2005 MERCEDES-BENZ E320 engine overheat

361 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
D
The red coolant warning lamp
comes on when the engine is
running.
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.

Immediately add coolant to prevent
engine from overheating
(page 308).

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
comes on 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.
l
The red DTR warning lamp
comes on while driving.
You are too close to the vehicle in front of you
to maintain selected speed.

Apply the brakes immediately to in-
crease the following distance.
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 the
engine has cooled down.

378 Practical hintsWhat to do if …Symbol messagesDisplay symbol
Display messages
Possible cause
Possible solution
#
Undervoltage
Switch off
consumers
The battery has insufficient voltage.

Turn off unnecessary electrical con-
sumers.
Visit workshop
The battery is no longer charging.
Possible causes:

alternator malfunctioning


broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be oper-
ating with restricted capability.
Considerably greater brake pedal force is
required and the stopping distance is in-
creased.

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:

Drive immediately to the nearest au-
thorized Mercedes-Benz Center. Ad-
just driving to be consistent with
reduced braking responsiveness.

381 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
(USA only);(Canada only)3
Reduced braking power
Visit workshop
The SBC brake system is in emergency
operation mode. Considerable brake ped-
al force is required and the stopping dis-
tance is increased.

Continue driving with added caution.

Adjust driving to be consistent with
reduced braking responsiveness.

Visit an authorized Mercedes-Benz
Center as soon as possible.
Service brake
Visit workshop
There are malfunctions, but the SBC
brake system is operating normally.

Visit an authorized Mercedes-Benz
Center as soon as possible.
Brake overheated
Drive carefully
The brake system is overheated due to an
excessive load on the brakes.

Relieve the load on the brake system.

Drive more smoothly and think ahead
to avoid unnecessary braking.

When driving down slopes, shift into a
lower gear to use the engine’s braking
power (
page 176).

Cautiously continue driving so that
the air stream will cool down the
brakes.
Release
parking brake
You are driving with the parking brake
set.

Release the parking brake
(page 48).

383 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
?
(USA only)
±
(Canada only)
Visit workshop
There may be a malfunction in the:

fuel injection system


ignition system


exhaust system


fuel system

Have the measuring system checked
by an authorized Mercedes-Benz Cen-
ter.
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 308).

If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Center.
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 can 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 en-
gine damage.

384 Practical hintsWhat to do if …
During severe operation conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The coolant is too hot.

Stop the vehicle.

Only start the engine again after the
message disappears. You could other-
wise damage the engine.
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 the
engine has cooled down.
!The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
damage which is not covered by the
Mercedes-Benz Limited Warranty.

385 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The poly-V-belt could be broken.

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:

Do not continue to drive the vehicle
with this message displayed. Doing so
could result in serious engine damage
that is not covered by the
Mercedes-Benz Warranty.

Drive immediately to the nearest au-
thorized Mercedes-Benz Center.
Coolant
Visit workshop
The cooling fan for the coolant is malfunc-
tioning.

Observe the coolant temperature dis-
play.

Have the fan replaced as soon as pos-
sible.