Chrysler Pacifica. Manual — part 708

OPERATION

The oil pressure switch provides a ground for the

instrument cluster low oil pressure indicator light.
The switch receives oil pressure input from the
engine main oil gallery. When engine oil pressure is
greater than 27.5 Kpa (4 psi), the switch contacts
open, providing a open circuit to the low pressure
indicator light. For wiring circuits and diagnostic
information, (Refer to Appropriate Wiring/Diagnostic
Information).

REMOVAL

(1) Raise vehicle on hoist.
(2) Disconnect electrical connector from switch.
(3) Remove oil pressure switch (Fig. 142).

INSTALLATION

(1) Install oil pressure switch. Torque oil pressure

switch to 23 N·m (200 in. lbs.) (Fig. 142).

(2) Connect electrical connector to switch.
(3) Lower the vehicle.
(4) Start engine and check for leaks.
(5) Check engine oil level. Adjust as necessary.

OIL PUMP

DESCRIPTION

The oil pump is located in the timing chain cover.

It is driven by the crankshaft.

REMOVAL

The oil pump is contained within the timing chain

cover housing.

(1) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-

CATION/OIL PAN - REMOVAL)

(2) Remove the timing chain cover. (Refer to 9 -

ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)

(3) Disassemble oil pump from timing chain cover.

(Refer to 9 - ENGINE/LUBRICATION/OIL PUMP -
DISASSEMBLY)

(4) Clean and Inspect oil pump components. (Refer

to 9 - ENGINE/LUBRICATION/OIL PUMP - CLEAN-
ING) (Refer to 9 - ENGINE/LUBRICATION/OIL
PUMP - INSPECTION).

DISASSEMBLY

(1) Remove oil pump cover screws, and lift off

cover (Fig. 143).

(2) Remove oil pump rotors (Fig. 143).
(3) Clean and inspect oil pump components. (Refer

to 9 - ENGINE/LUBRICATION/OIL PUMP - CLEAN-
ING) (Refer to 9 - ENGINE/LUBRICATION/OIL
PUMP - INSPECTION).

Fig. 142 OIL FILTER ADAPTER

1 - SEAL
2 - OIL FILTER ADAPTER
3 - OIL FILTER
4 - BOLT
5 - OIL PRESSURE SWITCH
6 - BOLT

Fig. 143 OIL PUMP

1 - TIMING CHAIN COVER
2 - SCREWS
3 - INNER ROTOR
4 - OUTER ROTOR
5 - COVER

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ENGINE 3.8L

9 - 187

OIL PRESSURE SWITCH (Continued)

CLEANING

(1) Clean all parts thoroughly in a suitable sol-

vent.

INSPECTION

(1) Inspect mating surface of the chain case cover.

Surface should be smooth. Replace cover if scratched
or grooved.

(2) Lay a straightedge across the pump cover sur-

face (Fig. 144). If a 0.025 mm (0.001 in.) feeler gauge
can be inserted between cover and straight edge,
cover should be replaced.

(3) Measure thickness and diameter of outer rotor.

If outer rotor thickness measures 7.64 mm (0.301 in.)
or less (Fig. 145), or if the diameter is 79.95 mm
(3.148 in.) or less, replace outer rotor.

(4) If inner rotor thickness measures 7.64 mm

(0.301 in.) or less, replace inner rotor (Fig. 146).

(5) Install outer rotor into chain case cover. Press

rotor to one side with fingers and measure clearance
between rotor and chain case cover (Fig. 147). If mea-
surement is 0.39 mm (0.015 in.) or more, replace
chain case cover, only if outer rotor is in specification.

Fig. 144 Checking Oil Pump Cover Flatness

1 - FEELER GAUGE
2 - OIL PUMP COVER
3 - STRAIGHT EDGE

Fig. 145 Measuring Outer Rotor Thickness

Fig. 146 Measuring Inner Rotor Thickness

Fig. 147 Measuring Outer Rotor Clearance in

Housing

1 - FEELER GAUGE
2 - OUTER ROTOR

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ENGINE 3.8L

CS

OIL PUMP (Continued)

(6) Install inner rotor into chain case cover. If

clearance between inner and outer rotors (Fig. 148) is
0.203 mm (0.008 in.) or more, replace both rotors.

(7) Place a straightedge across the face of the

chain case cover, between bolt holes. If a feeler gauge
of 0.10 mm (0.004 in.) or more can be inserted
between rotors and the straightedge, replace pump
assembly (Fig. 149). ONLY if rotors are in specs.

(8) Remove oil pressure relief valve. (Refer to 9 -

ENGINE/LUBRICATION/OIL PRESSURE RELIEF
VALVE - REMOVAL)

(9) Inspect oil pressure relief valve and bore.

Inspect for scoring, pitting and free valve operation
in bore (Fig. 150). Small marks may be removed with
400-grit wet or dry sandpaper.

(10) The relief valve spring has a free length of

approximately 49.5 mm (1.95 inches) it should test
between 19.5 and 20.5 pounds when compressed to
34 mm (1-11/32 inches). Replace spring that fails to
meet specifications.

(11) If oil pressure is low and pump is within spec-

ifications, inspect for worn engine bearings or other
reasons for oil pressure loss.

ASSEMBLY

(1) Assemble pump, using new parts as required.

Install the inner rotor with chamfer facing the
cast iron oil pump cover.

(2) Prime oil pump before installation by filling

rotor cavity with engine oil.

(3) Install cover and tighten screws to 12 N·m (105

in. lbs.).

(4) If removed, install the oil pressure relief valve.

(Refer to 9 - ENGINE/LUBRICATION/OIL PRES-
SURE RELIEF VALVE - INSTALLATION).

INSTALLATION

(1) Install oil pump. (Refer to 9 - ENGINE/LUBRI-

CATION/OIL PUMP - ASSEMBLY)

(2) Install

timing

chain

cover

(Refer

to

9

-

ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION) and oil pan (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).

INTAKE MANIFOLD

DESCRIPTION

The intake system is made up of an upper and

lower intake manifold. The upper intake manifold is

Fig. 148 Measuring Clearance Between Rotors

1 - FEELER GAUGE
2 - INNER ROTOR
3 - OUTER ROTOR

Fig. 149 Measuring Clearance Over Rotors

1 - FEELER GAUGE
2 - STRAIGHT EDGE

Fig. 150 Oil Pressure Relief Valve

1 - RELIEF VALVE
2 - SPRING
3 - RETAINER CAP

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ENGINE 3.8L

9 - 189

OIL PUMP (Continued)

made of a composite material for the 3.8L engine.
The lower intake manifold also provides coolant
crossover between cylinder heads and houses the
coolant thermostat

The intake manifold utilizes a compact design with

very low restriction and outstanding flow balance.
This design allows the engine to perform with a wide
torque curve while increasing higher rpm horse-
power.

If, for some reason, the molded-in vacuum ports

break, the composite manifold can be salvaged. The
vacuum ports are designed to break at the shoulder,
if overloaded. Additional material in the shoulder
area provides sufficient stock to repair. For more
information and procedure, (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - STANDARD
PROCEDURE). Also, if the special screws that attach
the MAP sensor, power steering reservoir, throttle
cable bracket, and the EGR tube become stripped, an
oversized screw is available to repair the stripped-out
condition. For more information and procedure,
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - STANDARD PROCEDURE)

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

STANDARD PROCEDURE

STANDARD PROCEDURE - MANIFOLD
STRIPPED THREAD REPAIR

The

composite

upper

intake

manifold

thread

bosses, if stripped out, can be repaired by utilizing a
repair screw available through Mopar

t parts. Repair

screws are available for the following manifold
attached components:

• MAP sensor

• Power steering reservoir

• EGR tube

• Throttle cable bracket
The repair screws require a unique tightening

torque specification from the original screw. Refer to
the following chart for specification.

DESCRIPTION

TORQUE*

STRIP-OUT REPAIR SCREWS ONLY

MAP Sensor Repair
Screw

4 N·m (35 in. lbs.)

Power Steering Reservoir
Repair Screw

9 N·m (80 in. lbs.)

EGR Tube Attaching
Repair Screw

9 N·m (80 in. lbs.)

Throttle Cable Bracket
Repair Screw

9 N·m (80 in. lbs.)

*Install Slowly Using Hand Tools Only

STANDARD PROCEDURE - INTAKE MANIFOLD
VACUUM PORT REPAIR

The composite intake manifold vacuum ports can

be repaired. Although, if the manifold plenum cham-
ber is damaged or cracked, the manifold must be
replaced.

To repair a broken or damaged vacuum port on the

composite intake manifold, perform the following pro-
cedure:

PARTS REQUIRED

TOOLS REQUIRED

· Brass Port – 1/4

9

O.D. x

1/8

9

pipe thread

(LDP/Speed Control Port)

· Pipe Tap – 1/8

9

- 18

NPT

· Drill Bit – 11/32

9

· File/Sandpaper

· Brass Port – 1/2

9

O.D. x

1/4

9

pipe thread (Brake

Booster Port)

· Pipe Tap – 1/4

9

- 18

NPT

· Drill Bit – 7/16

9

· File/Sandpaper

NOTE: While performing this procedure, avoid get-
ting the manifold material residue into the plenum
chamber.

(1) File or sand the remaining port back until a

flat surface is obtained (plane normal to port axis).

(2) Drill out the port base using a 7/16” (brake

booster port) or 11/32” (LDP/speed control port ) drill
bit (Fig. 151).

(3) Using a 1/4”–18 NPT (brake booster port) or

1/8”–18 NPT (LDP/speed control port ) pipe tap, cut

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ENGINE 3.8L

CS

INTAKE MANIFOLD (Continued)