Page 206 of 302
202 Check regularly and before a long trip
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Check regularly and before a long trip 1Coolant level
See “Adding coolant” on page 224.
2Windshield washer and
headlamp cleaning system
For refilling reservoir see page 226.
3Engine oil level
See “Checking engine oil level” on page 222 and 
“Engine oil level indicator” on page 82.
4Brake fluid
See “Brake fluid” on page 279.
Opening hood, see page 220.
Ve h i c l e  l i g h t i n g : Check function and cleanliness. For 
replacement of light bulbs, see “Exterior lamps” on page 
243.
Exterior lamp switch, see page 84. 
     
        
        Page 228 of 302
224 Coolant level
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hintsCar care Index
Coolant level
1Cap for coolant reservoirThe coolant level can be checked visually at the 
transparent coolant reservoir.
To check the coolant level, the vehicle must be parked 
on level ground.
Check coolant level only when coolant is cold:
The coolant should reach the rib in the filler neck. Also 
see marking (arrow) on reservoir. 
     
        
        Page 229 of 302

225 Coolant level
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hintsCar care Index Adding coolant
If coolant has to be added, a 50/50 mixture of water and 
MB anticorrosion/antifreeze should be added.
Model SL 500
The drain plugs for the cooling system are located on 
the right side of the engine block and at the bottom of 
the radiator. 
Model SL 600
The drain plugs for the cooling system are located on 
the right and left sides of the engine block and at the 
bottom of the radiator. 
Anticorrosion/antifreeze, see coolants on page 281. 
Wa r n i n g !
In order to avoid possible serious burns or injury:
• 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 engine 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.