Engine Oil Pressure Sensor; Description; Operation; Oil Pump - Chrysler Vehicle User Manual

9 - 124 ENGINE 4.0L
ENGINE OIL PRESSURE
SENSOR

DESCRIPTION

The 3–wire, solid-state engine oil pressure sensor
(sending unit) is located in an engine oil pressure
gallery.

OPERATION

The oil pressure sensor uses three circuits. They
are:
• A 5–volt power supply from the Powertrain Con-
trol Module (PCM)
• A sensor ground through the PCM's sensor
return
• A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3–wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5–volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
instrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.

OIL PUMP

REMOVAL

A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Drain the engine oil.
(2) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(3) Remove the pump-to-cylinder block attaching
bolts. Remove the pump assembly with gasket (Fig.
88).
CAUTION: If the oil pump is not to be serviced, DO
NOT disturb position of oil inlet tube and strainer
assembly in pump body. If the tube is moved within
the pump body, a replacement tube and strainer
assembly must be installed to assure an airtight
seal.

INSTALLATION

A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
Fig. 88 Oil Pump Assembly
1 - OIL FILTER ADAPTOR
2 - BLOCK
3 - GASKET
4 - OIL INLET TUBE
5 - OIL PUMP
6 - STRAINER ASSEMBLY
7 - ATTACHING BOLTS
(1) Install the oil pump on the cylinder block using
a replacement gasket. Tighten the bolts to 23 N·m
(17 ft. lbs.) torque.
(2) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(3) Fill the oil pan with oil to the specified level.

VALVE TIMING

STANDARD PROCEDURE - VALVE TIMING

(1) Disconnect the spark plug wires and remove
the spark plugs.
(2) Remove the engine cylinder head cover .
(3) Remove the capscrews, bridge and pivot assem-
bly, and rocker arms from above the No.1 cylinder.
(4) Alternately loosen each capscrew, one turn at a
time, to avoid damaging the bridge.
(5) Rotate the crankshaft until the No.6 piston is
at top dead center (TDC) on the compression stroke.
(6) Rotate the crankshaft counterclockwise (viewed
from the front of the engine) 90°.
(7) Install a dial indicator on the end of the No.1
cylinder intake valve push rod. Use rubber tubing to
secure the indicator stem on the push rod.
(8) Set the dial indicator pointer at zero.
TJ