check oil DODGE NEON 2000 Service Owner's Guide

To diagnose the cluster lamps first place the clus-
ter in self-diagnostic mode. With the ignition switch
in the off position, press the trip odometer reset but-
ton down. Simultaneously turn the ignition key to
the ON position and release the trip reset button. All
the indicator lamps and VF displays should illumi-
nate except for the fog lamp, turn signal, and high
beam select indicators. Refer to (Fig. 2), (Fig. 3), and
the Cluster Identification table.
1 ± FOG LAMP
2 ± BRAKE**
3 ± TRAC OFF**
4 ± ABS**
5 ± SPEEDOMETER
6 ± LEFT/RIGHT TURN SIGNAL
7 ± HIGH BEAM
8 ± TACHOMETER
9 ± OIL PRESSURE**
10 ± SEAT BELT**
11 ± BATTERY**
12 ± AIR BAG**
13 ± SECURITY*
14 ± FUEL FILLER DOOR LOCATOR
15 ± FUEL GAUGE
16 ± LOW FUEL*
17 ± MALFUNCTION INDICATOR LAMP (MIL)**
18 ± TRIP RESET BUTTON
19 ± TRAC**
20 ± ODOMETER**
21 ± DOOR (AJAR)**
22 ± SET CRUISE*
23 ± TRIP**
24 ± CRUISE*
25 ± TEMPERATURE GAUGE
*ILLUMINATE DURING SELF-DIAGNOSTICS
**ILLUMINATE DURING BULB CHECK AND SELF-DIAGNOSTICS
LOW OIL PRESSURE WARNING LAMP TEST
The low oil pressure warning lamp will illuminate
when the ignition switch is turned to the ON position
without engine running. The lamp also illuminates if
the engine oil pressure drops below a safe oil pres-
sure level.To test the system, turn the ignition switch to the
ON position. If the lamp fails to light, inspect for a
broken or disconnected wire at the oil pressure
switch, located at the front of the engine (Fig. 4). If
the wire at the connector checks good, pull the con-
nector loose from the switch and with a jumper wire,
ground the connector to the engine. With the ignition
switch turned to the ON position, check the warning
lamp. If the lamp still fails to light, inspect for a
burned out lamp or disconnected socket in the clus-
ter.
Fig. 2 Base Instrument Cluster Without Tachometer
Fig. 3 Premium Instrument Cluster With Tachometer
1 ± FOG LAMP
2 ± BRAKE**
3 ± TRAC OFF**
4 ± ABS**
5 ± SPEEDOMETER
6 ± LEFT/RIGHT TURN SIGNAL
7 ± HIGH BEAM
8 ± TACHOMETER
9 ± OIL PRESSURE**
10 ± SEAT BELT**
11 ± BATTERY**
12 ± AIR BAG**
13 ± SECURITY*
14 ± FUEL FILLER DOOR LOCATOR
15 ± FUEL GAUGE
16 ± LOW FUEL*
17 ± MALFUNCTION INDICATOR LAMP (MIL)**
18 ± TRIP RESET BUTTON
19 ± TRAC**
20 ± ODOMETER**
21 ± DOOR (AJAR)**
22 ± SET CRUISE*
23 ± TRIP**
24 ± CRUISE*
25 ± TEMPERATURE GAUGE
*ILLUMINATE DURING SELF-DIAGNOSTICS
**ILLUMINATE DURING BULB CHECK AND SELF-DIAGNOSTICS
PLINSTRUMENT PANEL SYSTEMS 8E - 3
DIAGNOSIS AND TESTING (Continued)

MULTIPLE/INDIVIDUAL GAUGES INOPERATIVE
Test speedometer, tachometer and other gauges for
malfunction:
(1) Remove the cluster. Refer to Cluster Removal
and Installation.
(2) Check for ignition voltage at Pin 15 of the clus-
ter wire harness connector (Fig. 5). Check for battery
voltage at Pin 21 of the connector. If no voltage,
repair as necessary.
(3) Check Pin 10 of the connector for continuity to
ground. If no ground, repair as necessary.
(4) If the voltage and ground are OK, and the pins
or the connectors are not distorted, replace the
instrument cluster.
(5) Install cluster. Refer to Instrument Cluster
Removal and Installation in this section.
SERVICE PROCEDURES
INSTRUMENT CLUSTER SELF-DIAGNOSTICS
To put the cluster in self-diagnostics mode press
the trip reset button down and then turn the ignition
to the RUN position simultaneously, then release the
button. The gauges will increment to selected stoops
and all indicators will light with the exception of the
turn signals, high beam, and fog lamp indicators.
The oil lamp will come on when the ignition is
turned ON and the engine is OFF.
REMOVAL AND INSTALLATION
ACCESSORY SWITCH/POWER OUTLET BEZEL
REMOVAL
(1) Disconnect and isolate the battery negative
cable (Fig. 6).
(2) Remove the instrument panel center bezel.
Refer to Instrument Panel Center Bezel Removal and
Installation in this section.
(3) Remove four screws retaining accessory switch/
power outlet bezel (Fig. 7).(4) Disconnect the harness connectors to the fol-
lowing:
²Rear Window Defogger Switch (if equipped)
²Traction Control Switch (if equipped)
²Cigar Lighter/Power Outlet
Fig. 5 Cluster Wire Harness Connector
INSTRUMENT CLUSTER CONNECTOR PIN
CALL-OUT
PIN DESCRIPTION PIN DESCRIPTION
1 REAR FOG
LAMP FEED14 PARK LAMP
SWITCH
OUTPUT
2 PCI BUS 15 FUSED IGNITION
SWITCH
OUTPUT
(RUN-START)
3 COURTESY
LAMPS DRIVER16 DAYTIME
RUNNING
LAMPS
4 FOG LAMP
SWITCH
OUTPUT17 DAYTIME
RUNNING
LAMPS
5 VTSS
INDICATOR
DRIVER18 LEFT TURN
SIGNAL
6 PANEL LAMPS
DIMMER
SIGNAL19 RIGHT TURN
SIGNAL
7 FUEL LEVEL
SENSOR
SIGNAL20 DIMMER
SWITCH LOW
BEAM OUTPUT
8 NOT USED 21 FUSED B+
9 NOT USED 22 RED BRAKE
WARNING
INDICATOR
DRIVER
10 GROUND 23 KEY-IN IGNITION
SWITCH SENSE
11 NOT USED 24 DRIVER DOOR
AJAR SWITCH
SENSE
12 PANEL LAMPS
DRIVER25 SEAT BELT
SWITCH SENSE
13 KEYLESS
ENTRY SIGNAL26 DIMMER
SWITCH HIGH
BEAM OUTPUT
Fig. 4 Oil Pressure Switch
8E - 4 INSTRUMENT PANEL SYSTEMSPL
DIAGNOSIS AND TESTING (Continued)

HORNS
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
INTRODUCTION..........................1
DIAGNOSIS AND TESTING
HORN..................................2
HORN RELAY............................2
HORN SWITCH...........................2HORN SYSTEM TEST......................2
REMOVAL AND INSTALLATION
HORN..................................4
HORN RELAY............................4
HORN SWITCH...........................5
DESCRIPTION AND OPERATION
INTRODUCTION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAG, SEE GROUP 8M, PASSIVE RESTRAINT SYS-
TEMS FOR STEERING WHEEL REMOVAL.
The horn circuit consists of a horn switch, horn
relay, and horn. The horn circuit feed is from the fuse
to the horn relay in the Power Distribution Center
(PDC). The PDC is mounted on the battery tray.
When the horn switch is depressed, it completes the
ground circuit. The horn relay coil closes contacts
and allows current to flow to the horn. The horn is
grounded to the headlamp ground connection (Fig. 1).
HORN SWITCH
The horn switch is mounted between the outer and
inner cover of the Driver Airbag Module (Fig. 2).
When the Driver Airbag is pressed the horn switch
makes contact to ground. The ground signal is car-
ried to the horn relay and the horn sounds.
(1) The horn switch grounds to the airbag housing.
(2) If horn does not sound check for corrosion:
²Horn wire
²Horn switch ground connected to airbag metal
housing
²Airbag to steering wheel
²Ensure horn wire is properly connected and
insulator is in place on wire
(3) Refer to Group 8W, Wiring Diagrams if wire
circuit needs to be repaired.
Fig. 1 Horn System
1 ± CLOCK SPRING
2 ± HORN RELAY
3 ± 15 AMP FUSE
4 ± HEAD LAMP GROUND
5 ± HORN
6 ± HORN SWITCH
Fig. 2 Horn Switch
1 ± AIRBAG MODULE
2 ± HORN SWITCH
PLHORNS 8G - 1

INSTRUMENT
CLUSTER
A (8W-40-5)
21
193
AIRBAG
CONTROL
MODULE
FUEL
PUMP
MODULE
MODULE ENTRY
KEYLESS
REMOTEFROM
C104
A12C30512G4
18
DB
G4
18
DB
D25
18
VT/YLD25
20
VT/YLD25
22
VT/YL
D25
22
VT/YL
S217
FUEL
LEVEL
SENSOR
SIGNALPCI
BUS
BUSPCI
BUSPCI
VT/YL22 D25
2
MODULE IMMOBILIZER
KEY
SENTRY
2 7
INSTRUMENT
PANEL
DRIVERS
SPEEDOMETER FUEL
GAUGE
INDICATOR PRESSURE
OIL
LOW BRAKE
WARNING
INDICATOR TRACTION
OFF
INDICATOR AIRBAG
WARNING
INDICATORLOW
FUEL
INDICATOR ABS
INDICATOR CHECK
ENGINE
INDICATOR
GAUGE TEMPERATURE
COOLANT
ENGINE TACHOMETER
ODOMETER/TRIP
INDICATOR AJAR
DOOR TRACTION
CONTROL
OFF
INDICATOR INDICATOR
ENGAGED
CRUISE(8W-43-2)
(8W-30-10)
(8W-39-10)
(8W-39-11) (8W-39-3)
(8W-30-4)
8W - 40 - 6 8W-40 INSTRUMENT CLUSTERPL
008W-10PLI04006

ENGINE
TABLE OF CONTENTS
page page
STANDARD SERVICE PROCEDURES........... 1
ENGINE DIAGNOSIS........................ 82.0L SOHC ENGINE....................... 15
STANDARD SERVICE PROCEDURES
TABLE OF CONTENTS
page page
GENERAL INFORMATION
FORM-IN-PLACE GASKETS & SEALERS........1
ENGINE GASKET SURFACE PREPARATION.....2
CRANKSHAFT DAMPER BOLT ACCESS PLUG . . . 2
ENGINE CORE PLUGS.....................2
ENGINE PERFORMANCE...................3HONING CYLINDER BORES.................3
MEASURING WITH PLASTIGAGE.............4
REPAIR OF DAMAGED OR WORN THREADS....5
HYDROSTATIC LOCKED ENGINE.............5
CHECKING ENGINE OIL LEVEL..............6
ENGINE OIL SERVICE......................7
GENERAL INFORMATION
FORM-IN-PLACE GASKETS & SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
when applying form-in-place gaskets to assure
obtaining the desired results.Do not use form-in-
place gasket material unless specified.Bead size,
continuity, and location are of great importance. Too
thin a bead can result in leakage while too much can
result in spill-over which can break off and obstruct
fluid feed lines. A continuous bead of the proper
width is essential to obtain a leak-free gasket.
There are numerous types of form-in-place gasket
materials that are used in the engine area. Mopart
Engine RTV GEN II, MopartATF-RTV, and Mopart
Gasket Maker gasket materials, each have different
properties and can not be used in place of the other.
MOPARtENGINE RTV GEN II
MopartEngine RTV GEN II is used to seal com-
ponents exposed to engine oil. This material is a spe-
cially designed black silicone rubber RTV that
retains adhesion and sealing properties when
exposed to engine oil. Moisture in the air causes the
material to cure. This material is available in three
ounce tubes and has a shelf life of one year. After one
year this material will not properly cure. Alwaysinspect the package for the expiration date before
use.
MOPARtATF RTV
MopartATF RTV is a specifically designed black
silicone rubber RTV that retains adhesion and seal-
ing properties to seal components exposed to auto-
matic transmission fluid, engine coolants, and
moisture. This material is available in three ounce
tubes and has a shelf life of one year. After one year
this material will not properly cure. Always inspect
the package for the expiration date before use.
MOPARtGASKET MAKER
MopartGasket Maker is an anaerobic type gasket
material. The material cures in the absence of air
when squeezed between two metallic surfaces. It will
not cure if left in the uncovered tube. The anaerobic
material is for use between two machined surfaces.
Do not use on flexible metal flanges.
MOPARtBED PLATE SEALANT
MopartBed Plate Sealant is a unique (green-in-
color) anaerobic type gasket material that is specially
made to seal the area between the bedplate and cyl-
inder block without disturbing the bearing clearance
or alignment of these components. The material
cures slowly in the absence of air when torqued
between two metallic surfaces, and will rapidly cure
when heat is applied.
PLENGINE 9 - 1

CAUTION: Do not drive cup plug into the casting
as restricted cooling can result and cause serious
engine problems.
INSTALLATION
Thoroughly clean all debris/rust from inside of cup
plug hole in cylinder block or head. Be sure to
remove old sealer. Lightly coat inside of cup plug hole
with MopartStud and Bearing Mount Adhesive.
Make certain the new plug is cleaned of all oil or
grease. Using a proper driver, drive plug into hole so
that the sharp edge of the plug is at least 0.5 mm
(0.020 inch.) inside the lead in chamfer (Fig. 3).
It is not necessary to wait for curing of the sealant.
The cooling system can be refilled and the vehicle
placed in service immediately.
ENGINE PERFORMANCE
If a loss of performance is noticed, timing belt or
chain may have skipped one or two teeth. Camshaft
and crankshaft timing should be checked. Refer to
Group 9, Engine Timing belt or chain installation.
It is important that the vehicle is operating to it's
optimum performance level to maintain fuel economy
and lowest vehicle emissions. If vehicle is not operat-ing to these standards, refer to Engine Diagnosis in
this section. The following procedures can assist in
achieving the proper engine diagnosis.
(1) Test cranking amperage draw. Refer to Group
8B, Starting.
(2) Check intake manifold for vacuum leaks.
(3) Perform cylinder compression pressure test.
Refer to Engine Diagnosis in this section.
(4) Clean or replace spark plugs as necessary and
adjust gap as specified in Group 8D, Ignition System.
Tighten to specifications.
(5) Test resistance of spark plug cables. Refer to
Group 8D, Ignition System.
(6) Test ignition coils primary and secondary resis-
tance. Replace parts as necessary. Refer to Group 8D,
Ignition System.
(7) Check fuel pump pressure at idle and different
RPM ranges. Refer to Group 14, Fuel System for
specifications.
(8) The air filter elements should be replaced as
specified in Group 0, Lubrication and Maintenance.
(9) Inspect crankcase ventilation system. Refer to
Group 25, Emission Control Systems.
(10) Road test vehicle as a final test.HONING CYLINDER BORES
(1) Used carefully, the cylinder bore resizing hone,
recommended tool C-823 or equivalent, equipped
with 220 grit stones, is the best tool for this honing
procedure. 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
Fig. 2 Access Plug
1 ± CRANKSHAFT BOLT ACCESS PLUG
2 ± RIGHT MOUNT BOLT ACCESS PLUG
3 ± FASCIA
4 ± SPLASH SHIELD
Fig. 3 Core Hole Plug Removal
1 ± CYLINDER BLOCK
2 ± REMOVE PLUG WITH PLIERS
3 ± STRIKE HERE WITH HAMMER
4 ± DRIFT PUNCH
5 ± CUP PLUG
PLENGINE 9 - 3
GENERAL INFORMATION (Continued)

will clean up a bore and maintain the required lim-
its.
(2) Deglazing of the cylinder walls may be done
using a cylinder surfacing hone, recommended tool
C-3501 or equivalent, equipped with 280 grit stones,
if the cylinder bore is straight and round. 20±60
strokes depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Inspect cyl-
inder walls after each 20 strokes, using a light
honing oil.Do not use engine or transmission oil,
mineral spirits or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a cross-hatch pattern.
When hone marksintersectat 50-60 degrees, the
cross hatch angle is most satisfactory for proper seat-
ing of rings (Fig. 4).
(4) A controlled hone motor speed between
200±300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50±60
degree angle. Faster up and down strokes increase
the cross-hatch angle.
(5) After honing, it is necessary that the block be
cleaned again to remove all traces of abrasive.
CAUTION: Ensure all abrasives are removed from
engine parts after honing. It is recommended that a
solution of soap and hot water be used with a
brush and the parts then thoroughly dried. The bore
can be considered clean when it can be wiped
clean with a white cloth and cloth remains clean.
Oil the bores after cleaning to prevent rusting.MEASURING WITH PLASTIGAGE
PLASTIGAGE METHOD
Engine crankshaft bearing clearances can be deter-
mined by use of Plastigage or equivalent. The follow-
ing is the recommended procedure for the use of
Plastigage:
NOTE: The total clearance of the main bearings can
only be determined by removing the weight of the
crankshaft. This can be accomplished by either of
two methods:
PREFERRED METHOD
Shim the bearings adjacent to the bearing to be
checked in order to remove the clearance between
upper bearing shell and the crankshaft. This can be
accomplished by placing a minimum of 0.254 mm
(0.010 in.) shim (e. g. cardboard, matchbook cover,
etc.) between the bearing shell and the bearing cap
on the adjacent bearings and tightening bolts to
14-20 N´m (10-15 ft. lbs.). The number of main bear-
ing will vary from engine to engine.
ENGINE WITH 5 MAIN BEARINGS
²When checking #1 main bearing shim #2 main
bearing.
²When checking #2 main bearing shim #1 & 3
main bearing.
²When checking #3 main bearing shim #2 & 4
main bearing.
²When checking #4 main bearing shim #3 & 5
main bearing.
²When checking #5 main bearing shim #4 main
bearing.
ENGINE WITH 4 MAIN BEARING
²When checking #1 main bearing shim # 2 main
bearing.
Fig. 4 Cylinder Bore Cross-Hatch Pattern
1 ± CROSS-HATCH PATTERN
Fig. 5 Plastigage Placed in Lower Shell
1 ± PLASTIGAGE
9 - 4 ENGINEPL
GENERAL INFORMATION (Continued)

²When checking #2 main bearing shim #1 & #3
main bearing.
²When checking #3 main bearing shim #2 & #4
main bearing.
²When checking #4 main bearing shim #3 main
bearing.
NOTE: REMOVE ALL SHIMS BEFORE REASSEM-
BLING ENGINE
ALTERNATIVE METHOD
The weight of the crankshaft can be supported by a
jack under the counterweight adjacent to the bearing
being checked.
PLASTIGAGE PROCEDURE
(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 shell in the cap approximately
6.35 mm (1/4 in.) off center and away from the oil
holes (Fig. 5). (In addition, suspected areas can be
checked by placing the Plastigage in the suspected
area). Torque the bearing cap bolts of the bearing
being checked to the proper specifications.
(3) Remove the bearing cap and compare the width
of the flattened Plastigage (Fig. 6) with the metric
scale provided on the package. Locate the band clos-
est to the same width. This band shows the amount
of clearance in thousandths of a millimeter. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Refer to Engine Specifications.Plastigage gener-
ally is accompanied by two scales. One scale is
in inches, the other is a metric scale.
NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
CONNECTING ROD BEARING CLEARANCE
Engine connecting rod bearing clearances can be
determined by use of Plastigage or equivalent. Thefollowing is the recommended procedure for the use
of Plastigage:
(1) Rotate the crankshaft until the connecting rod
to be checked is at the bottom of its stroke.
(2) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(3) Place a piece of Plastigage across the entire
width of the bearing shell in the bearing cap approx-
imately 6.35 mm (1/4 in.) off center and away from
the oil hole (Fig. 5). In addition, suspect areas can be
checked by placing plastigage in that area.
(4) Assemble the rod cap with Plastigage in place.
Tighten the rod cap to the specified torque.Do not
rotate the crankshaft while assembling the cap
or the Plastigage may be smeared, giving inac-
curate results.
(5) Remove the bearing cap and compare the width
of the flattened Plastigage (Fig. 6) with the scale pro-
vided on the package. Locate the band closest to the
same width. This band indicates the amount of oil
clearance. Differences in readings between the ends
indicate the amount of taper present. Record all
readings taken. Refer to Engine Specifications.Plas-
tigage generally is accompanied by two scales.
One scale is in inches, the other is a metric
scale. If the bearing clearance exceeds wear
limit specification, replace the bearing.
REPAIR OF DAMAGED OR WORN THREADS
Damaged or worn threads (including aluminum
head spark plug threads) can be repaired. Essen-
tially, this repair consists of drilling out worn or
damaged threads, tapping the hole with a special
Heli-Coil Tap, (or equivalent) and installing 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 centerline.
Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
HYDROSTATIC LOCKED ENGINE
When an engine is suspected to be hydrostatically
locked, regardless of what caused the problem, the
following steps should be used.
CAUTION: DO NOT use starter motor to rotate the
engine, severe damage may occur.
(1) Inspect air cleaner, induction system and
intake manifold to insure system is dry and clear of
foreign material.
(2) Remove negative battery cable.
(3) Place a shop towel around the spark plugs
when removing them from the engine. This will catch
Fig. 6 Clearance Measurement
PLENGINE 9 - 5
GENERAL INFORMATION (Continued)

any fluid that may possibly be in the cylinder under
pressure.
(4) With all spark plugs removed, rotate engine
crankshaft using a breaker bar and socket.
(5) Identify the fluid in the cylinder(s) (i.e., cool-
ant, fuel, oil or other).
(6) Make sure all fluid has been removed from the
cylinders. Inspect engine for damage (i.e., connecting
rods, pistons, valves, etc.).
(7) Repair engine or components as necessary to
prevent this problem from re-occurring.
CAUTION: Squirt approximately one teaspoon of oil
into the cylinders, rotate engine to lubricate the cyl-
inder walls to prevent damage on restart.
(8) Install new spark plugs.
(9) Drain engine oil and remove oil filter.
(10) Fill engine with specified amount of approved
oil and install new oil filter.
(11) Connect negative battery cable.
(12) Start engine and check for any leaks.
CHECKING ENGINE OIL LEVEL
The best time to check engine oil level is after it
has sat overnight, or if the engine has been running,allow the engine to be shut off for at least 5 minutes
before checking oil level.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
reading. Remove dipstick (Fig. 7) and observe oil
level. Add oil only when the level is at or below the
ADD mark (Fig. 8).
Fig. 7 Dipstick and Engine Oil Fill Locations
1 ± ENGINE OIL FILL
2 ± ENGINE COOLANT RECOVERY CONTAINER3 ± ENGINE OIL DIPSTICK
4 ± COOLING SYSTEM PRESSURE CAP
Fig. 8 Oil Level
1 ± ENGINE OIL LEVEL DIPSTICK
9 - 6 ENGINEPL
GENERAL INFORMATION (Continued)

ENGINE DIAGNOSIS
TABLE OF CONTENTS
page page
DIAGNOSIS AND TESTING
GENERAL INFORMATION...................8
INTAKE MANIFOLD LEAKAGE DIAGNOSIS......8
CYLINDER COMPRESSION PRESSURE TEST . . . 8
CYLINDER COMBUSTION PRESSURE
LEAKAGE TEST.........................9LASH ADJUSTER (TAPPET) NOISE
DIAGNOSIS............................9
ENGINE OIL LEAK INSPECTION..............9
ENGINE DIAGNOSISÐPERFORMANCE........11
ENGINE DIAGNOSISÐMECHANICAL.........12
DIAGNOSIS AND TESTING
GENERAL INFORMATION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
Refer to the Service DiagnosisÐMechanical Chart
and the Service DiagnosisÐPerformance Chart, for
possible causes and corrections of malfunctions. Refer
to Group 14, Fuel System, for the fuel system diag-
nosis.
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
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
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.
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) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Disconnect coil wire from distributor and
secure to good ground to prevent a spark from start-
ing a fire (Conventional Ignition System). For Direct
Ignition System DIS disconnect the coil connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor into the #1
spark plug hole in cylinder head. Crank engine until
maximum pressure is reached on gage. Record this
pressure as #1 cylinder pressure.
(7) Repeat the previous step for all remaining cyl-
inders.
(8) Compression should not be less than (689 kPa)
100 psi and not vary more than 25 percent from cyl-
inder to cylinder.
(9) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(10) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
9 - 8 ENGINEPL