Concorde V6-2.7L VIN R (1998)
Coolant: Description and Operation
COOLANT
The cooling system is designed around the coolant. The coolant must accept heat from engine metal, in the cylinder head area near the exhaust valves
and engine block. Then carry this heat to the radiator where the tube/fin radiator can give it up to the air.
The use of aluminum cylinder blocks, cylinder heads, and water pumps requires special corrosion protection. Mopar Extended Life Coolant (orange in
color) or the equivalent ethylene glycol base coolant with corrosion inhibitors (called OAT, for Organic Additive Technology) is recommended for best
engine cooling without corrosion, when mixed only to a freeze point of -37° C (-35°F) to -59° C (-50° F). If it loses color or becomes contaminated,
drain, flush, and replace with fresh properly mixed solution.
The required ethylene-glycol (antifreeze) and water mixture depends upon the climate and vehicle operating conditions. The recommended mixture of
50/50 ethylene-glycol and water will provide protection against freezing to -37° C (-35° F). The antifreeze concentration must always be a minimum of
44%, year round, in all climates. If percentage is lower than 44%, engine parts may be eroded by cavitation, and cooling system components may
be severely damaged by corrosion. Maximum protection against freezing is provided with a 68% antifreeze concentration, which prevents freezing
down to -67.7° C (-90° F). A higher percentage will freeze at a warmer temperature. Also, a higher percentage of antifreeze can cause the engine to
overheat because the specific heat of antifreeze is lower than that of water.
100 Percent Ethylene-Glycol Should Not Be Used
Use of 100 Percent Ethylene-Glycol will cause formation of additive deposits in the system, as the corrosive inhibitive additives in ethylene-glycol
require the presence of water to dissolve. The deposits act as insulation, causing temperatures to rise as high as 149° C (300° F). this temperature
is hot enough to melt plastic and soften solder. The increased temperature can result in engine detonation. In addition, 100 % ethylene-glycol
freezes at 22° C (-8° F).
Propylene-Glycol Formulations Should Not Be Used
Propylene-glycol formulations do not meet the required specifications. It's overall effective temperature range is smaller than that of
ethylene-glycol. The freeze point of 50/50 propylene-glycol and water is -32° C (-26° F), 5 degrees higher than ethylene-glycol's freeze point. The
boiling point (protection against summer boil-over) of propylene-glycol is 125° C (257° F) at 96.5 kPa (14 PSI), compared to 128° C (263° F) for
ethylene-glycol. Use of propylene-glycol can result in boil-over and freeze up. Propylene-Glycol also has a poorer heat transfer characteristics than
ethylene-glycol. This can increase cylinder head temperatures under certain conditions.
Propylene-Glycol/Ethylene-Glycol Mixtures Should Not Be Used
Propylene-glycol/ethylene-glycol mixtures can cause the destabilization of various corrosion inhibitors, causing damage to the coling system
components. Also, once ethylene-glycol and propylene-glycol based coolants are mixed in the vehicle, conventional methods of determining the
freeze point will not be accurate. Both the refractive index and specific gravity differ between the ethylene-glycol and propylene-glycol.
CAUTION: Richer mixtures cannot be measured with field equipment and can lead to problems associated with 100 percent glycol. If there is doubt
that the coolant mixture is too rich for field equipment to measure, put a sample in a clean container. Add exactly the same amount of water and retest.
If the coolant in the vehicle is 100% antifreeze, the diluted sample will read 50%. If the coolant in the vehicle was 70% antifreeze and 30% water, the
diluted sample will read as 35%, etc.
SELECTION AND ADDITIVES
The use of aluminum cylinder blocks, cylinder heads, intake manifolds, and water pumps require special corrosion protection. Mopar Extended Life
Coolant (orange in color) or the equivalent is recommended for optimum engine cooling and protection against corrosion when mixed to a freeze point
of -37° C (-35° F) to -59° C (-50° F). If it looses color or becomes contaminated; drain, flush, and replace with fresh properly mixed solution.
WARNING: Antifreeze is an ethylene glycol base coolant and is harmful if swallowed or inhaled. If swallowed, drink two glasses of water and induce
vomiting. if inhaled, move to fresh air area. Seek medical attention immediately. 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. Dispose of glycol base coolant properly, contact your dealer or
government agency for location of collection center in your area. Do not open a cooling system when the engine is at operating temperature or hot under
pressure, personal injury can result. Avoid radiator cooling fan when engine compartment related service is performed, personal injury can result.
