approx. 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 345).
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.
Page 254 of 376

254 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
D
The red coolant warning lamp
lights up when the engine is run-
ning.
There is insufficient coolant in the reservoir.
If this warning lamp lights up frequently,
there is a leak in the cooling system.
If the coolant level is correct, the electric ra-
diator fan may be broken.
Immediately add coolant to prevent
engine from overheating
(page 230).
Have the cooling system checked.
If the coolant temperature is below
257 °F (125 °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
lights up while driving and you
hear a warning sound.
The coolant temperature has exceeded
257 °F (125 °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 it
cools down.
Page 287 of 376
287 Practical hints
What to do if …
Left display
Right display
Possible cause
Possible solution
K
Visit workshop!
The retractable hardtop is mal-
functioning.
Have the retractable hardtop checked by an au-
thorized Mercedes-Benz Center.
Lock
hardtop
The roof is not properly locked.
Push or pull on the retractable hardtop switch
until the indicator lamp in the switch goes out
and the roof is completely open or closed
(page 159).
±
Display defective
Visit workshop!
Certain electronic systems are un-
able to relay information to the
control system. The following sys-
tems may have failed:
Coolant temperature gauge
Tachometer
Cruise control display
Have the electronic systems checked by an au-
thorized Mercedes-Benz Center (
page 256).
W
Washer fluid
Check level!
The fluid level has dropped to
about 1/3 of total reservoir ca-
pacity.
Add washer fluid (
page 233).
Page 347 of 376

347 Technical data
Fuels, coolants, lubricants, etc.
Windshield and headlamp washer system
Both the windshield and headlamp washer
systems are supplied from the windshield
washer fluid reservoir.
The windshield and headlamp washer fluid
reservoir has a capacity of approx.
7.4 US qt. (7 l).
Refill the reservoir with MB Windshield
Washer Concentrate and water (or con-
centrate and commercially available
premixed windshield washer
solvent / antifreeze, depending on am-
bient temperatures).Windshield and headlamp washer fluid
mixing ratio
For temperatures above freezing use
MB Windshield Washer Concentrate “S”
and water:
1 part “S” to 100 parts water
(40 ml “S” to 4 l water)
For temperatures below freezing use
MB Windshield Washer Concentrate “S”
and commercially available premixed
windshield washer solvent / antifreeze:
1 part “S” to 100 parts solvent
(40 ml “S” to 4 l solvent).
Warning!
G
Washer solvent/antifreeze is highly flamma-
ble. Do not spill washer solvent/antifreeze
on hot engine parts because it may ignite.
You could be seriously burned.