2000 DODGE NEON Antifreeze

Coolant flow circuit for the 2.0L engine is shown in
(Fig. 1).
During any reassembly procedures all pipe fittings
in water jacket, and water box require cleaning and
application of thread sealant for entire length of
threads.
COOLANT
The cooling system is designed around the coolant.
The coolant must accept heat from engine block
metal and in the cylinder head area near the exhaust
valves. Then coolant carries this heat to the radiator
where the tube/fin assemblies can give off the heat to
the air.
MopartAntifreeze or the equivalent is recom-
mended for optimum cooling performance and corro-
sion protection when mixed to a freeze point of -37É C
(-35É F).
COOLANT REPLACEMENT
Refer to Group 0, Lubrication and Maintenance for
schedule.
COOLANT PERFORMANCE
Performance is measurable. For heat transfer pure
water excels (Formula = 1 btu per minute for eachdegree of temperature rise for each pound of water).
This formula is altered when necessary additives to
control boiling, freezing, and corrosion are added as
follows:
²Pure Water (1 btu) boils at 100ÉC (212ÉF) and
freezes at 0ÉC (32ÉF).
²100 Percent Glycol (.7 btu) can cause a hot
engine and detonation and will raise the freeze point
to 22ÉC (-8ÉF).
²50/50 Glycol and Water (0.82 btu) is the recom-
mended combination that provides a freeze point of
-37ÉC (-35ÉF). The radiator, water pump, engine
water jacket, radiator pressure cap, thermostat, tem-
perature gauge, sending unit and heater are all
designed for 50/50 glycol.
Where required, a 56 percent glycol and 44 percent
water mixture will provide a freeze point of -59ÉC
(-50ÉF).
CAUTION: Richer mixtures cannot be measured
with field equipment which can lead to problems
associated with 100 percent glycol.SELECTION AND ADDITIVES
The use of aluminum cylinder heads, intake mani-
folds, and water pumps requires special corrosion
Fig. 1 Cooling System Operation
1 ± HEATER
2 ± HEAT UP
3 ± COOL DOWN
4 ± PRESSURE CAP
5 ± THERMOSTAT HOUSING6 ± WATER PUMP
7 ± ENGINE
8 ± COOLANT RECOVERY SYSTEM TANK
9 ± RADIATOR
7 - 2 COOLING SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

protection. MopartAntifreeze or the equivalent is
recommended for best engine cooling without corro-
sion. When mixed only to a freeze point of -37ÉC
(-35ÉF) to -59ÉC (-50ÉF). If it looses color or becomes
contaminated, drain, flush, and replace with fresh
properly mixed solution.
COOLANT RECOVERY SYSTEM
This system works in conjunction with the radiator
pressure cap to utilize thermal expansion and con-
traction of the coolant to keep the coolant free of
trapped air. The system provides space for expansion
and contraction. Also, the system provides a conve-
nient and safe method for checking and adjusting the
coolant level at atmospheric pressure without remov-
ing the pressure cap. It also provides some reserve
coolant to compensate for minor leaks and evapora-
tion or boiling losses. All vehicles are equipped with
this system (Fig. 2).
Refer to Coolant Level Check, Deaeration, and
Pressure Cap sections for operation and service.
ENGINE THERMOSTAT
The engine thermostat is located on the front of
the engine (radiator side) in the thermostat housing/
engine outlet connector. The thermostat has an air
bleed (vent) located in the flange and a O-ring for
sealing incorporate on it. There is a relief in the ther-
mostat housing/outlet connector for the O-ring.
The engine thermostat is a wax pellet driven,
reverse poppet choke type. It is designed to provide
the fastest warm up possible by preventing leakage
through it and to guarantee a minimum engine oper-
ating temperature of 88 to 93ÉC (192 to 199ÉF). Also,
the thermostat will automatically reach wide open, to
accommodate unrestricted flow to the radiator astemperature of the coolant rises in hot weather to
around 104ÉC (220ÉF). Above this temperature the
coolant temperature is controlled by the radiator, fan,
and ambient temperatureÐnot the thermostat.
A thermostats primary purpose is to maintain
engine temperature in a range that will provide sat-
isfactory engine performance and emission levels
under all expected driving conditions. It also provides
hot water (coolant) for heater performance. It does
this by transferring heat from engine metal and
automatic transmission oil cooler (if equipped) to
coolant, moving this heated coolant to the heater core
and radiator, and then transferring this heat to the
ambient air.
RADIATOR
The radiator is a down-flow type (vertical tubes)
with design features that provide greater strength,
as well as sufficient heat transfer capabilities to keep
the engine coolant within operating temperatures.
The radiator functions as a heat exchanger, using
air flow across the exterior of the radiator tubes. This
heat is then transferred from the coolant and into
the passing air.
The radiator has an aluminum core with plastic
tanks. Although stronger than brass, plastic tanks
are subject to damage by impact. Always handle radi-
ator with care.
RADIATOR COOLING FAN MODULE
The radiator cooling fan is a single speed electric
motor driven fan. The fan module includes an electric
motor, fan blade, and a support shroud that is
attached to the radiator (Fig. 3).
Fig. 2 Coolant Recovery System
1 ± RECOVERY HOSE
2 ± ENGINE COOLANT RECOVERY CONTAINER
3 ± PRESSURE CAP
Fig. 3 Radiator Fan
1 ± SCREWS
2 ± LOWER MOUNTS
3 ± FAN MOTOR ELECTRICAL CONNECTOR
PLCOOLING SYSTEM 7 - 3
DESCRIPTION AND OPERATION (Continued)

COOLANTÐADDING ADDITIONAL
NOTE: The radiator cap should not be removed.
When additional coolant is needed, it should be
added to the coolant recovery/reserve container (Fig.17). Use only 50/50 concentration of ethylene glycol
type antifreeze and water
COOLANT LEVELÐSERVICING
NOTE: The cooling system is closed and designed
to maintain coolant level to the top of the radiator.
When servicing requires a coolant level check in
the radiator, the engine must beoffandnotunder
pressure. Drain several ounces of coolant from the
radiator drain cock while observing the Coolant
Recovery Container. Coolant level in the container
should drop slightly. Then remove the radiator cap,
(Fig. 17). The radiator should be full to the top. If
not, and the coolant level in the recovery container is
at the ADD mark there is a air leak in the recovery
system. Check hose or hose connections to the recov-
ery container, radiator filler neck or the pressure cap
seal to the radiator filler neck for leaks.
Fig. 17 Coolant Recovery Container and Pressure Cap Locations
1 ± ENGINE OIL FILL
2 ± ENGINE COOLANT RECOVERY CONTAINER3 ± ENGINE OIL DIPSTICK
4 ± COOLING SYSTEM PRESSURE CAP
Fig. 16 Coolant Level
1 ± COOLANT RECOVERY CONTAINER
7 - 18 COOLING SYSTEMPL
SERVICE PROCEDURES (Continued)

SAFETY PRECAUTIONS AND WARNINGS
WARNING: WEAR EYE PROTECTION WHEN SER-
VICING THE AIR CONDITIONING REFRIGERANT
SYSTEM. SERIOUS EYE INJURY CAN RESULT
FROM EYE CONTACT WITH REFRIGERANT. IF EYE
CONTACT IS MADE, SEEK MEDICAL ATTENTION
IMMEDIATELY.
DO NOT EXPOSE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC TYPE
LEAK DETECTOR IS RECOMMENDED.
LARGE AMOUNTS OF REFRIGERANT RELEASED
IN A CLOSED WORK AREA WILL DISPLACE THE
OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF REFRIGERANT AT
AVERAGE TEMPERATURE AND ALTITUDE IS
EXTREMELY HIGH. AS A RESULT, ANYTHING THAT
COMES IN CONTACT WITH THE REFRIGERANT
WILL FREEZE. ALWAYS PROTECT SKIN OR DELI-
CATE OBJECTS FROM DIRECT CONTACT WITH
REFRIGERANT. R-134a SERVICE EQUIPMENT OR
VEHICLE A/C SYSTEM SHOULD NOT BE PRES-
SURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR.
SOME MIXTURES OF AIR and R-134a HAVE BEEN
SHOWN TO BE COMBUSTIBLE AT ELEVATED
PRESSURES. THESE MIXTURES ARE POTENTIALLY
DANGEROUS AND MAY RESULT IN FIRE OR
EXPLOSION CAUSING INJURY OR PROPERTY
DAMAGE.
ANTIFREEZE IS AN ETHYLENE GLYCOL BASE
COOLANT AND IS HARMFUL IF SWALLOWED OR
INHALED. SEEK MEDICAL ATTENTION IMMEDI-
ATELY IF SWALLOWED OR INHALED. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN AND PETS.
DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE. PER-
SONAL INJURY CAN RESULT.
CAUTION: The engine cooling system is designed
to develop internal pressure of 97 to 123 kPa (14 to
18 psi). Allow the vehicle to cool a minimum of 15
minutes before opening the cooling system. Refer
to Group 7, Cooling System.
DESCRIPTION AND OPERATION
A/C REFRIGERANT LINES
DISCHARGE LINE
The discharge line is the line that goes from the
compressor to the condenser (Fig. 3). It has no ser-
viceable parts except the rubber O-rings. If the line
is found to be leaking or is damaged it must be
replaced as an assembly.
LIQUID LINE
The liquid line is the line that goes from the con-
denser to drier (Fig. 3). It has no serviceable parts
except the rubber O-rings. If the line is found to be
leaking or is damaged it must be replaced as an
assembly.
SUCTION LINE
The suction line is the large line that connects to
the expansion valve and goes to the compressor (Fig.
3). It also has a small line that goes to the filter/
drier. The suction line uses a gasket on the expan-
sion valve side and rubber O-rings on all other
connections.
There are no serviceable parts on the suction line
other than the rubber O-rings and expansion valve
gasket. If the line is found to be leaking or is dam-
aged it must be replaced as an assembly.
Fig. 3 A/C Compressor Lines
1 ± CONDENSER LIQUID LINE
2 ± SUCTION LINE
3 ± COMPRESSOR MANIFOLD SCREWS
4 ± COMPRESSOR
5 ± DISCHARGE LINE
24 - 4 HEATING AND AIR CONDITIONINGPL
GENERAL INFORMATION (Continued)