Page 220 of 1938

DESCRIPTION AND OPERATION
WATER PIPESÐ3.0L ENGINE
The 3.0L engine uses metal piping beyond the
lower radiator hose to route (suction) coolant to the
water pump, which is located in the V of the cylinder
banks (Fig. 10).
These pipes are provided with inlet nipples for
thermostat bypass and heater return coolant hoses,
and brackets for rigid engine attachment. The pipes
employ O-rings for sealing at their interconnection
and to the water pump (Fig. 10).
COOLANT PERFORMANCE
Performance is measurable. For heat transfer pure
water excels (Formula = 1 btu per minute for each
degree 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 lower the freeze point
to -22ÉC (-8ÉF).
²50/50 Glycol and Water (.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.CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended.
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. This can lead to problems
associated with 100 percent glycol.
RADIATOR HOSES AND CLAMPS
WARNING: IF VEHICLE HAS BEEN RUN
RECENTLY, WAIT 15 MINUTES BEFORE WORKING
ON VEHICLE. RELIEVE PRESSURE BY PLACING A
SHOP TOWEL OVER THE CAP AND WITHOUT
PUSHING DOWN ROTATE IT COUNTERCLOCKWISE
TO THE FIRST STOP. ALLOW FLUIDS AND STEAM
TO ESCAPE THROUGH THE OVERFLOW TUBE.
THIS WILL RELIEVE SYSTEM PRESSURE
The hoses are removed by using constant tension
clamp pliers to compress the hose clamp.
A hardened, cracked, swollen or restricted hose
should be replaced. Do not damage radiator inlet and
outlet when loosening hoses.
Radiator hoses should be routed without any kinks
and indexed as designed. The use of molded hoses is
recommended.
Spring type hose clamps are used in all applica-
tions. If replacement is necessary replace with the
original MOPARtequipment spring type clamp.
WATER PUMPÐ2.4L ENGINE
The water pump has a diecast aluminum body and
housing with a stamped steel impeller. The water
pump bolts directly to the block. Cylinder block to
water pump sealing is provided by a rubber O-ring.
The water pump is driven by the timing belt. Refer
to Timing Belt in Group 9, Engine for component
removal providing access to water pump.
WATER PUMPÐ3.0L ENGINE
The pump bolts directly to the engine block, using
a gasket for pump to block sealing (Fig. 11). The
pump is serviced as a unit.
The water pump is driven by the timing belt. See
Timing Belt in Group 9, Engine for component
removal providing access to water pump.
Fig. 10 Engine Inlet Coolant Pipes 3.0L Engine
7 - 6 COOLING SYSTEMNS
Page 221 of 1938

WATER PUMPÐ3.3/3.8L ENGINES
The pump has a die cast aluminum body and a
stamped steel impeller. It bolts directly to the chain
case cover, using an O-ring for sealing. It is driven by
the back surface of the Poly-V Drive Belt.
DIAGNOSIS AND TESTING
Fig. 11 Water PumpÐ3.0L Engine
ACCESSORY DRIVE BELT
CONDITION POSSIBLE CAUSES CORRECTIONS
INSUFFICIENT ACCESSORY
OUTPUT DUE TO BELT SLIPPAGE1. Belt too loose 1. Adjust belt tension (4 cyl. engine).
Replace belt (6 cyl. engine)
2. Belt excessively glazed or worn 2. Replace and tighten as specified
BELT SQUEAL WHEN
ACCELERATING ENGINE1. Belts too loose 1. Adjust belt tension (4 cyl. engine).
Replace belt (6 cyl. engine)
2. Belt glazed 2. Replace belts
BELT SQUEAK AT IDLE1. Belts too loose 1. Adjust belt tension (4 cyl. engine).
Replace belt (6 cyl. engine)
2. Dirt or paint imbedded in belt 2. Replace belt
3. Non-uniform belt 3. Replace belt
4. Misaligned pulleys 4. Align accessories
5. Non-uniform groove or eccentric
pulley5. Replace pulley
BELT ROLLED OVER IN GROOVE
OR BELT JUMPS OFF1. Broken cord in belt 1. Replace belt
2. Belt too loose, or too tight 2. Adjust belt tension (4 cyl. engine).
Replace belt (6 cyl. engine)
3. Misaligned pulleys 3. Align accessories
4. Non-uniform groove or eccentric
pulley4. Replace pulley
NSCOOLING SYSTEM 7 - 7
DESCRIPTION AND OPERATION (Continued)
Page 222 of 1938
COOLING SYSTEM DIAGNOSIS
7 - 8 COOLING SYSTEMNS
DIAGNOSIS AND TESTING (Continued)
Page 223 of 1938
NSCOOLING SYSTEM 7 - 9
DIAGNOSIS AND TESTING (Continued)
Page 224 of 1938
7 - 10 COOLING SYSTEMNS
DIAGNOSIS AND TESTING (Continued)
Page 225 of 1938
NSCOOLING SYSTEM 7 - 11
DIAGNOSIS AND TESTING (Continued)
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7 - 12 COOLING SYSTEMNS
DIAGNOSIS AND TESTING (Continued)
Page 227 of 1938

CONDITION - AND CHECKS DIAGNOSIS
Inadequate Air Conditioning Performance - Cooling System Suspected
(1) Check for plugged air side of condenser and
radiator front and rear.(1) Wash out with low-velocity water.
(2) Assure fan runs whenever A/C head pressure
exceeds 1724 kPa (250 psi).(2) Repair as necessary.
(3) Check for missing air seals-recirculating air path.
(4) Assure correct cooling system parts.
Battery Dead - Suspect Fan Current Draw as Cause
(1) With a good, fully charged battery. (1) a - Assure fan control is operating properly.
(1) b - See charging system in Electrical, Group 8B.
Hot Smell - Suspect Cooling System
(1) Was temperature gauge high? (1) a - Yes, See9Gauge Reads High9
(1) b - No. See 2, 3, 4, and 5.
(2) Heat shields all in place? (2) a - Yes, See 3, 4, and 5.
(2) b - Repair or replace heat shields.
(3) Fan control operating properly? (3) a - Yes, See 4 and 5.
(3) b - No, See Radiator Fan Control this section.
(4) Heat exchanger air side plugged? (4) Clean as required.
(5) Engine missing or running rich? (5) Repair as required.
Poor Driveability - Suspect Failed Open Thermostat.
(1) Check diagnostics - is code 17 set? (Engine too
cold for too long)(1) If yes, change thermostat.
Poor Heater Performance - Suspect Failed Open Thermostat
(1) Does gauge read low? (1) See 3
(2) Check coolant level. (2) See 3
(3) Check diagnostics - is code 17 set? (Engine too
cold for too long)(3) If yes, change thermostat. If no, check heater
bypass valve, which should be closed except in Max
A/C or off mode; if not, see Heater and Air Conditioning
Group, 24.
Steaming, Observe Water Vapor Through Grill or Head Gap at Standstill at Idle - In Wet Weather
(1) This is normal. It is moisture, snow, or water on the
outside of the radiator that evaporates when the
thermostat opens to put hot coolant into the radiator.
This usually occurs in cold weather with no fan or air
flow to blow it away.(1) Normal condition - no service required.
NSCOOLING SYSTEM 7 - 13
DIAGNOSIS AND TESTING (Continued)