Mercedes-Benz 2005 E -Class Wagon Operator's Manual page 305

Operation
Engine compartment
Warning!
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 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 approx-
1
imately / turn to relieve excess pres-
2
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.
304
G
1 Coolant 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 455).