2002 MERCEDES-BENZ ML320 engine overheat

245 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Seat belt warning lamp
With the key in steering lock position 2, the
seat belt warning lamp comes on for a short
time if the driver’s seat belt is not fastened.
After starting the engine, the warning lamp remains
illuminated for a short time to remind the driver and
passengers to fasten seat belts.
Charge indicator lamp
Should the charge indicator lamp fail to
come on prior to starting when the key is in
steering lock position 2 or should it fail to go
out after starting or during operation, this indicates a
malfunction which must be repaired at an authorized
Mercedes-Benz Light Truck Center immediately.If the charge indicator lamp comes on while the engine
is running, this may indicate that the poly-V-belt has
broken. Should this condition occur, the poly-V-belt
must be replaced before continuing to operate the
vehicle. Otherwise, the engine will overheat due to an
inoperative water pump which may result in damage to
the engine.
Do not continue to drive the vehicle with the charge
indicator lamp illuminated. Doing so could result in
serious engine damage that is not covered by the
Mercedes-Benz Limited Warranty.

246 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Low engine oil level warning lamp
With the key in steering lock position 2, the
oil level warning lamp comes on and should
go out when the engine is running.
If the warning lamp does not go out after starting the
engine, or comes on with the engine running and at
operating temperature, the engine oil level has dropped
to approximately the minimum mark on the dipstick.
When this occurs, the warning lamp will first come on
intermittently and then stay on if the oil level drops
further.
If no oil leaks are noted, continue to drive to the nearest
service station where the engine oil should be topped to
the “full” mark on the dipstick with an approved oil.
The low engine oil level warning light should not be
ignored. Extended driving with the light illuminated
could result in serious engine damage that is not
covered by the Mercedes-Benz Limited Warranty.
In addition to the warning lamp, the engine oil level
should be periodically checked with the dipstick or via
the oil level indicator in the odometer display field, for
example during a fuel stop, or before a long trip (see
engine oil level indicator on page 96 and checking
engine oil on page 255).Low engine coolant level warning
When the coolant level warning lamp comes
on while driving, then the coolant level has
dropped below the required level, or the
coolant temperature is in the red zone. If no leaks are
noticeable and the engine temperature does not
increase, continue to drive to the nearest service station
and have coolant added to the coolant system, see
page 256. If the engine temperature reaches the red
zone, move vehicle to an area which is in a safe distance
from the roadway and turn off the engine. Also see
coolant temperature gauge on page 87.
The low engine coolant level warning should not be
ignored. Extended driving with the symbol displayed
may cause serious engine damage not covered by the
Mercedes-Benz Limited Warranty.
In cases of major or frequent minor coolant loss, have
the cooling system checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.
Notes:
Do not drive without coolant in the cooling system. The
engine will overheat causing major engine damage.
Monitor the coolant temperature gauge while driving.

254 Engine compartment
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Wa r n i n g !
To help prevent personal injury, stay clear of
moving parts when the hood is open and the engine
is running. Be sure the hood is properly closed
before driving. When closing hood, use extreme
caution not to catch hands or fingers.The radiator fan may continue to run for
approximately 30 seconds or even restart after the
engine has been turned off. Stay clear from fan
blades.
The engine is equipped with a transistorized
ignition system. Because of the high voltage it is
dangerous to touch any components (ignition coils,
spark plug sockets, diagnostic socket) of the
ignition system
• with the engine running,
• while starting the engine,
• if ignition is “on” and the engine is turned
manually.If you see flames, steam or smoke coming from the
engine compartment, or if the coolant temperature
gauge indicates that the engine is overheated, do
not open the hood. Move away from vehicle and do
not open the hood until the engine has cooled. If
necessary, call a fire department.

257 Engine compartment
Te ch n i c a 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.
After adding coolant, close cap until you hear it click a
few times.
The drain plugs for the cooling system are located on
the left and right side of the engine block directly above
the engine mounts and at the bottom of the radiator.
Anticorrosion / antifreeze mixture, see page 319.
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 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 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.

273 Battery
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index If a tire constantly loses air, it should be inspected for
damage.
The spare tire should be checked periodically for
condition and inflation. Spare tire will age and become
worn over time even if never used, and thus should be
inspected and replaced when necessary.Battery
Important!
Battery replacement information:
The maintenance-free battery is located in the engine
compartment.
The service life of the battery is dependent on its
condition of charge. The battery should always be kept
sufficiently charged, in order to last an optimum length
of time.
Wa r n i n g !
Do not overinflate tires. Overinflating tires can
result in sudden deflation (blowout) because they
are more likely to become punctured or damaged
by road debris, potholes etc.. Follow recommended
inflation pressures.Do not overload the tires by exceeding the specified
vehicle capacity weight (as indicated by the label
on the driver’s door latch post). Overloading the
tires can overheat them, possibly causing a
blowout.
Wa r n i n g !
Failure to follow these instructions can result in
severe injury or death.Never lean over batteries while connecting, you
might get injured.Battery fluid contains sulfuric acid. Do not allow
this fluid to come in contact with eyes, skin or
clothing. In case it does, immediately flush affected
area with water and seek medical help if necessary.A battery will also produce hydrogen gas, which is
flammable and explosive. Keep flames or sparks
away from battery, avoid improper connection of
jumper cables, smoking etc..

325 Index
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car careIndex Driving instructions ...................................................... 192
Driving off ....................................................................... 194
Dust filter ......................................................................... 111
EEBP (Electronic brake proportioning) ........................ 222
Electrical outlet .............................................................. 252
Electronic brake proportioning (EBP) ........................ 222
Electronic stability program (ESP) .............................. 223
Control switch ...........................................................225
Malfunction indicator lamp ..................................... 243
Synchronizing ...........................................................224
Warning lamp ............................................................243
Electronic traction system (4-ETS+) ........................... 221
LOW RANGE – 4-ETS ...............................................222
Malfunction indicator lamp ..................................... 243
Emergency call
See Tele Aid ............................................................... 166
Emergency tensioning retractor (ETR) ......................... 57
Emergency unlocking in case of accident ................... 33
Emission control ............................................................ 179
Emission control label .................................................. 307
Engine compartment .....................................................253Engine malfunction
CHECK ENGINE
malfunction indicator lamp ............................... 240
Engine oil additives ....................................................... 316
Engine oil consumption ............................................... 256
Engine oil level
Checking .............................................................. 96, 255
Warning ..................................................................... 246
Engine oil level indicator ................................................ 96
Engine oils ...................................................................... 316
Capacities ................................................................... 314
Low engine oil level warning ................................. 246
Engine overheating ..........................................................87
Engine speed limit
Overrevving .................................................................. 88
Enlarged cargo area ....................................................... 149
Entrance lamps ............................................................... 130
ESP
LOW RANGE — ESP .................................................. 226
ESP (Electronic stability program) ............................. 223
Control switch .......................................................... 225
Malfunction indicator lamp .................................... 243
Synchronizing .......................................................... 224
Warning lamp ........................................................... 243
ETR (Emergency tensioning retractor) .........................57