Chrysler Town, Dodge Caravan. Manual - part 310

INTAKE MANIFOLD

DESCRIPTION

The intake manifold is a two piece aluminum cast-

ing (Fig. 101) that attaches to the cylinder head with
fasteners. The manifold is a long branch design to
enhance low and mid-range torque

DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS

An intake manifold air leak is characterized by

lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.

WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.

(1) Start the engine.
(2) Spray a small stream of water (Spray Bottle) at

the suspected leak area.

(3) If engine RPM’S change, the area of the sus-

pected leak has been found.

(4) Repair as required.

INTAKE MANIFOLD - UPPER

REMOVAL

(1) Disconnect negative cable from battery.
(2) Disconnect connector from inlet air tempera-

ture sensor (Fig. 102).

(3) Disconnect air intake tube at throttle body and

remove upper air cleaner housing.

(4) Disconnect connector from throttle position

sensor (TPS) (Fig. 104).

(5) Disconnect connector from idle air control (IAC)

motor (Fig. 104).

(6) Disconnect connector from MAP sensor (Fig. 103).

(7) Remove vacuum lines for purge solenoid and

PCV valve at intake manifold.

(8) Remove vacuum lines for power brake booster,

LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.

Fig. 101 Intake Manifold - Upper and Lower

1 - UPPER INTAKE MANIFOLD
2 - LOWER INTAKE MANIFOLD

Fig. 102 INLET AIR TEMPERATURE SENSOR - 2.4L

Fig. 103 MAP SENSOR - 2.4L

1 - MAP SENSOR

9 - 58

ENGINE 2.4L

(9) Disconnect

throttle

and

speed

control

(if

equipped) cables from throttle lever and bracket.
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE CONTROL CABLE - REMOVAL)

(10) Remove the EGR tube. (Refer to 25 - EMIS-

SIONS CONTROL/EXHAUST GAS RECIRCULA-
TION/TUBE - REMOVAL)

(11) Remove the upper manifold support bracket

bolt to manifold (Fig. 105).

(12) Remove engine oil dipstick from tube.
(13) Remove upper intake manifold bolts (Fig.

106). Remove upper intake manifold.

CAUTION: Cover intake manifold to prevent foreign
material from entering engine.

INSPECTION

(1) Check manifold surfaces for flatness with

straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.

(2) Inspect

manifold

for

cracks

distortion.

Replace manifold if necessary.

INSTALLATION

(1) Clean manifold sealing surfaces.
(2) Apply a 1.5 mm (0.060 in.) bead Mopar

t Gas-

ket Maker to the perimeter of the lower intake man-
ifold runner openings.

(3) Install upper intake manifold and tighten fas-

teners to 28 N·m (250 in. lbs.) in sequence shown in
(Fig. 106). Repeat this procedures until all fasteners
are at specified torque.

(4) Install engine oil dipstick.
(5) Install upper bolt in intake manifold to front

support bracket (Fig. 105). Torque to 28 N·m (250 in.
lbs.).

(6) Install EGR tube. (Refer to 25 - EMISSIONS

CONTROL/EXHAUST

GAS

RECIRCULATION/

TUBE - INSTALLATION)

(7) Install throttle cables in bracket.
(8) Connect throttle and speed control (if equipped)

cables to throttle lever.

(9) Connect vacuum lines for power brake booster,

LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.

(10) Connect vacuum lines for purge solenoid and

PCV valve.

(11) Connect electrical connectors for MAP sensor,

throttle position sensor (TPS), and idle air control
(IAC) motor.

(12) Install air cleaner upper housing and air

intake tube to throttle body.

(13) Connect inlet air temperature sensor connec-

tor (Fig. 102).

(14) Connect negative cable to battery.

Fig. 104 Throttle Body Electrical Connectors -

Typical

1 - IDLE AIR CONTROL MOTOR CONNECTOR
2 - TPS CONNECTOR

Fig. 105 Upper Intake Manifold Support Bracket

1 - NUT - BRACKET TO CYLINDER HEAD COVER
2 - BOLT - BRACKET TO UPPER INTAKE MANIFOLD
3 - UPPER INTAKE MANIFOLD SUPPORT BRACKET

Fig. 106 Upper Intake Manifold Tightening Sequence

- 2.4L

ENGINE 2.4L

9 - 59

INTAKE MANIFOLD - UPPER (Continued)

INTAKE MANIFOLD - LOWER

REMOVAL

(1)

Perform fuel system pressure release proce-

dure before attempting any repairs. (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE)

(2) Remove upper intake manifold. (Refer to 9 -

ENGINE/MANIFOLDS/INTAKE

MANIFOLD

REMOVAL)

CAUTION: Cover intake manifold openings to pre-
vent foreign material from entering engine.

(3) Disconnect fuel line. (Refer to 14 - FUEL SYS-

TEM/FUEL

DELIVERY/QUICK

CONNECT

FIT-

TING - STANDARD PROCEDURE)

(4) Drain the cooling system. (Refer to 7 - COOL-

ING - STANDARD PROCEDURE)

(5) Remove heater supply and radiator upper

hoses at intake manifold.

(6) Disconnect

coolant

temperature

sensor/fuel

injector wire harness connector.

(7) Remove lower intake manifold support bracket

upper bolts (Fig. 107).

(8) Loosen

the

lower

intake

manfold

support

bracket lower bolt (Fig. 107).

(9) Disconnect fuel injector harness.
(10) Remove the bolts attaching the power steering

reservoir to manifold. Set reservoir aside. Do not
disconnect line from reservoir.

(11) Remove lower intake manifold fasteners (Fig.

108). Remove the manifold from engine.

(12) Inspect the manifold. (Refer to 9 - ENGINE/

MANIFOLDS/INTAKE MANIFOLD - INSPECTION)

INSPECTION

(1) Check manifold surfaces for flatness with

straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.

(2) Inspect

manifold

for

cracks

distortion.

Replace manifold if necessary.

INSTALLATION

If the following items were removed, install and

torque to specifications:

• Fuel rail bolts - 22 N·m (200 in. lbs.)

• Coolant outlet connector bolts - 28 N·m (250 in.

lbs.)

• Coolant temperature sensor - 7 N·m (60 in. lbs.)
(1) Position a new gasket on cylinder head and

install lower manifold.

(2) Install and tighten intake manifold fasteners to

28 N·m (250 in. lbs.) in the sequence shown in (Fig.
108). Repeat procedure until all bolts are at specified
torque.

(3) Install lower intake manifold support bracket

bolts (Fig. 107) and tighten to:

• Bolts to intake 28 N·m (250 in. lbs.)

• Bolt to engine block 54 N·m (40 ft. lbs.)
(4) Position power steering reservoir on manifold

and install bolts.

(5) Connect the fuel line. (Refer to 14 - FUEL SYS-

TEM/FUEL

DELIVERY/QUICK

CONNECT

FIT-

TING - STANDARD PROCEDURE)

(6) Connect coolant temperature sensor/fuel injec-

tor wiring harness electrical connector.

(7) Install the radiator upper and heater supply

hoses.

(8) Install the upper intake manifold. (Refer to 9 -

ENGINE/MANIFOLDS/INTAKE

MANIFOLD

INSTALLATION)

(9) Fill the cooling system. (Refer to 7 - COOLING

- STANDARD PROCEDURE)

Fig. 107 Lower Intake Manifold Support Bracket

1 - SUPPORT BRACKET
2 - BOLTS - UPPER TO MANIFOLD
3 - BOLT - LOWER TO ENGINE BLOCK

Fig. 108 Lower Intake Manifold Tightening

Sequence

9 - 60

ENGINE 2.4L

EXHAUST MANIFOLD

REMOVAL

(1) Raise vehicle and disconnect exhaust pipe from

the exhaust manifold.

(2) Disconnect upstream oxygen sensor connector

at the rear of exhaust manifold.

(3) Remove the bolts attaching the manifold to the

cylinder head.

(4) Remove exhaust manifold.
(5) Inspect the manifold. (Refer to 9 - ENGINE/

MANIFOLDS/EXHAUST

MANIFOLD

INSPEC-

TION)

CLEANING

(1) Discard gasket (if equipped) and clean all sur-

faces of manifold and cylinder head.

INSPECTION

(1) Inspect manifold gasket surfaces for flatness

with straight edge. Surface must be flat within 0.15
mm per 300 mm (0.006 in. per foot) of manifold
length.

(2) Inspect manifolds for cracks or distortion.

Replace manifold as necessary.

INSTALLATION

(1) Install exhaust manifold with a new gasket.

Tighten attaching nuts in the sequence shown in
(Fig. 109) to 19 N·m (170 in. lbs.).

(2) Attach exhaust pipe to exhaust manifold and

tighten fasteners to 37 N·m (27 ft. lbs.).

(3) Install and connect the oxygen sensor. (Refer to

14 - FUEL SYSTEM/FUEL INJECTION/O2 SENSOR
- COMPONENT LOCATION)

TIMING BELT COVER(S)

REMOVAL

FRONT COVER - UPPER

(1) Remove upper timing belt cover fasteners (Fig.

110) and remove cover.

FRONT COVER - LOWER

(1) Remove crankshaft vibration damper (Refer to

ENGINE/ENGINE

BLOCK/VIBRATION

DAMPER - REMOVAL).

(2) Remove generator drive belt tensioner assem-

bly (Refer to 7 - COOLING/ACCESSORY DRIVE/
BELT TENSIONERS - REMOVAL).

(3) Remove timing belt front cover bolts (Fig. 110)

and remove covers.

REAR COVER

(1) Remove front covers.
(2) Remove engine mount bracket (Fig. 111).
(3) Remove timing belt (Refer to 9 - ENGINE/

VALVE TIMING/TIMING BELT AND SPROCKETS -
REMOVAL).

Fig. 109 Exhaust Manifold Tightening Sequence

Fig. 110 Front Timing Belt Covers

1 - BOLTS - UPPER FRONT COVER 6 N·m (50 in. lbs.)
2 - BOLTS - LOWER FRONT COVER 6 N·m (50 in. lbs.)

ENGINE 2.4L

9 - 61

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