Mercedes-Benz 2007 E 320 BLUETEC Operator's Manual page 387

Practical hints
What to do if ...
Problem
D
The red coolant temperature
warning lamp comes on when
the engine is running.
The red coolant temperature
warning lamp comes on while
driving and you hear a warning
sound.
Warning!
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.
386
Possible cause/consequence
There is insufficient coolant in the reservoir.
If this warning lamp comes on frequently,
there is a leak in the cooling system.
If the coolant level is correct, the electric ra-
diator fan may be broken.
The coolant temperature has exceeded
248°F (120°C).
G
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.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
Suggested solution
Immediately add coolant to prevent
engine from overheating
( page 330).
Have the cooling system checked.
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.
Stop as soon as possible in a safe lo-
cation and allow the engine and cool-
ant to cool down.