1995 JEEP YJ oil pressure

MALFUNCTION INDICATOR (CHECK ENGINE)
LAMP
The Powertrain Control Module (PCM) provides
ground for the malfunction indicator (Check Engine)
lamp on circuit G3. Circuit G3 connects to cavity 32
of the PCM. Circuit G5 connects to the instrument
cluster and supplies battery voltage for the malfunc-
tion indicator lamp. When illuminated, the malfunc-
tion indicator lamp displays the message CHECK
ENGINE.
For information regarding diagnostic trouble code
access using the malfunction indicator lamp, refer to
Group 14, Fuel Systems.
UP-SHIFT LAMP
On vehicles equipped with a manual transmission,
the Powertrain Control Module (PCM) provides
ground for the Up-Shift lamp on circuit K54. Circuit
G5 provides battery voltage for the lamp.
ABS WARNING LAMP
Circuit G5 provides power for the ABS warning
lamp at the instrument cluster. Ground for the ABS
warning lamp is provided by either the ABS control
module or by the ABS power relay when the relay is
not energized. The ABS control module illuminates
the lamp by providing ground on circuit G19.
Circuit G19 splices to connect to circuit B15
through a diode. When the ABS power relay is not
energized, it connects circuit B15 to circuit Z12. The
ground path for the warning lamp is provided
through the diode to circuit B15, through the ABS
power relay to ground on circuit Z12.
The diode between circuit G19 and B15 prevents
voltage from flowing to the ABS control module when
the ABS power relay switches to supply power on cir-
cuit B15.
BRAKE WARNING LAMP
Circuit G5 provides battery voltage for the brake
warning lamp. Circuit G11 can provide ground for
the lamp in 3 ways. The first ground path is through
the ignition switch when the key is in the START po-
sition.
The second ground path for the brake warning
lamp on circuit G11 is through the case grounded
brake warning switch. When the switch closes it pro-
vides a ground.
The third ground path on circuit G11 is through
the case grounded park brake switch. When the
switch closes it provides ground.
HIGH BEAM INDICATOR LAMP
Circuit G34 supplies power for the high-beam indi-
cator lamp when the operator either flashes the opti-
cal horn (high beams) or selects high beam operation.
Circuit Z1 provides the ground path for the lamp.
Circuit L3 from the headlamp switch powers the
high beam circuits of the headlamps. On vehicles not
equipped with Daytime Running Lamps (DRL), cir-
cuit G34 double crimps to circuit L3 at the bulkhead
connector.
On vehicles equipped with DRL, circuit L3 splices
to the DRL module. The DRL module powers circuit
G34.
TURN SIGNAL INDICATOR LAMPS
Circuit L61 supplies battery voltage to the left turn
signal indicator lamp. The right turn signal indicator
lamp receives battery voltage from circuit L60. The
turn signal/hazard flasher switch powers circuits L60
and L61. Circuit Z1 provides ground for the lamps.
HELPFUL INFORMATION
²If the warning lamps, gauges and indicator lamps
don't operate, check fuse 4 in the PDC and fuse 9 in
the fuse block.
²If the illumination lamps don't operate, check fuse
10 in the fuse block.
DIAGRAM INDEX
Component Page
4WD Switch............................8W-40-9
ABS Control Module......................8W-40-5
Brake Warning Switch.....................8W-40-5
Combination Buzzer.....................8W-40-7, 8
Daytime Running Lamp (DRL) Module.........8W-40-4, 6
Engine Coolant Temperature Sensor...........8W-40-7, 8
Engine Oil Pressure Sensor..................8W-40-9
Fuse 3 (PDC).......................8W-40-3, 7, 8
Fuse 4 (PDC).......................8W-40-4, 7, 8
Fuse 7 (PDC)...........................8W-40-6
Fuse 8 (Fuse Block)...................8W-40-3, 7, 8
Fuse 9 (Fuse Block).......................8W-40-8
Fuse 10 (Fuse Block).................8W-40-3, 7, 10
Gauge Package......................8W-40-7, 8, 9
Headlamp Switch...................8W-40-3, 6, 7, 8
Headlamp Dimmer Switch...................8W-40-6
Ignition Switch......................8W-40-4, 5, 8
Instrument Cluster...................8W-40-3 thru 9
Panel Lamp Dimmer Switch..............8W-40-3, 7, 8
Park Brake Switch........................8W-40-5
Powertrain Control Module.................8W-40-4, 5
8W - 40 - 2 8W-40 INSTRUMENT CLUSTERÐYJ VEHICLESJ

AIR CONDITIONING AND HEATER
GENERAL INFORMATION
On vehicles built with the 2.5L engine, the electri-
cal system has provisions for dealer installed air con-
ditioning. The provisions consist of two connectors
which include circuitry for:
²Circuit C1 - Ignition feed
²Circuit C21 - Blower motor switch
²Circuit C91 - A/C request signal
²Circuit C20 - A/C select signal
²Circuit C13 - Ground for coil side of A/C compres-
sor clutch relay
²Circuit G5 - Battery voltage for coil side of A/C
compressor clutch relay
A/C COMPRESSOR
When the ignition switch is in the RUN position it
connects circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) to circuit A22. Circuit A22 sup-
plies battery voltage to fuse 12 in the fuse block.
Fuse 12 powers circuit C1.
Circuit C1 supplies battery voltage to the A/C
blower switch. Circuit C21 connects the A/C blower
switch to the A/C low pressure switch.
When the operator selects A/C operation, the A/C
blower switch provides the A/C request signal to cav-
ity 27 of the Powertrain Control Module (PCM) on
circuit C91. At the same time, the blower switch sup-
plies voltage through the A/C thermostat to circuit
C21.
Circuit C21 supplies voltage to the A/C low pres-
sure switch. When the A/C low pressure switch
closes, circuit C20 provides battery voltage to the
contact side of the A/C compressor clutch relay and
provides the A/C select signal to the PCM. Circuit
C20 is double crimped at the contact side of the re-
lay. The C20 circuit branch from the relay supplies
the A/C select input to cavity 28 of the PCM.
After receiving the A/C request signal, the PCM en-
ergizes the A/C compressor clutch relay by providing
ground for the coil side of the relay on circuit C13.
Circuit C13 connects to cavity 34 of the PCM.
Circuit G5 from fuse 9 in the fuse block supplies
voltage to the coil side of the relay. In the START or
RUN positions the ignition switch connects circuit A1
from fuse 4 in the PDC with circuit A21. Circuit A21
connects to the fuse block bus bar that powers circuit
C5 through fuse 9.
When the PCM energizes the A/C compressor
clutch relay, the relay switches from its normally
grounded position to connect circuit C20 to circuit
C3. Circuit C3 supplies voltage to the case grounded
A/C compressor clutch.
HELPFUL INFORMATION
²Circuit G5 is double crimped at the coil side of the
A/C compressor clutch relay. The G5 branch from the
relay continues to the back-up lamp switch.
²Circuit Z1 provides ground for the A/C compressor
clutch relay when the relay is in its normally
grounded position.
A/C-HEATER BLOWER MOTOR
When the ignition switch is in the RUN position it
connects circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) to circuit A22. Circuit A22 sup-
plies battery voltage to fuse 12 in the fuse block.
Fuse 12 powers circuit C1.
Circuit C1 supplies battery voltage to the A/C
blower switch. In the LOW position, the A/C blower
switch supplies voltage to the low speed brush of the
blower motor. In the MEDIUM position, the switch
supplies voltage to the medium speed bush of the
blower motor. In the HIGH position, the switch sup-
plies voltage to the high speed brush of the blower
motor.
The blower motor has a field jumper. The ground
circuit for the blower motor connects to the cigar
lighter. Circuit Z1 provides ground for the blower mo-
tor and the cigar lighter.
HELPFUL INFORMATION
²Check fuse 4 in the PDC.
²Check fuse 12 in the fuse block.
DIAGRAM INDEX
Component Page
A/C Compressor Clutch.....................8W-42-4
A/C Compressor Clutch Relay................8W-42-4
A/C Thermostat..........................8W-42-5
Blower Motor...........................8W-42-5
Blower Motor Switch......................8W-42-5
Fuse 4 (PDC).........................8W-42-4, 6
Fuse 7 (Fuse Block).......................8W-42-6
Fuse 9 (Fuse Block).....................8W-42-4, 6
Fuse 12 (Fuse Block)....................8W-42-4, 6
Ignition Switch........................8W-42-4, 6
Powertrain Control Module.................8W-42-4, 6
8W - 42 - 2 8W-42 AIR CONDITIONING/HEATERÐYJ VEHICLESJ

minutes). The use of a locating dowel is recom-
mended during assembly to prevent smearing the
material off location.
Mopar Gasket Maker should be applied sparingly
to one gasket surface. The sealant diameter should
be 1.00 mm (0.04 inch) or less. Be certain the mate-
rial surrounds each mounting hole. Excess material
can easily be wiped off. Components should be
torqued in place within 15 minutes. The use of a lo-
cating dowel is recommended during assembly to pre-
vent smearing the material off location.
ENGINE PERFORMANCE
To provide best vehicle performance and lowest ve-
hicle emissions, it is most important that the tune-up
be done accurately. Use the specifications listed on
the Vehicle Emission Control Information label found
on the engine compartment hood.
(1) Test battery specific gravity. Add water, if nec-
essary. Clean and tighten battery connections.
(2) Test cranking amperage draw (refer to Group
8B, Battery/Starter Service for the proper proce-
dures).
(3) Tighten the intake manifold bolts (refer to
Group 11, Exhaust System and Intake Manifold for
the proper specifications).
(4) Perform cylinder compression test:
(a) Check engine oil level and add oil, if neces-
sary.
(b) Drive the vehicle until engine reaches normal
operating temperature.
(c) Select a route free from traffic and other
forms of congestion, observe all traffic laws and
briskly accelerate through the gears several times.
The higher engine speed may help clean out valve
seat deposits which can prevent accurate compres-
sion readings.
CAUTION: DO NOT overspeed the engine.
(d) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for ab-
normal firing indicatorsÐfouled, hot, oily, etc.
Record cylinder number of spark plug for future
reference.
(e) Disconnect coil wire from distributor and se-
cure to good ground to prevent a spark from start-
ing a fire.
(f) Be sure throttle blades are fully open during
the compression check.
(g) Insert compression gage adaptor into the
No.1 spark plug hole. Crank engine until maximum
pressure is reached on gauge. Record this pressure
as No.1 cylinder pressure.
(h) Repeat Step 4g for all remaining cylinders.
(i) Compression should not be less than 689 kPa
(100 psi) and not vary more than 172 kPa (25 psi)
from cylinder to cylinder.(j) If cylinder(s) have abnormally low compres-
sion pressures, repeat steps 4a through 4h.
(k) If the same cylinder(s) repeat an abnormally
low reading, it could indicate the existence of a
problem in the cylinder.
The recommended compression pressures are
to be used only as a guide to diagnosing engine
problems. An engine should NOT be disassem-
bled to determine the cause of low compression
unless some malfunction is present.
(5) Clean or replace spark plugs as necessary. Ad-
just gap (refer to Group 8D, Ignition System for gap
adjustment and torque).
(6) Test resistance of spark plug cables (refer to
Group 8D, Ignition System).
(7) Inspect the primary wire. Test coil output volt-
age, primary and secondary resistance. Replace parts
as necessary (refer to Group 8D, Ignition System and
make necessary adjustment).
(8) Perform a combustion analysis.
(9) Test fuel pump for pressure (refer to Group 14,
Fuel System for the proper specifications).
(10) Inspect air filter element (refer to Group 0,
Lubrication and Maintenance for the proper proce-
dure).
(11) Inspect crankcase ventilation system (refer to
Group 0, Lubrication and Maintenance for the proper
procedure).
(12) For emission controls refer to Group 25, Emis-
sion Controls System for service procedures.
(13) Inspect and adjust accessory belt drives (refer
to Group 7, Cooling System for the proper adjust-
ments).
(14) Road test vehicle as a final test.
HONING CYLINDER BORES
Before honing, stuff plenty of clean shop towels un-
der the bores and over the crankshaft to keep abra-
sive materials from entering the crankshaft area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823 equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). 20-60 strokes, de-
pending on the bore condition, will be sufficient to
provide a satisfactory surface. Using honing oil
C-3501-3880 or a light honing oil available from ma-
jor oil distributors.
9 - 2 ENGINESJ

CONNECTING ROD BEARING CLEARANCE
Engine connecting rod bearing clearances can be
determined by use of Plastigage, or equivalent. The
following is the recommended procedures for the use
of Plastigage:
(1) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(2) Place a piece of Plastigage across the entire width
of the bearing cap shell (Fig. 2). Position the Plastigage
approximately 6.35 mm (1/4 inch) off center and away
from the oil holes. In addition, suspect areas can be
checked by placing the Plastigage in the suspect area.
(3) The crankshaft must be turned until the connect-
ing rod to be checked starts moving toward the top of
the engine. Only then should the rod cap with Plasti-
gage in place be assembled. Tighten the rod cap nut to
45 Nzm (33 ft. lbs.) torque.DO NOT rotate the crank-
shaft or the Plastigage may be smeared, giving in-
accurate results.
(4) Remove the bearing cap and compare the width
of the flattened Plastigage with the scale provided on
the package (Fig. 3). Plastigage generally comes in 2
scales (one scale is in inches and the other is a met-
ric scale). Locate the band closest to the same width.
This band shows the amount of clearance. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken
(refer to Engine Specifications).
(5) Plastigage is available in a variety of clearance
ranges. The 0.025-0.076 mm (0.001-0.003 inch) range
is usually the most appropriate for checking engine
bearing clearances.
REPAIR DAMAGED OR WORN THREADS
Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole.
This brings the hole back to its original thread
size.
CAUTION: Be sure that the tapped holes maintain
the original center line.Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
SERVICE ENGINE ASSEMBLY (SHORT BLOCK)
A service replacement engine assembly (short
block) may be installed whenever the original cylin-
der block is defective or damaged beyond repair. It
consists of the cylinder block, crankshaft, piston and
rod assemblies. If needed, the camshaft must be pro-
cured separately and installed before the engine is
installed in the vehicle.
A short block is identified with the letter ``S'' stamped
on the same machined surface where the build date
code is stamped for complete engine assemblies.
Installation includes the transfer of components
from the defective or damaged original engine. Fol-
low the appropriate procedures for cleaning, inspec-
tion and torque tightening.
HYDROSTATIC LOCK
When an engine is suspected of hydrostatic lock
(regardless of what caused the problem), follow the
steps below.
(1) Perform the Fuel Pressure Release Procedure
(refer to Group 14, Fuel System).
(2) Disconnect the negative cable from the battery.
(3) Inspect air cleaner, induction system and in-
take manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure in
the cylinder head. Remove the plugs from the engine.
CAUTION: DO NOT use the starter motor to rotate
the crankshaft. Severe damage could occur.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
(6) Identify the fluid in the cylinders (i.e. coolant,
fuel, oil, etc.).
(7) Make sure all fluid has been removed from the
cylinders.
(8) Repair engine or components as necessary to
prevent this problem from occurring again.
(9) Squirt engine oil into the cylinders to lubricate
the walls. This will prevent damage on restart.
(10) Install new spark plugs. Tighten the spark
plugs to 37 Nzm (27 ft. lbs.) torque.
(11) Drain engine oil. Remove and discard the oil
filter.
(12) Install the drain plug. Tighten the plug to 34
Nzm (25 ft. lbs.) torque.
(13) Install a new oil filter.
(14) Fill engine crankcase with the specified
amount and grade of oil (refer to Group 0, Lubrica-
tion and Maintenance).
(15) Connect the negative cable to the battery.
(16) Start the engine and check for any leaks.
Fig. 3 Clearance Measurement
9 - 4 ENGINESJ

ENGINE DIAGNOSIS
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine tune-ups.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or me-
chanical (e.g., a strange noise).
Refer to the Service DiagnosisÐPerformance chart
and the Service DiagnosisÐMechanical chart for pos-
sible causes and corrections of malfunctions. Refer to
Group 14, Fuel System for the fuel system diagnosis.
GENERAL INFORMATION
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts. In-
formation concerning additional tests and diagnosis
is provided within the following diagnosis:
²Cylinder Compression Pressure Test.
²Cylinder Combustion Pressure Leakage Test.
²Engine Cylinder Head Gasket Failure Diagnosis.
²Intake Manifold Leakage Diagnosis.
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
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 DI-
RECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
METHOD 1
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM'S, the area of the suspected
leak has been found.
(4) Repair as required.
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cylin-
ders.
Refer to Engine Specifications for the correct en-
gine compression pressures.
ENGINE CYLINDER HEAD GASKET FAILURE
DIAGNOSIS
A leaking engine cylinder head gasket usually re-
sults in loss of power, loss of coolant and engine mis-
firing.
An engine cylinder head gasket leak can be located
between adjacent cylinders or between a cylinder and
the adjacent water jacket.
²An engine cylinder head gasket leaking between
adjacent cylinders is indicated by a loss of power
and/or engine misfire.
²An engine cylinder head gasket leaking between a
cylinder and an adjacent water jacket is indicated by
coolant foaming or overheating and loss of coolant.
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders; follow the proce-
dures outlined in Cylinder Compression Pressure
Test. An engine cylinder head gasket leaking between
adjacent cylinders will result in approximately a 50-
70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE
TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A DI-
RECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
Remove the radiator cap.
Start the engine and allow it to warm up until the
engine thermostat opens.
If a large combustion/compression pressure leak ex-
ists, bubbles will be visible in the coolant.
If bubbles are not visible, install a radiator pres-
sure tester and pressurize the coolant system.
If a cylinder is leaking combustion pressure into
the water jacket, the tester pointer will pulsate with
every combustion stroke of the cylinder.
JENGINES 9 - 5

CYLINDER COMBUSTION PRESSURE LEAKAGE
TEST
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1 379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
Perform the test procedures on each cylinder ac-
cording to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to the Cylinder Combustion Pressure Leak-
age Test Diagnosis chart.
INSPECTION (ENGINE OIL LEAKS IN GENERAL)
Begin with a through visual inspection of the en-
gine, particularly at the area of the suspected leak. If
an oil leak source is not readily identifiable, the fol-
lowing steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for ap-
proximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified, re-
pair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24km (15 miles), and
repeat step (3).
If the oil leak source is not positively identi-
fied at this time, proceed with the air leak detec-
tion test method as follows:
(1) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(2) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(3) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
(4) Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provide the best bubbles which
will pinpoint the leak source. If the oil leak is de-
tected and identified, repair per service manual pro-
cedures.
(5) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(6) If no leaks are detected, turn off the air supply
and remove the air hose and all plugs and caps. In-
stall the PCV valve and breather cap hose. Proceed
to step 7.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the en-
gine, a more involved inspection is necessary. The fol-
lowing steps should be followed to help pinpoint the
source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, distributor seal,
camshaft bore cup plugs oil galley pipe plugs, oil
9 - 6 ENGINESJ

filter runoff, and main bearing cap to cylinder
block mating surfaces. See Group 9, Engines for
proper repair procedures of these items.
(4) If no leaks are detected, pressurized the crank-
case as outlined in the, Inspection (Engine oil Leaks
in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is de-
tected between the crankshaft and seal while slowly
turning the crankshaft, it is possible the crankshaft
seal surface is damaged. The seal area on the crank-
shaft could have minor nicks or scratches that can be
polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.(6) For bubbles that remain steady with shaft ro-
tation, no further inspection can be done until disas-
sembled. Refer to the service DiagnosisÐMechanical,
under the Oil Leak row for components inspections
on possible causes and corrections.
(7) After the oil leak root cause and appropriate
corrective action have been identified, Refer to Group
9, EnginesÐCrankshaft Rear Oil Seals, for proper re-
placement procedures.
ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit.
(2) Install Oil Pressure Line and Gauge Tool
C-3292. Start engine and record pressure. Refer to
Oil Pressure in Engine Specifications for the proper
pressures.
CYLINDER COMBUSTION PRESSURE LEAKAGE TEST DIAGNOSIS
JENGINES 9 - 7

(a) Align the transmission torque converter hous-
ing with the engine.
(b) Loosely install the converter housing lower
bolts and install the next higher bolt and nut on
each side.
(c) Tighten all 4 bolts finger-tight.
(5) Install the engine support cushions (if re-
moved).
(6) Lower the engine and engine support cushions
onto the engine compartment brackets.
(7) Remove the engine lifting device.
(8) Raise the vehicle.
(9) If equipped with an automatic transmission:
(a) Install the converter-to-drive plate bolts. En-
sure the installation reference marks are aligned.
Tighten the bolts to 54 Nzm (40 ft. lbs.) torque.
(b) Install the converter-housing access cover.
(c) Install the exhaust pipe support.
(10) Install the remaining converter or flywheel
housing bolts.
(11) Install the starter motor and connect the ca-
ble. Tighten the bolts to 45 Nzm (33 ft. lbs.) torque.
(12) Tighten the engine support cushing through-
bolt nuts.
(13) Install the remaining flywheel and converter
housing bolts. Tighten the bolts to 38 Nzm (28 ft. lbs.)
torque.
(14) Connect the exhaust pipe to the manifold.
(15) Install the oil filter.
(16) Lower the vehicle.
(17) Connect the coolant hoses and tighten the
clamps.
(18) If equipped with power steering:
(a) Remove the protective caps
(b) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 Nzm (38 ft. lbs.)
torque.
(c) Fill the pump reservoir with fluid.
(19) Remove the pulley-to-water pump flange
alignment capscrew and install the fan and spacer or
Tempatrol fan assembly.
(20) Install the fan shroud and radiator and con-
denser (if equipped with air conditioning).
(21) Connect the radiator hoses.
(22) Connect the automatic transmission fluid
cooler pipes, if equipped.
(23) Connect the oxygen sensor wire connector.
(24) Connect the throttle valve rod and retainer.
Connect the throttle cable and install the rod. Install
the throttle valve rod spring.
(25) Connect the speed control cable, if equipped.
(26) Connect the fuel supply and return lines to
the throttle body.
(27) Connect all the vacuum hoses and wire con-
nectors.
(28) Connect the service valves to the A/C compres-
sor ports, if equipped with air conditioning.(29) Fill the power steering reservoir.
(30) Connect the battery cables.
(31) Install the hood.
(32) Install the air cleaner.
(33) Start the engine and inspect for leaks.
(34) Fill the cooling system.
(35) Stop the engine and check the fluid levels.
Add fluid, as required.
ENGINE ASSEMBLYÐYJ VEHICLES
REMOVAL
(1) Place a protective cloth over the windshield
frame. Raise the hood and rest it on the windshield
frame (Fig. 19).
(2) Disconnect the battery cable clamps and re-
move the battery.
WARNING: THE COOLANT IN A RECENTLY OPER-
ATED ENGINE IS HOT AND PRESSURIZED. USE
CARE TO PREVENT SCALDING BY HOT COOLANT.
CAREFULLY RELEASE THE PRESSURE BEFORE
REMOVING THE RADIATOR DRAIN COCK AND CAP.
(3) Remove the radiator drain cock and radiator
cap to drain the coolant. DO NOT waste usable cool-
ant. If the solution is clean, drain the coolant into a
clean container for reuse.
(4) Disconnect the wire connectors from the gener-
ator.
(5) Disconnect the ignition coil and distributor wire
connectors.
(6) Disconnect the oil pressure sender wire connec-
tor.
Fig. 19 Hood on Windshield Frame
9 - 20 2.5L ENGINEJ