CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 1) are designed
to create high flow combustion chambers to improve
performance, while minimizing the change to the
burn rate in the chamber. The cylinder head incorpo-
rates the combustion chamber. Two valves per-cylin-
der are used with inserted valve seats and guides. A
multi-layer steel (MLS) type gasket is used between
the cylinder head and engine block.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
Fig. 1 Cylinder Head and Components
1 - VALVE LOCKS 5 - SPRING SEATS
2 - RETAINERS 6 - CYLINDER HEAD
3 - VALVE SPRINGS 7 - VALVE - EXHAUST
4 - VALVE STEM SEALS 8 - VALVE - INTAKE
9s - 16 ENGINE 3.3/3.8L SUPPLEMENTRS
(11) Remove power steering fluid return hose with
cooler from vehicle.
INSTALLATION
INSTALLATION - 2.4L ENGINE
(1) Remove any used O-rings from ends of power
steering hose.
(2) Using a lint free towel, wipe clean hose ends,
power steering pump fitting and steering gear port.
(3) Install new O-ring on power steering gear end
of return hose. Lubricate O-ring using clean power
steering fluid.
CAUTION: Use care not to bend tube ends of the
power steering hoses when installing. Leaks and
restrictions may occur.
CAUTION: If a new return hose is being installed
and it does not have an insulating heat sleeve
installed, the heat shield from the original hose
must be transferred before hose installation.
(4) Route hose along rear of cradle crossmember
and start gear end of hose into gear port. Do not
tighten hose tube nut at this time.
(5) Attach hose to suspension cradle crossmember
using two routing clamps and bolts (Fig. 19). Tighten
clamp bolts to 23 N´m (200 in. lbs.) torque.
(6) Tighten return hose tube nut at power steering
gear port to 31 N´m (275 in. lbs.) torque.(7) Install the power steering fluid cooler on the
cradle crossmember reinforcement (Fig. 23). Install
the mounting bolts and tighten to 11 N´m (100 in.
lbs.).
CAUTION: Power steering fluid hoses must remain
away from the exhaust system and must not come
in contact with any unfriendly surfaces on the vehi-
cle.
(8) Route pump end of hose over cradle crossmem-
ber toward pump avoiding tight bends or kinking.
(9) Install return hose onto power steering pump
return fitting and secure with hose clamp (Fig. 19).
Tighten the screw-type clamp to a torque of 2 N´m
(18 in. lbs.).
CAUTION: To prevent overheating of power steering
fluid return hose, protective heat shield sleeve must
cover entire rubber hose.
(10) Slide insulating heat shield up over the clamp
on the return hose and tie-strap it in place.
(11) Install front emissions vapor canister. (Refer
to 25 - EMISSIONS CONTROL/EVAPORATIVE
EMISSIONS/VAPOR CANISTER - INSTALLATION)
(12) Lower vehicle.
(13) Fill and bleed the power steering system
using the Power Steering Pump Initial Operation
Procedure. (Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE)
(14) Inspect system for leaks.
INSTALLATION - 3.3L/3.8L ENGINE
(1) Remove any used O-rings from ends of power
steering hose.
(2) Using a lint free towel, wipe clean hose ends
and power steering gear hose port.
(3) Install a new O-ring on gear port end of power
steering fluid hose. Lubricate O-ring using clean
power steering fluid.
CAUTION: Use care not to bend tube ends of the
power steering hoses when installing. Leaks and
restrictions may occur.
CAUTION: Power steering fluid hoses must remain
away from the exhaust system and must not come
in contact with any unfriendly surfaces on the vehi-
cle.
(4) Route hose (with cooler attached) up toward
reservoir avoiding tight bends or kinking.
(5) Start steering gear end of hose into gear port.
Do not tighten hose tube nut at this time.
Fig. 23 POWER STEERING COOLER
1 - CRADLE CROSSMEMBER REINFORCEMENT
2 - POWER STEERING COOLER
RSPUMP19-49
HOSE - POWER STEERING RETURN (Continued)
(3) Select sensors.
(4) Read the transmission temperature value.
(5) Compare the fluid temperature value with the
fluid temperature chart (Fig. 210).
(6) Adjust transmission fluid level shown on the
indicator according to the chart.
(7) Check transmission for leaks.
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can
interfere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transaxle vent where it may be mistaken
for a leak.FLUID CONDITION
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
and is contaminated with metal or friction material
particles, a complete transaxle recondition is proba-
bly required. Be sure to examine the fluid on the dip-
stick closely. If there is any doubt about its condition,
drain out a sample for a double check.
MopartATF+4 (Automatic Transmission Fluid)
when new is red in color. The ATF is dyed red so it
can be identified from other fluids used in the vehicle
such as engine oil or antifreeze. The red color is not
permanent and is not an indicator of fluid condition.
As the vehicle is driven, the ATF will begin to look
darker in color and may eventually become brown.
This is normal.ATF+4 also has a unique odor that
may change with age. Consequently,odor and color
cannot be used to indicate the fluid condition
or the need for a fluid change.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
Fig. 210 Transmission Fluid Temperature Chart
1 - MAX. LEVEL
2 - MIN. LEVEL
21 - 202 41TE AUTOMATIC TRANSAXLERS
FLUID (Continued)
(3) Select sensors.
(4) Read the transmission temperature value.
(5) Compare the fluid temperature value with the
fluid temperature chart (Fig. 188). (6) Adjust transmission fluid level shown on the
indicator according to the chart. (7) Check transmission for leaks.
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly. Improper filling can also raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
which occur with a low fluid level. In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can
interfere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transaxle vent where it may be mistaken
for a leak.FLUID CONDITION
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
and is contaminated with metal or friction material
particles, a complete transaxle recondition is proba-
bly required. Be sure to examine the fluid on the dip-
stick closely. If there is any doubt about its condition,
drain out a sample for a double check. Mopar tATF+4 (Automatic Transmission Fluid)
when new is red in color. The ATF is dyed red so it
can be identified from other fluids used in the vehicle
such as engine oil or antifreeze. The red color is not
permanent and is not an indicator of fluid condition.
As the vehicle is driven, the ATF will begin to look
darker in color and may eventually become brown.
This is normal. ATF+4 also has a unique odor that
may change with age. Consequently, odor and color
cannot be used to indicate the fluid condition
or the need for a fluid change. After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
Fig. 188 Transmission Fluid Temperature Chart
1 - MAX. LEVEL 2 - MIN. LEVEL
RS
40TE AUTOMATIC TRANSAXLE21s - 103
FLUID (Continued)
Condition Possible Causes Correction
Normal pressures, but A/C
Performance Test air
temperatures at center panel
outlet are too high.1. Excessive refrigerant oil in
system.1. See Refrigerant Oil Level in this group.
Recover the refrigerant from the refrigerant
system and inspect the refrigerant oil content.
Restore the refrigerant oil to the proper level, if
required.
2. Blend door actuator
improperly installed or faulty.2. See Blend Door Actuator in this group. Inspect
the actuator for proper operation and replace, if
required.
3. Blend door inoperative or
sealing improperly.3. See HVAC Housing in this group. Inspect the
blend door for proper operation and sealing.
Repair if required.
The low side pressure is
normal or slightly low, and the
high side pressure is too low.1. Low refrigerant system
charge.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
2. Refrigerant flow through
the A/C evaporator is
restricted.2. See A/C Evaporator in this group. Replace the
restricted A/C evaporator, if required.
3. Faulty A/C compressor. 3. See A/C Compressor in this group. Replace
the compressor, if required.
The low side pressure is
normal or slightly high, and
the high side pressure is too
high.1. A/C condenser air flow
restricted.1. Check the A/C condenser for damaged fins,
foreign objects obstructing air flow through the
condenser fins, and missing or improperly
installed air seals. Clean, repair, or replace
components as required.
2. Refrigerant flow through
the receiver/drier is
restricted.2. See Receiver/Drier in this group. Replace the
restricted receiver/drier, if required.
3. Inoperative radiator
cooling fan.3. Test the radiator cooling fan and replace, if
required. Refer to Group 7.
4. Refrigerant system
overcharged.4. See Refrigerant System Charge in this group.
Recover the refrigerant from the refrigerant
system. Charge the refrigerant system to the
proper level, if required.
5. Air in the refrigerant
system.5. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
6. Engine overheating. 6. Test the engine cooling system and repair, if
required. Refer to Group 7.
The low side pressure is too
high, and the high side
pressure is too low.1. Accessory drive belt
slipping.1. Inspect the accessory drive belt condition and
tension. Tighten or replace the accessory drive
belt, if required. Refer to Group 7.
2. Faulty A/C expansion
valve.2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Faulty A/C compressor. 3. See A/C Compressor in this group. Replace
the compressor, if required.
RSHEATING & AIR CONDITIONING24-9
HEATING & AIR CONDITIONING (Continued)
(4) Install the two screws that secure the rear A/C
expansion valve to the evaporator tube sealing plate.
Tighten the screws to 11 N´m (97 in. lbs.).
(5) Install the rear evaporator line extension onto
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EVAPORA-
TOR - INSTALLATION - EVAPORATOR LINE
EXTENSION).
(6) Install the foam insulator wrap over the rear
expansion valve.
(7) Install the rear HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - INSTALLATION).
(8) Run the HVAC Cooldown Test to verify proper
operation.
HEATER CORE
DESCRIPTION
The rear heater core is located near the front of
the rear HVAC housing, behind the right rear wheel
house. It is a heat exchanger made of rows of tubes
and fins. One end of the core is fitted with a molded
plastic tank that includes integral heater core inlet
and outlet nipples. The rear heater core can be ser-
viced without removing the rear HVAC housing from
the vehicle.
OPERATION
Engine coolant is circulated through underbody
heater hoses to the rear heater core at all times. As
the coolant flows through the rear heater core, heat
removed from the engine is transferred to the heater
core fins and tubes. Air directed through the heater
core picks up the heat from the heater core fins. The
rear blend door allows control of the rear heater out-
put air temperature by controlling how much of the
air flowing through the rear HVAC housing is
directed through the heater core.
The rear heater core cannot be repaired and, if
faulty or damaged, it must be replaced.
STANDARD PROCEDURE - REAR HEATER
CORE FILLING
In its final installed position, the rear heater core
is positioned higher than the radiator fill cap. There-
fore, when the cooling system is drained and refilled,
gravity will not refill the heater core with coolant to
the proper level. This may result in two problems:1.
Insufficient coolant level in the engine cooling sys-
tem, which may result in engine overheating.2.Air
entrapped within the rear heater core, which may
result in insufficient rear heater performance. There
are two methods that may be employed to prevent
these problems:1.Pre-filling of the rear heater core.2.Thermal cycling of the engine cooling system. Fol-
lowing are descriptions of both prevention methods,
as well as a method to verify rear heater perfor-
mance.
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING
FRONT - WARNING - HEATER PLUMBING).
PRE-FILLING
If the rear heater core or the rear HVAC housing
have been removed from the vehicle for service, the
rear heater core may be pre-filled with the proper
engine coolant mixture prior to reconnecting the
heater hoses to the heater core hose fittings.
(1) The heater core should be installed in the rear
HVAC housing, and the rear HVAC housing should
be installed in the vehicle.
(2) Take the proper precautions to protect the car-
peting below the rear heater core from spilled engine
coolant and have absorbent toweling readily avail-
able to mop up any spills.
(3) Insert the small end of an appropriate funnel
into the upper hose fitting of the heater core (Fig. 4).
(4) Carefully pour the proper pre-mixed engine
coolant solution into the rear heater core through a
funnel until coolant begins to appear at the lower
hose fitting of the heater core.
(5) Use absorbent toweling to clean up any engine
coolant spills from the preceding operation.
(6) Reconnect the heater hoses to the rear heater
core (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - REAR/HEATER HOSE - INSTAL-
LATION).
Fig. 4 Pre-Filling Heater Core - Typical
1 - REAR HEATER CORE
RSPLUMBING - REAR24 - 101
A/C EXPANSION VALVE (Continued)