cooling MERCEDES-BENZ ML320 1997 Complete User Guide

296
Fuels, coolants, lubricants etc.
Te ch n ica l
data
Instruments
and controls Operation Driving
Instrument
cluster display Practical hints Car care Index
Gasoline additives
A major concern among engine manufacturers is carbon
build up caused by gasoline. Mercedes-Benz
recommends the use of only quality gasoline containing
additives that prevent the build up of carbon deposits.
After an extended period of using fuels without such
additives, carbon deposits can build up especially on the
intake valves and in the combustion area, leading to
engine performance problems such as:
• warm-up hesitation,
• unstable idle,
• knocking / pinging,
• misfire,
• power loss.
Do not blend other specific fuel additives with fuel.
They only result in unnecessary cost, and may be
harmful to the engine operation.
Damage or malfunctions resulting from poor fuel
quality or from blending specific fuel additives are not
covered by the Mercedes-Benz Limited Warranty. Coolants
The engine coolant is a mixture of water and
anticorrosion / antifreeze, which provides:
• corrosion protection,
• freeze protection,
• boiling protection (by increasing the boiling point).
The cooling system was filled at the factory with a
coolant providing freeze protection to approximately
-35 °F (-37 °C) and corrosion protection.
If the antifreeze mixture is effective to -22 °F (-30 °C), the
boiling point of the coolant in the pressurized cooling
system is reached at approx. 266 °F (130 °C).
The coolant solution must be used year round to provide
the necessary corrosion protection and increase in the
boil-over protection. You should have it replaced every
3years.
To provide the important corrosion protection, the
solution must be at least 45% anticorrosion / antifreeze
(equals a freeze protection to approx. - 22 °F [-30 °C]). If
you use a solution that is more than 55% anticorrosion/
antifreeze (freeze protection to approx. - 49 °F [-45 °C])-,

297
Fuels, coolants, lubricants etc.
Te ch n ica l
data
Instruments
and controls Operation Driving
Instrument
cluster display Practical hints Car care Index
the engine temperature will increase due to the lower
heat transfer capability of the solution. Therefore, do not
use more than this amount of anticorrosion / antifreeze.
If the coolant level is low, water and MB anticorrosion/
antifreeze should be used to bring it up to the proper
level (have cooling system checked for signs of leakage).
The water in the cooling system must meet minimum
requirements, which are usually satisfied by normal
drinking water. If your are not sure about the water
quality, consult your authorized Mercedes-Benz Light
Truck Center.
Anticorrosion/antifreeze
Your vehicle contains a number of aluminum parts. The
use of aluminum components in motor vehicle engines
necessitates that anticorrosion / antifreeze coolant used
in such engines be specifically formulated to protect the
aluminum parts. (Failure to use such anticorrosion/
antifreeze coolant will result in a significantly
shortened service life.)
Therefore the following product is strongly
recommended for use in your vehicle: Mercedes-Benz
Anticorrosion / antifreeze agent. Before the start of the winter season (or once a year in
the hot southern regions), you should have the
anticorrosion / antifreeze concentration checked. The
coolant is also regularly checked each time you bring
your vehicle to your authorized Mercedes-Benz Light
Truck Center for service.
Anticorrosion / antifreeze quantity
Approx. freeze protection
– 35 °F
(– 37 °C) – 49
°F
(– 45 °C)
6.4 US qt
(6.0 l) 7. 0 U S q t
(6.6 l)

52 Getting startedDrivingThe coolant temperature is over 248°F
(120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle as soon as possible
and turn off the engine. Allow engine
and coolant to cool.

Check the coolant level and add cool-
ant if necessary (
page 222).In case of accident
If the vehicle is leaking gasoline:

Do not start the engine under any cir-
cumstances.

Notify local fire and / or police authori-
ties.
If the extent of the damage cannot be de-
termined:

Notify an authorized Mercedes-Benz
Light Truck Center.
If no damage can be determined on the


major assemblies


fuel system


engine mount:

Start the engine in the usual manner.

135 Controls in detail
Automatic climate control
Automatic climate control panel in the front
Item
1
Thumbwheel for center air vent
2
Center air vent, adjustable
3
Defroster air vent windshield
4
Thumbwheels for side air vent
5
Side air vent, adjustable
6
Footwell air vent
7
Automatic climate control
Item
1
Air volume control
2
Defrosting
3
Air recirculation
4
Temperature control
5
Automatic control (temperature, air
distribution, air volume)
6
AC cooling on / off (AC
OFF
)
Residual heat / ventilation (REST)
7
Interior temperature sensor
8
Air distribution control
9
Rear window defroster
a
Rear passenger compartment venti-
lation on / off

136 Controls in detailAutomatic climate controlThe automatic climate control is operatio-
nal whenever the engine is running. You
can operate the climate control system in
either the automatic or manual mode. The
system cools or heats the interior depend-
ing on the selected interior temperature
and the current outside temperature.
Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.Warning!
G
When operating the automatic climate con-
trol, the air that enters the passenger com-
partment through the air vents in the
footwell can be very hot or very cold (de-
pending on the set temperature). This may
cause burns or frostbite on unprotected skin
in the immediate area of the air vents.
Always keep sufficient distance between un-
protected parts of the body and the footwell
air vents. If necessary, change the air flow
using the air distribution controls to direct
the air away from the footwell air vents
(page 138).
Warning!
G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air pollu-
tion) may require replacement of the fil-
ter before its scheduled interval. A
clogged filter will reduce the air volume
to the interior.
If the vehicle interior is hot, ventilate
the interior before driving off.
Keep the air intake grille in front of the
windshield free of snow and debris.
Do not touch the interior temperature
sensor to maintain a precise tempera-
ture.
The set value is indicated by a lighted
segment on the control wheels.

139 Controls in detail
Automatic climate control
Activating
Press buttonÄ (
page 135).
The indicator lamp on the button
comes on.
Deactivating

Press buttonÄ (
page 135).
The indicator lamp on the button goes
out.
Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the vehi-
cle will then no longer be cooled or dehu-
midified.

Press button° (
page 135).
The indicator lamp on the button°
comes on.
Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.

Press button° again.
The indicator lamp on the button°
goes out.
The air conditioning system uses the refrig-
erant R-134a. This refrigerant is free of
CFCs which are harmful to the ozone layer.
iTo achieve the fastest possible cooling
of the interior, the automatic climate
control automatically switches to air
recirculation. The indicator lamp in the
buttonÄ is not illuminated when
the system automatically switches to
air recirculation.
iThe air recirculation mode is
deactivated automatically

after 30 minutes if the automatic
climate control is switched on


after five minutes if the air condi-
tioning is switched off


after five minutes if the outside
temperature is above approximate-
ly 45°F (7 °C)
iCondensation may drip out from under-
neath the vehicle. This is normal and
not an indication of a malfunction.

141 Controls in detail
Automatic climate control
Rear passenger compartment ventila-tion and rear automatic climate control
Deactivating
For an improved cooling or heating output
in the front passenger compartment, you
can switch off the rear passenger compart-
ment ventilation.
Press button§ (
page 135).
The indicator lamp on the button
comes on.
The operation of the rear automatic
climate control and the fresh air supply
to the rear compartment is shut off.
Activating

Press button§ again.
The indicator lamp on the button goes
out.
The rear automatic climate control
switches to automatic mode and fresh
air enters the rear compartment.Automatic mode
The automatic climate control panel for the
rear is located on the rear center console.
1Air volume control
2Air distribution control
3Automatic control (air distribution, air
volume)

Press buttonU.
The indicator lamp on the button
comes on.
The automatic climate control cools or
heats the interior depending on the
temperature selected on the front
climate control unit.Adjusting air volume and air distribu-
tion manually
Adjusting air volume

Press upper part of buttonR.
The blower setting is increased each
time the button is pressed.

Press lower part of buttonR.
The blower setting is decreased each
time the button is pressed.iWhen the air volume or air distribution
control is pressed, the automatic mode
is switched off. The indicator lamp in
buttonU is turned off. Temperature
setting remains in automatic mode.


222 OperationEngine compartment
Screw filler cap2 back on filler neck.
More information on engine oil can be
found in the “Technical data” section
(
page 300) and (
page 301).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Light
Truck Center check the automatic trans-
mission.Coolant
The engine coolant is a mixture of water
and anticorrosion / antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!Excess oil must be siphoned or drained
off. It could cause damage to the
engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
Warning!
G
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 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 the cap approx-
imately ½ turn to relieve excess pres-
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.


249 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
/
The yellow coolant warning lamp
comes on when the engine is
running.
The coolant is to hot.
The coolant level is too low.

Stop as soon as possible and allow
the engine and coolant to cool down.

Check the coolant level and add
coolant if necessary (
page 222).
If the warning lamp comes on frequently,
there is a leak in the cooling system.

Have the cooling system checked by
an authorized Mercedes-Benz Light
Truck Center.
The coolant temperature gauge is above
248 °F (120 °C).
The coolant level is too low.

Stop as soon as possible and allow
the engine and coolant to cool down.

Add coolant to prevent engine from
overheating (
page 222).
If the coolant level is correct, the electrical
radiator fan may be broken.

If the coolant temperature is below
the red zone, drive on to the nearest
authorized Mercedes-Benz Light
Truck Center.
Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.

301 Technical data
Fuels, coolants, lubricants etc.
Model
Capacity
Fuels, coolants, lubricants etc.
Cooling system
approx. 12.7 US qt (12.0 l)
MB Anticorrosion / Antifreeze
Fuel tank
ML 350, ML 500
22.0 US gal (83.0 l)
Premium unleaded gasoline:
Posted Octane 91 (Avg. of 96 RON / 86 MON
including a reserve of
approx. 3.2 US gal (12.0 l)
Air conditioning system
R-134a refrigerant and special PAG lubricant
oil (never R-12)
Windshield washer and
headlamp cleaning
system*
8.0 US qt (7.6 l)
MB Windshield Washer Concentrate
1
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing or MB Windshield Washer Concentrate “S” and commercially available pre-
mixed windshield washer solvent / antifreeze for temperatures below freezing. Follow suggested mixing ratios (page 307).