Following are paragraphs that briefly describe the
operation of each of the front wiper and washer sys-
tem operating modes.
CONTINUOUS WIPE MODE When the Low posi-
tion of the control knob on the right (wiper) control
stalk of the multi-function switch is selected, the
Body Control Module (BCM) energizes the wiper
on/off relay. This directs battery current through the
normally open contacts of the energized wiper on/off
relay and the normally closed contacts of the de-en-
ergized wiper high/low relay to the low speed brush
of the front wiper motor, causing the front wipers to
cycle at low speed. When the High position of the
control knob is selected, the BCM energizes both the
wiper on/off relay and the wiper high/low relay. This
directs battery current through the normally open
contacts of the energized wiper on/off relay and the
normally open contacts of the energized wiper high/
low relay to the high speed brush of the front wiper
motor, causing the front wipers to cycle at high
speed.
When the Off position of the control knob is
selected, the BCM de-energizes both the wiper on/off
and wiper high low relays, then one of two events
will occur. The event that occurs depends upon the
position of the wiper blades on the windshield at the
moment that the control knob Off position is selected.
If the wiper blades are in the down position on the
windshield when the Off position is selected, the
park switch that is integral to the front wiper motor
is closed to ground and the wiper motor ceases to
operate. If the wiper blades are not in the down posi-
tion on the windshield at the moment the Off posi-
tion is selected, the park switch is closed to battery
current from the fused ignition switch output (run-
acc) circuit of the front wiper motor. The park switch
directs this battery current to the low speed brush of
the wiper motor through the wiper park switch sense
circuit and the normally closed contacts of the de-en-
ergized wiper on/off and wiper high/low relays. This
causes the wiper motor to continue running at low
speed until the wiper blades are in the down position
on the windshield and the park switch is again
closed to ground.
INTERMITTENT WIPE MODE When the control
knob on the right (wiper) control stalk of the multi-
function switch is moved to one of the Delay interval
positions, the BCM electronic intermittent wipe logic
circuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The BCM monitors the chang-
ing state of the wiper motor park switch through a
hard wired front wiper park switch sense circuit
input. This input allows the BCM to determine the
proper intervals at which to energize and de-energize
the wiper on/off relay to operate the front wipermotor intermittently for one low speed cycle at a
time. The BCM logic is also programmed to provide
an immediate wipe cycle and begin a new delay
interval timing cycle each time a shorter delay inter-
val is selected, and to add the remaining delay tim-
ing interval to the new delay interval timing before
the next wipe cycle occurs each time a longer delay
interval is selected.
MIST WIPE MODE When the right (wiper) control
stalk of the multi-function switch is moved to the
momentary Mist position, the BCM energizes the
wiper on/off relay for as long as the Mist switch is
held closed, then de-energizes the relay when the
state of the Mist switch input changes to open. The
BCM can operate the front wiper motor in this mode
for only one low speed cycle at a time, or for an
indefinite number of sequential low speed cycles,
depending upon how long the Mist switch is held
closed.
WASH MODE When the right (wiper) control stalk
of the multi-function switch is moved to the momen-
tary front Wash position while the control knob is in
the Low or High positions, the circuitry within the
switch directs battery current and ground to the
washer pump/motor unit. This will cause the washer
pump/motor unit to be energized for as long as the
front Wash switch is held closed, and to de-energize
when the front Wash switch is released. When the
right (wiper) control stalk of the multi-function
switch is moved to the momentary front Wash posi-
tion while the control knob is in one of the Delay
interval positions, the front washer pump/motor oper-
ation is the same. However, the BCM energizes the
wiper on/off relay to override the selected delay inter-
val and operate the front wiper motor in a continu-
ous low speed mode for as long as the front Wash
switch is held closed, then de-energizes the relay and
reverts to the selected delay mode interval several
wipe cycles after the front Wash switch is released.
The BCM detects the front Wash switch state
through a hard wired washer pump driver circuit
input from the multi-function switch.
WIPE-AFTER-WASH MODE When the right
(wiper) control stalk of the multi-function switch is
moved to the momentary front Wash position while
the control knob is in the Off position, the BCM
detects that switch state through a hard wired
washer pump driver circuit input from the multi-
function switch. The BCM responds to this input by
energizing the wiper on/off relay for as long as the
Wash switch is held closed, then de-energizes the
relay several wipe cycles after the front Wash switch
is released. The BCM monitors the changing state of
the wiper motor park switch through a hard wired
front wiper park switch sense circuit input. This
input allows the BCM to count the number of wipe
KJFRONT WIPERS/WASHERS 8R - 5
FRONT WIPERS/WASHERS (Continued)
cycles that occur after the front Wash switch state
changes to open, and to determine the proper inter-
val at which to de-energize the wiper on/off relay to
complete the wipe-after-wash mode cycle.
DIAGNOSIS AND TESTING - FRONT WIPER &
WASHER SYSTEM
FRONT WIPER SYSTEM
If the front wiper motor operates, but the wipers
do not move on the windshield, replace the faulty
front wiper module. If the wipers operate, but chat-
ter, lift, or do not clear the glass, clean and inspect
the front wiper system components as required.
(Refer to 8 - ELECTRICAL/FRONT WIPERS/WASH-
ERS - INSPECTION) and (Refer to 8 - ELECTRI-
CAL/FRONT WIPERS/WASHERS - CLEANING). For
diagnosis and testing of the multi-function switch
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/MULTI-FUNCTION SWITCH - DIAG-
NOSIS AND TESTING). Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
The hard wired circuits and components of the
front wiper and washer system may be diagnosed
and tested using conventional diagnostic tools and
procedures. However, conventional diagnostic meth-
ods may not prove conclusive in the diagnosis of the
Body Control Module (BCM), or the inputs to or out-
puts from the BCM that control the various front
wiper and washer system operating modes. The most
reliable, efficient, and accurate means to diagnose
the BCM, or the BCM inputs and outputs related to
the various front wiper and washer system operating
modes requires the use of a DRBIIItscan tool. Refer
to the appropriate diagnostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULDRESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
FRONT WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative front washer system. If the washer
pump/motor operates, but no washer fluid is emitted
from the front washer nozzles, be certain to check
the fluid level in the reservoir. Also inspect the front
washer system components as required. (Refer to 8 -
ELECTRICAL/FRONT WIPERS/WASHERS -
INSPECTION). Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control knob on the right (wiper) control
stalk of the multi-function switch to the On position.
Check whether the front wiper system is operating.
If OK, go to Step 2. If not OK, test and repair the
front wiper system before continuing with these
tests. Refer to FRONT WIPER SYSTEM .
(2) Turn the control ring on the right (wiper) con-
trol stalk of the multi-function switch to the rear
Wash position. Check whether the rear washer sys-
tem is operating. If OK, test the multi-function
switch. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/MULTI-FUNCTION SWITCH -
DIAGNOSIS AND TESTING). If the multi-function
switch tests OK, go to Step 3. If the multi-function
switch does not test OK, replace the faulty switch.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the headlamp and dash wire harness con-
nector for the washer pump/motor unit from the
pump/motor unit connector receptacle. Check for con-
tinuity between the washer pump driver circuit cav-
8R - 6 FRONT WIPERS/WASHERSKJ
FRONT WIPERS/WASHERS (Continued)
OPERATION
The front check valve provides more than one func-
tion in this application. It serves as a wye connector
fitting between the cowl grille panel and washer noz-
zle sections of the front washer supply hose. It also
prevents washer fluid from draining out of the front
washer supply hoses back to the washer reservoir.
This drain-back would result in a lengthy delay when
the front washer switch is actuated until washer
fluid was dispensed through the front washer noz-
zles, because the washer pump would have to refill
the front washer plumbing from the reservoir to the
nozzles. Finally, the front check valve prevents
washer fluid from siphoning through the front
washer nozzles after the front washer system is
turned Off.
Within the check valve body, a small check valve is
held in place against a seat by a small coiled spring
to restrict flow through the unit until the valve is
unseated by a predetermined inlet fluid pressure.
When the washer pump pressurizes and pumps
washer fluid from the reservoir through the front
washer plumbing, the fluid pressure overrides the
spring pressure applied to the check valve and
unseats the valve, allowing washer fluid to flow
toward the front washer nozzles. When the washer
pump stops operating, spring pressure seats the
check valve and fluid flow in either direction within
the front washer plumbing is prevented.
REMOVAL
(1) Unlatch and open the hood.
(2) Remove both front wiper arms from the wiper
pivots. (Refer to 8 - ELECTRICAL/WIPERS/WASH-
ERS - FRONT/FRONT WIPER ARM - REMOVAL).
(3) Remove the cowl plenum cover/grille panel
from over the cowl plenum. (Refer to 23 - BODY/EX-
TERIOR/COWL GRILLE - REMOVAL).
(4) From the underside of the cowl plenum cover/
grille panel, disconnect the cowl plenum and washer
nozzle hoses from the three barbed nipples of the
front check valve (Fig. 4).
(5) Remove the front check valve from the under-
side of the cowl plenum cover/grille panel.
INSTALLATION
(1) Position the front check valve to the underside
of the cowl plenum cover/grille panel (Fig. 4). Be cer-
tain that the flow direction arrow molded into the
front check valve body is oriented towards the front
washer nozzles.
(2) From the underside of the cowl plenum cover/
grille panel, reconnect the cowl plenum and washer
nozzle hoses to the three barbed nipples of the front
check valve.
(3) Reinstall the cowl plenum cover/grille panel
over the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - INSTALLATION).
(4) Reinstall both front wiper arms onto the wiper
pivots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARM - INSTALLATION).
(5) Close and latch the hood.
Fig. 3 Front Check Valve
1 - INLET NIPPLE
2 - FRONT CHECK VALVE
3 - OUTLET NIPPLE (2)
4 - FLOW DIRECTION ARROW
Fig. 4 Front Check Valve Remove/Install
1 - WASHER NOZZLE HOSE (RIGHT)
2 - FRONT CHECK VALVE
3 - COWL PLENUM WASHER HOSE
4 - ROUTING CLIP
5 - COWL GRILLE COVER (UNDERSIDE)
6 - WASHER NOZZLE HOSE (LEFT)
KJFRONT WIPERS/WASHERS 8R - 9
FRONT CHECK VALVE (Continued)
REAR WASHER SYSTEM
The washer system components should be
inspected periodically, not just when washer perfor-
mance problems are experienced. This inspection
should include the following points:
(1) Check for ice or other foreign material in the
washer reservoir. If contaminated, clean and flush
the washer system. (Refer to 8 - ELECTRICAL/
REAR WIPERS/WASHERS - CLEANING).
(2) Inspect the washer plumbing for pinched, leak-
ing, deteriorated, or incorrectly routed hoses and
damaged or disconnected hose fittings. Replace dam-
aged or deteriorated hoses and hose fittings. Leaking
washer hoses can sometimes be repaired by cutting
the hose at the leak and splicing it back together
using an in-line connector fitting. Similarly, sections
of deteriorated hose can be cut out and replaced by
splicing in new sections of hose using in-line connec-
tor fittings. Whenever routing a washer hose or a
wire harness containing a washer hose, it must be
routed away from hot, sharp, or moving parts. Also,
sharp bends that might pinch the washer hose must
be avoided.
REAR CHECK VALVE
DESCRIPTION
A rear washer system check valve is standard
equipment on this model (Fig. 3). The rear check
valve is located in the washer plumbing between the
rear roof header and the roof outer panel near the
rear washer nozzle. The rear check valve consists of
a molded plastic body with a round center sectionand barbed hose nipples at each end. An arrow for-
mation molded into the center section of the valve
body indicates the direction of flow through the
valve. The rear check valve cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The rear check valve prevents washer fluid from
draining out of the rear washer supply hoses back to
the washer reservoir. This drain-back would result in
a lengthy delay from when the rear washer switch is
actuated until washer fluid was dispensed through
the rear washer nozzle, because the washer pump
would have to refill the rear washer plumbing from
the reservoir to the nozzle. The check valve also pre-
vents washer fluid from siphoning through the rear
washer nozzle after the rear washer system is turned
Off.
Within the check valve body, a small check valve is
held in place against a seat by a small coiled spring
to restrict flow through the unit until the valve is
unseated by a predetermined inlet fluid pressure.
When the washer pump pressurizes and pumps
washer fluid from the reservoir through the rear
washer plumbing, the fluid pressure overrides the
spring pressure applied to the check ball within the
valve and unseats the valve, allowing washer fluid to
flow toward the rear washer nozzle. When the
washer pump stops operating, spring pressure seats
the check valve and fluid flow in either direction
within the rear washer plumbing is prevented.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Center High Mounted Stop Lamp
(CHMSL) unit from the rear of the roof panel. (Refer
to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTERI-
OR/CENTER HIGH MOUNTED STOP LAMP UNIT
- REMOVAL).
WARNING: THE EDGES OF THE SHEET METAL
AROUND THE CENTER HIGH MOUNTED STOP
LAMP MOUNTING HOLE IN THE ROOF PANEL.
TAKE THE PROPER PRECAUTIONS TO AVOID PER-
SONAL INJURY.
(3) Reach through the CHMSL unit mounting hole
in the rear of the roof panel to access and disconnect
the rear washer hose at the barbed nipple of the rear
washer nozzle (Fig. 4).
(4) Pull the rear washer hose through the CHMSL
unit mounting hole far enough to access and discon-
nect the headliner washer hose from the barbed nip-
ple of the rear check valve.
Fig. 3 Rear Check Valve
1 - INLET NIPPLE
2 - REAR CHECK VALVE
3 - OUTLET NIPPLE
4 - FLOW DIRECTION ARROW
8R - 34 REAR WIPERS/WASHERSKJ
REAR WIPERS/WASHERS (Continued)
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are
six steps which can aid in the procedure. The steps
are listed and explained below. Always check for non-
factory items added to the vehicle before doing any
diagnosis. If the vehicle is equipped with these items,
disconnect them to verify these add-on items are not
the cause of the problem.
(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are
in the same circuit. Refer to the wiring diagrams.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem area.
(6) Verify the proper operation. For this step,
check for proper operation of all items on the
repaired circuit. Refer to the wiring diagrams.
STANDARD PROCEDURE
STANDARD PROCEDURE - ELECTROSTATIC
DISCHARGE (ESD) SENSITIVE DEVICES
All ESD sensitive components are solid state and a
symbol (Fig. 6) is used to indicate this. When han-
dling any component with this symbol, comply with
the following procedures to reduce the possibility of
electrostatic charge build up on the body and inad-
vertent discharge into the component. If it is not
known whether the part is ESD sensitive, assume
that it is.
(1) Always touch a known good ground before han-
dling the part. This should be repeated while han-
dling the part and more frequently after sliding
across a seat, sitting down from a standing position,
or walking a distance.
(2) Avoid touching electrical terminals of the part,
unless instructed to do so by a written procedure.
(3) When using a voltmeter, be sure to connect the
ground lead first.
(4) Do not remove the part form it's protective
packing until it is time to install the part.
(5) Before removing the part from it's pakage,
ground the pakage to a known good ground on the
vehicle.
STANDARD PROCEDURE - TESTING OF
VOLTAGE POTENTIAL
(1) Connect the ground lead of a voltmeter to a
known good ground (Fig. 7).
(2) Connect the other lead of the voltmeter to the
selected test point. The vehicle ignition may need to
be turned ON to check voltage. Refer to the appropri-
ate test procedure.
STANDARD PROCEDURE - TESTING FOR
CONTINUITY
(1) Remove the fuse for the circuit being checked
or, disconnect the battery.
(2) Connect one lead of the ohmmeter to one side
of the circuit being tested (Fig. 8).
(3) Connect the other lead to the other end of the
circuit being tested. Low or no resistance means good
continuity.
Fig. 6 ELECTROSTATIC DISCHARGE SYMBOL
Fig. 7 TESTING FOR VOLTAGE POTENTIAL
8Wa - 01 - 8 8W-01 WIRING DIAGRAM INFORMATIONKJ
WIRING DIAGRAM INFORMATION (Continued)
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor 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.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise the vehicle on a hoist.
(3) Disconnect the exhaust pipe at the left side
exhaust manifold.
(4) Drain the engine coolant. Refer to COOLING
SYSTEM.
(5) Lower the vehicle.
(6) Remove the intake manifold. Refer to proce-
dure in this section.
(7) Remove the cylinder head cover. Refer to proce-
dure in this section.
(8) Remove the fan shroud and fan blade assembly.
Refer to COOLING SYSTEM.
(9) Remove accessory drive belt. Refer to COOL-
ING SYSTEM.
(10) Remove the power steering pump and set
aside.
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark (Fig. 4).
(12) Verify the V6 mark on the camshaft sprocket
is at the 12 o'clock position (Fig. 5). Rotate the crank-
shaft one turn if necessary.
(13) Remove the crankshaft damper. Refer to Pro-
cedure.
(14) Remove the timing chain cover. Refer to pro-
cedure.
Fig. 4 Engine Top Dead Center
1 - TIMING CHAIN COVER
2 - CRANKSHAFT TIMING MARKS
9 - 20 ENGINE - 3.7LKJ
CYLINDER HEAD - LEFT (Continued)
(9) Using Special Tool 8516 Valve Spring Compres-
sor, install the rocker arms and the hydraulic lash
adjusters.
(10) Install the cylinder head cover. Refer to Cylin-
der Head Cover in this Section.
CYLINDER HEAD - RIGHT
DESCRIPTION
DESCRIPTION - CYLINDER HEAD
The cylinder heads are made of an aluminum alloy.
The cylinder head features two valves per cylinder
with pressed in powdered metal valve guides. The
cylinder heads also provide enclosures for the timing
chain drain, necessitating unique left and right cylin-
der heads.
DESCRIPTION - VALVE GUIDES
The valve guides are made of powered metal and
are pressed into the cylinder head. The guides are
not replaceable or serviceable, and valve guide ream-
ing is not recommended. If the guides are worn
beyond acceptable limits, replace the cylinder heads.
DESCRIPTION
The valves are made of heat resistant steel and
have chrome plated stems to prevent scuffing. Each
valve is actuated by a roller rocker arm which pivots
on a stationary lash adjuster. All valves use three
bead lock keepers to retain the springs and promote
valve rotation.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HYDRAULIC LASH
ADJUSTER
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may
cause aerated oil to enter the adjusters and cause
them to be spongy.
(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) Turn engine off and let set for a few minutes
before restarting. Repeat this several times after
engine has reached normal operating temperature.
(4) Low oil pressure.
(5) The oil restrictor in cylinder head gasket or the
oil passage to the cylinder head is plugged with
debris.(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Oil leak or excessive cam bore wear in cylin-
der head.
(11) Faulty lash adjuster.
²Check lash adjusters for sponginess while
installed in cylinder head and cam on camshaft at
base circle. Depress part of rocker arm over adjuster.
Normal adjusters should feel very firm. Spongy
adjusters can be bottomed out easily.
²Remove suspected lash adjusters, and replace.
²Before installation, make sure adjusters are at
least partially full of oil. This can be verified by little
or no plunger travel when lash adjuster is depressed.
DIAGNOSIS AND TESTING - CYLINDER 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 misfiring
²Poor 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.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
9 - 30 ENGINE - 3.7LKJ
VALVE SPRINGS (Continued)
Once the block has been completely cleaned, apply
Loctite PST pipe sealant with Teflon 592 to the
threads of the front and rear oil galley plugs. Tighten
the plugs to 34 N´m (25 ft. lbs.) torque.
INSPECTION
(1) It is mandatory to use a dial bore gauge to
measure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore gauge,
capable of reading in 0.003 mm (.0001 in.) INCRE-
MENTS is required. If a bore gauge is not available,
do not use an inside micrometer (Fig. 33).
(2) Measure the inside diameter of the cylinder
bore at three levels below top of bore. Start perpen-
dicular (across or at 90 degrees) to the axis of the
crankshaft and then take two additional reading.
(3) Measure the cylinder bore diameter crosswise
to the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the bore.
(4) Determine taper by subtracting the smaller
diameter from the larger diameter.
(5) Rotate measuring device 90É and repeat steps
above.(6) Determine out-of-roundness by comparing the
difference between each measurement.
(7) If cylinder bore taper does not exceed 0.025
mm (0.001 inch) and out-of-roundness does not
exceed 0.025 mm (0.001 inch), the cylinder bore can
be honed. If the cylinder bore taper or out- of-round
condition exceeds these maximum limits, the cylinder
block must be replaced. A slight amount of taper
always exists in the cylinder bore after the engine
has been in use for a period of time.
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - CONNECTING ROD
BEARING - FITTING
Inspect the connecting rod bearings for scoring and
bent alignment tabs (Fig. 34) (Fig. 35). Check the
bearings for normal wear patterns, scoring, grooving,
fatigue and pitting (Fig. 36). Replace any bearing
that shows abnormal wear.
Inspect the connecting rod journals for signs of
scoring, nicks and burrs.
Fig. 33 Bore GaugeÐTypical
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 38 MM (1.5 in)
Fig. 34 Connecting Rod Bearing Inspection
1 - UPPER BEARING HALF
2 - MATING EDGES
3 - GROOVES CAUSED BY ROD BOLTS SCRATCHING
JOURNAL DURING INSTALLATION
4 - WEAR PATTERN Ð ALWAYS GREATER ON UPPER
BEARING
5 - LOWER BEARING HALF
9 - 40 ENGINE - 3.7LKJ
ENGINE BLOCK (Continued)