DODGE TRUCK 1993 Service Repair Manual

9
- 6
ENGINES
•

SERVICE DIAGNOSIS (GASOLINE ENGINES)
•
PERFORMANCE (CONT.)

1
CONDITION

POSSIBLE
CAUSES
^
CORRECTION

1
ENGINE
LOSS
OF
POWER
1.
Incorrect ignition timing.
2. Worn or burned distributor
rotor.
3. Worn distributor shaft.

4.
Dirty
or
incorrectly
gapped
spark
plugs.

5.
Dirt
or
water
in
fuel
system.

6.
Faulty
fuel
pump.

7.
Incorrect valve timing.
8.
Blown
cylinder head
gasket.

9.
Low
compression.

10.
Burned,
warped or
pitted
valves.

11.
Plugged
or
restricted
exhaust
system.

12. Faulty ignition
cables.

13. Faulty coil.
1.
Refer
to
Group
8D, Ignition
System.

2. install new distributor
rotor.

3.
Remove
and
repair
distributor
(refer
to
Group
8D, Ignition
System).

4.
Clean
plugs
and
set gap
(refer
to
Group
8D, Ignition
System).

5. Clean
system
and replace
fuel
filter.

6. Install new
fuel
pump.

7.
Correct
valve
timing.
8. Install new cylinder head
gasket.

9.
Test
compression
of
each
cylinder.

10.
Install new
valves.
11.
Install new
parts,
as
necessary.

12.
Replace
any cracked or
shorted
cables.

13.
Test
and
replace,
as
necessary
(refer
to
Group
8D, Ignition
System).

ENGINE
MISSES
ON

ACCELERATION
1.
Dirty
or
gap set
too
wide
in spark
plug.
2. Incorrect ignition timing.
3.
Dirt
in
fuel
system.

4.
Burned,
warped or
pitted
valves.
5. Faulty coil.
1.
Clean spark
plugs
and set gap
(refer
to
Group
8D, Ignition

System).

2. Refer to
Group
8D, Ignition
System.

3. Clean
fuel
system.

4.
Install new
valves.

5.
Test
and
replace,
if
necessary,
(refer
to
Group
8D, Ignition
System).

ENGINE
MISSES
AT HIGH

SPEED
1.
Dirty
or
gap set too
wide
in spark
plug.
2. Worn distributor shaft.
3. Worn or burned distributor
rotor.

4. Faulty
coil.

5. Incorrect ignition timing.
6.
Dirty
injector
in
throttle
body.
7.
Dirt
or
water
in
fuel
system.
1.
Clean
spark
plugs
and
set gap
(refer
to
Group
8D, Ignition

System).

2.
Remove
and
repair
distributor
(refer
to
Group
8D,
Ignition
System).

3. Install new distributor
rotor.

4.
Test
and replace,
as
necessary
(refer
to
Group
8D, Ignition
System).

5.
Refer
to
Group
8D, Ignition
System.

6.
Clean
injector.

7.
Clean
system
and replace
fuel
filter.

J9309-106

•

ENGINES
9 - 7 SERVICE DIAGNOSIS (GASOLINE ENGINES) - MECHANICAL

CONDITION
PSSSI1LI
CAUSIS
CORRECTION

NOISY
VALVES
1. High
or
low oil
level
in

crankcase.

2. Thin or
diluted
oil.

3.
Low
oil
pressure.
4.
Dirt
in
tappets/lash
adjusters.

5. Bent
push
rods.
6. Worn rocker arms.
7.
Worn
tappets/lash
adjusters.

8.
Worn
valve
guides.

9.
Excessive
runout
of
valve
seats
on
valve
faces.
1.
Check
for
correct oil
level
(refer
to
Group
0,
Lubrication and
Maintenance).
2. Change oil
(refer
to Group
0,
Lubrication and Maintenance).
3. Check engine oil level.
4. Clean hydraulic tappets/hydraulic lash adjusters.
5. Install new
push
rods.
6. Inspect oil supply to rocker arms.
7. Install new hydraulic tappets/hydraulic lash adjusters. 8. Ream and install new valves
with
oversize stems.
9. Grind valve seats and valves.

CONNECTING
ROD
NOISE
1.
Insufficient oil supply.

2.
Low oil
pressure.

3.
Thin
or
diluted
oil.
4.
Excessive
bearing
clearance.
5. Connecting rod
journal
out-of- round.
6. Misaligned connecting rods.
1.
Check engine oil
level
(refer
to Group
0,
Lubrication and
Maintenance).
2. Check engine oil level. Inspect oil pump
relief
valve and spring.
3. Change oil to correct
viscosity.

4. Measure bearings for correct clearance. Repair as necessary, 5. Replace crankshaft or grind journals.

6.
Replace
bent
connecting rods.

MAIN
BEARING
NOISE
1.
Insufficient oil supply.
2 Low
oil
pressure.
3. Thin or
diluted
oil.
4.
Excessive
bearing clearance. 5.
Excessive
end play.
6. Crankshaft
journal
out-of-round, worn,
7.
Loose
flywheel
or
torque

converter.
1.
Check engine oil
level
(refer
to Group
0,
Lubrication and
Maintenance).
2. Check engine oil level. Inspect oil pump
relief
valve and spring.
3. Change oil to correct
viscosity.

4. Measure bearings for correct clearance. Repair as necessary. 5. Check No.
3
main bearing for
wear
on flanges.
6. Grind journals
or
replace crankshaft.
7. Tighten to correct torque.

OIL
PRESSURE
DROP
1.
Low oil level.
2. Faulty oil pressure sending
unit.

3. Low
oil
pressure.
4.
Clogged
oil
filter.

5 Worn parts in
oil
pump.
6. Thin or
diluted
oil.
7.
Excessive
bearing clearance. 8.
Oil
pump
relief
valve stuck.
9. Oil pump suction
tube
loose,
bent
or cracked.

10.
Oil pump cover warped
or
cracked.
1.
Check engine oil level.
2. Install new sending
unit.

3. Check sending
unit
and check main bearing oil clearance.
4. Install new oil
filter.

5. Replace worn parts or pump. 6. Change oil to correct
viscosity.

7. Measure bearings for correct clearance.
8. Remove valve and inspect, clean and install. 9. Remove oil pan and install new tube,
if
necessary.
10. Install new oil pump.

OIL
LEAKS
1.
Misaligned or
deteriorated

gaskets.
2.
Loose
fastener, broken
or
porous
metal
part.
1. Replace the gasket.
2. Tighten,
repair
or replace the
part.

OIL
PUMPING
AT
RINGS;
SPARK
PLUGS
FOULING
1.
Worn, scuffed
or broken
rings.
2. Carbon in oil ring
slot.

3.
Rings
fitted
too
tightly
in grooves.
4. Worn valve guides.
5. Leaking
intake
gasket.
6. Leaking valve guide
seals.

7. Dislodged valve guide
seals.
1.
Hone cylinder bores and install new rings.
2. Install new rings.
3. Remove the rings. Check
grooves.
If
grooves
are not proper width, replace piston.
4. Ream guides and replace valves
with
oversize valves and
seals.

5. Replace gasket and tighten
intake
manifold
to
proper torque.
6. Replace
seals.

7. Seat
valve guide
seals
or
replace, as needed.
J9209-58

9
- 8
ENGINES

• SERVICE DIAGNOSIS (DIESEL ENGINE) - PERFORMANCE

CONDITION
POSSIBLE
CAUSES
COtiECTION

ENGINE
WILL
NOT

CRANK
OR
CRANKS

SLOWLY
Starting
motor operating, but
not cranking the engine.

Crankshaft
rotation restricted.

Starting
circuit
connections
loose
or corroded.
Neutral safety switch or starter
relay inoperative.
Battery charge low.

No
voltage to starter
solenoid.

Solenoid
or starting motor inoperative.
Remove
the starter motor. Check for broken flywheel
teeth
or

a
broken starting motor
spring.

Rotate the engine to check for rotational resistance.

Clean
and tighten
connections.

Check
starter relay for
supply
voltage and proper operation of neutral safety. Replace defective parts.

Check
battery voltage. Replace battery if a charge cannot be
held.

Check
voltage to
solenoid.
If
necessary,
replace the
solenoid.

Replace
starter motor.

ENGINE
CRANKS,

BUT
WILL
NOT

START—NO
SMOKE
FROM
EXHAUST
No
fuel
in supply tank.
Electrical
fuel
shutdown not

open.

Air
intake or exhaust
plugged.

Fuel
filter
plugged.

Injection pump not getting
fuel

or
fuel
is aerated.

Worn
or inoperative injection
pump.

Internal pump timing incorrect.

Camshaft
out of time.
Fill
fuel
supply.

Check
for
loose
wires and verify that the valve is functioning.
Check
to be sure manual shutoff lever is in the run position.

Remove
the obstruction.

Drain
fuel/water separator and replace
fuel
filter.

Check
fuel
flow/bleed
fuel
system.

Visually
check
fuel
delivery with an externally connected injector to one of the pump outlets. Replace the pump if
fuel

is
not being delivered.
Time the pump
(refer
to Group 14, Fuel
System).

Check/correct
gear train timing alignment.

ENGINE
HARD
TO

START,
OR
WILL
NOT
START—SMOKE

FROM
EXHAUST
Incorrect starting procedure.

Cranking
speed too
slow.

Cold
starting
aids
not working

or
are needed.
Intake heater
system
not

working.

Insufficient intake air.

Air
in the
fuel
system
or the

fuel
supply is inadequate. The manual
fuel
shutoff control must be in the run position.
(a) Verify that the
transmission
is not
engaged.

(b) Check the battery, starting motor and look for
loose
or

corroded
wiring
connections.

(c) Rotate the engine with a barring tool
(Snap-On
Tool
SP371,
MTE
No. 3377462, or equivalent) to check for internal rotational resistance.
Verify the
aids
are operating. Repair/replace inoperative
parts.

Verify
system
is working. Repair/replace inoperative parts.

Inspect
or replace
filter
and check for
obstructions
to the air

supply
tube.

Check
the flow through the
filter
and bleed the
system.
Locate

and
eliminate the air source. J9109-232

•

ENGINES
9 - 9 SERVICE DIAGNOSIS (DIESEL ENGINE) • PERFORMANCE (CONT.)

CONDITION
POSSIBLE
CAUSES
CORRECTION

ENGINE
HARD
TO

START,
OR
WILL

NOT
START—SMOKE

FROM
EXHAUST

(Cont'd)
Fuel pump Inoperative.
Injection pump
throttle
linkage

loose
or
damaged.

Contaminated
fuel.

Worn
or inoperative injection
pump.

Injection pump out of time.

Valves
incorrectly adjusted.

One
or more injectors worn or not operating properly.
Disconnect
fuel
line and verify
fuel
delivery. If needed replace

pump.

Visually
check the linkage. Tighten/replace linkage.
Verify by operating the engine with clean
fuel
from a temporary tank. Check for presence of
gasoline.
Drain and

flush
fuel
supply tanks.
Replace
fuel/water separator
filter.

Visually
check
fuel
delivery with an externally connected injector to one of the pump outlets. Replace the pump if
fuel
is
not being delivered.

Check/time
the pump
(refer
to Group 14, Fuel
System).

Adjust
valves.
Check/replace
bad improperly operating injectors.

ENGINE
STARTS,

BUT
WILL
NOT

KEEP
RUNNING
Idle speed too low for the

accessories.

Intake air or exhaust
system

restricted.

Air
in the
fuel
system
or the

fuel
supply is inadequate.
Fuel waxing due to extremely

cold
weather.

Contaminated
fuel.
Adjust
the idle
speed.

Visually
check for exhaust restriction and inspect the air intake.
Repair/replace restricting parts.

Check
the flow through the
filter
and bleed the
system.
Locate

and
eliminate the air source.
Verify by inspecting the
fuel
filter.
Clean the
system
and use
climatized fuel. Replace fuel/water separator
filter.
Check
fuel

heater for proper operation.
Verify by operating the engine with clean
fuel
from a temporary

supply
tank. Check for presence of
gasoline.
Replace fuel/water

separator
filter.

SURGING
(SPEED

CHANGE)
If the condition
occurs
at idle,
the idle speed is set too low for
the
accessories.

High
pressure
fuel
leak.

One
or more injectors worn or not operating properly.
Improperly operating injection

pump.
Adjust
the idle.

Inspect/correct
leaks in the high pressure lines. Fittings and
delivery valve
sealing
washers.

Check/replace
the inoperative injectors.

Replace
the injection pump.

ROUGH
IDLE

(IRREGULARLY
FIRING

OR
ENGINE
SHAKING)
Cold
engine.
Idle speed too low for the

accessories.

Engine
mounts
damaged
or
loose.
Refer to troubleshooting
logic
for intake manifold heater
system

(see
Group 11,
Exhaust
System
& Intake Manifold)

Adjust
idle
speed.

Repair
or replace mounts. J9109-233

9
- 10
ENGINES
— _
•
CONDITION

possmu
CLOSES
CORRECTION

ROUGH
IDLE

(IRREGULARLY
FIRING

OR
ENGINE
SHAKING)
(Cont'd)
High
pressure
fuel
leaks.

Air In the
fuel
system.
Correct leaks in the high pressure lines, fittings or
delivery

valves.

Bleed the
fuel
system and
eliminate
the source of the air.

Sticking
needle
valve
in an
injector.
Check and replace the
injector
with
the sticking
needle
valve.

ENGINE
RUNS
ROUGH

OR
MISFIRING
Fuel
injection
lines
leaking.

Correct leaks in the high pressure lines, fittings,
injector
sealing

washers
or
delivery
valves.
Air in the
fuel
or the
fuel
supply
is
inadequate.
Check the flow through the
filter
and bleed the system. Locate
and
eliminate
the air source.

Contaminated
fuel.
Verify
by operating the engine
with
clean
fuel
from a temporary

supply
tank. Check for presence of gasoline. Replace
fuel/water

separator
filter.

Incorrect
valve
adjustment.
Check for a
bent
push rod and adjust valves. Replace push rod,
if necessary.

Injection
pump
timing
incorrect.
Check/time pump
(refer
to Group 14,
Fuel
System).

Improperly
operating
injectors.
Replace inoperative injectors.
Defective
injection
pump

(delivery
valves).
Replace
injection
pump.

Camshaft
out of
time.
Check/correct gear
train
timing alignment.

Damaged
camshaft or
tappets.
Inspect camshaft valve
lift.
Replace camshaft and tappets.

ENGINE
RPM WILL NOT

REACH
RATED
SPEED
Engine
overloaded.

Verify
high
idle
speed
without
load. Investigate operation to be
sure correct gear is being used.

Improperly
operating
tachometer.
Verify
engine speed
with
hand tachometer—correct as required.

Throttle
linkage
worn
or
incorrectly
adjusted.
Adjust linkage for stop-to-stop
fuel
control
lever
travel.
Replace
linkage if necessary.
Partially
engaged
mechanical

shutdown
lever.
Adjust and place shutdown
lever
in the run position.

Inadequate
fuel
supply. Check the
fuel
flow through the system to locate the reason for
inadequate
fuel
supply—correct as required.

Improperly
operating
injection

pump.
Replace
injection
pump.

LOW
POWER
Fuel
control
lever
not
moving
to

full
throttle.
Check/correct for stop-to-stop
travel.

Mechanical/shutdown
lever
partially
engaged.
Check to see if the shutdown
lever
is in run position.

High
oil
level.
Check/correct oil level.

Engine
overloaded.
Check for added loading from accessories or driven units, brakes

dragging
and
other
changes in vehicle loading. Repair/replace as
needed.
J9109-264
SERVICE
DIAGNOSIS (DIESEL ENGINE)
•
PERFORMANCE (CONT.)

•

ENGINES
9 - 11 SERVICE DIAGNOSIS (DIESEL ENGINE) - PERFORMANCE (CONT.)

CONDITION
POSSIBLE
CAUSES
CORRECTION

LOW
POWER
(Cont'd)
SJow
throttle
response, leaking
air
fuel
control
tube
or
improperly
operating
control

in the pump. Tighten the fittings. Replace the pump if the controls are not
functioning.
Incorrect
external
injection

pump
timing. Verify
that
injection pump timing marks are aligned (see Group
14, Fuel System).
Inadequate intake air flow. Inspect/replace air cleaner element. Look for other restrictions.

High
pressure
fuel
leak. Inspect/correct leaks in the high pressure lines, fittings
injector

sealing
washers or delivery valve
seals.

Inadequate
fuel
supply.
Check
the flow through the
filter
to locate the source of the
restriction.

High
fuel
temperature. Verify
that
fuel
heater is off during warm weather. Check for a
restricted
fuel
drain manifold. Repair/replace as needed.

Poor
quality
fuel
or
fuel

contaminated
with
gasoline. Verify by operating from a temporary tank
with
good
fuel.

Check
for presence of
gasoline.
Replace
fuel/water
separator

filter.

Air
leak between the turbo- charger and the intake manifold. Check/correct leaks in the air crossover tube,
hoses,
gaskets,

and
around mounting capscrews or through holes in the manifold
cover.

Exhaust
leak at the manifold
or turbocharger. Check/correct leaks in the manifold or turbocharger
gaskets.

If manifold is cracked, replace manifold.
Improperly operating turbo-
charger. Inspect/replace turbocharger.
Valve clearance incorrect.
Check/adjust
valves.
Injection pump improperly
operating. Check/time pump
(refer
to Group 14, Fuel System).

Worn
or improperly operating injectors. Check/replace injectors.
Improperly operating injection

pump.
Replace
injection pump.

Excessive
exhaust restriction. Check/correct the restriction in the exhaust system.

EXCESSIVE
EXHAUST

SMOKE
Engine
running too cold
(white

smoke).
Refer to troubleshooting logic for coolant
temperature
below
normal
(refer
to Group 7,
Cooling
System).
Inspect intake
manifold heater/KSB valve for proper operation.
Inadequate intake air.
Inspect/change
air cleaner. Look for other restriction.

Air
leak between turbocharger

and
intake manifold. Check/correct leaks in the air crossover tube,
hoses,
gaskets,

mounting capscrews or through holes in the manifold cover.

Exhaust
leak at the manifold
or turbocharger. Check/correct leaks in the manifold or turbocharger
gaskets.

If cracked replace manifold.
Improperly operating
turbocharger. Inspect/replace turbocharger.
J9209-57

9
- 12
ENGINES

•
CONDITION

POSSIBLE
CAUSES
CORRECTION

EXCESSIVE
EXHAUST

SMOKE
(Cont'd)
More
than
one
sealing washer
under an injector.
Check
and remove
extra
washer.
Improperly operating injectors.
Check
and replace inoperative injectors.
Improperly operating or over-
fueled injection pump.
Replace
injection pump.

Piston
rings
not sealing
(blue smoke). Perform blow-by check. Correct as required.

ENGINE
WILL
NOT

SHUT-OFF
Fuel shutoff valve inoperative.

Engine
running on fumes drawn into the air intake.
Stop
the engine mechanically
with
lever on the
fuel
pump.

Check/replace
sealing washer, piston and
spring.

Check
the air intake ducts for the source of the fumes.
WARNING:
In
ease
of engine runaway due to flammable
fumes

from gasoline spills or turbocharger oil leaks
being
sucked
into the
engine,
shut off engine ignition switch first then use a CO* or dry
chemical type
fire
extinguisher
and direct the
spray
under
the
front
bumper to
remove
oxygen
supply. The engine air
intake
is on the

passenger
side
behind the bumper. The
fire
extinguisher
must
bo
directed at this location for emergency shutdown conditions.

COOLANT
TEMPERA­

TURE
ABOVE
NORMAL
Low
coolant level.
(a) Check coolant level. Add coolant, if necessary.
(b) Locate and correct the source of the coolant leak. Refer to
troubleshooting
logic for coolant
loss.

Incorrect/improperly operating

pressure
cap.
Replace
cap
with
the correct rating for the
system.

High
lube oil level.
Check/drain
oil to correct level.

Loose
drive belt on water

pump/fan.
Check/replace
belt or belt tensioner.
Inadequate air flow to the radiator. Check/repair radiator core, fan shroud and fan clutch as
required.

Radiator
fins
plugged.
Blow
debris from fins.

Collapsed
radiator
hose.
Replace
the
hose.

Improperly operating tempera­

ture
sensor/gauge.
Verify
that
the
gauge
and temperature
sensor
are accurate.

Replace
gauge/sensor,
if bad.
Improperly operating, incorrect

or
no thermostat.
Check
and replace the thermostat.

Air
in the cooling
system.
(a) Make sure the
fill
rate
is not being exceeded and the correct
vented thermostat is installed.
(b) Check for loose hose
clamps.
Tighten if
loose.

(c) If aeration continued, check for a
compression
leak through the head gasket.
Inoperative water pump.
Check
and replace the water pump.
incorrect injection pump timing. Verify pump timing marks are aligned. Check/time the injector

pump
(refer
to Group 7,
Cooling
System).
J9209-56
SERVICE DIAGNOSIS (DIESEL ENGINE) - PERFORMANCE (CONT.)

•

ENGINES
9 - 13

CONDITION
POSSIBLE
CAUSES
COfiiiECTION

COOLANT
TEMPERA­

TURE
ABOVE
NORMAL
(Cont'd)
Overfueled injection pump.

Plugged
cooling
passages
in
radiator, head, head gasket or

block.

Engine
overloaded.
Replace
the injection
pump.

Flush
the
system
and
fill
with
clean coolant.
Verify
that
the engine load rating is not being exceeded.

COOLANT
TEMPERA­

TURE
BELOW
NORMAL
Too
much air flow
across
the
radiator.
Incorrect thermostat, broken
thermostat jiggle pin or

contamination
in thermostat.
Temperature
sensor
or
gauge
inoperative.

Coolant
not flowing by
temperature
sensor.
Check/repair
viscous
fan as required.

Check
and replace thermostat.
Verify
that
the
gauge
and
sensor
are accurate. If not, replace

gauge/sensor.

Check
and clean coolant
passages.

J9109-254
SERVICE DIAGNOSIS (DIESEL ENGINE) • PERFORMANCE (CONT.)

9
- 14
ENGINES
— — — •

SERVICE
DIAGNOSIS (DIESEL ENGINE)
•
MECHANICAL

CONDITION

r— ———
POSSIBLE
CAUSES
CORRECTION

LUBRICATING
OIL

PRESSURE
LOW Low oil
level.

(a)
Check
and
fill
with
clean engine oil.
(b) Check for a severe
external
oil leak
that
could reduce the pressure.
Oil viscosity thin,
diluted
or wrong specification.
Verify
the correct oil is being
used.
Check for oil dilution. Refer
to Contaminated Lube Oil (Engine Diagnosis—Mechanical).
Improperly operating pressure

switch/gauge.
Verify
the pressure switch is functioning correctly. If not,
replace switch/gauge.
Relief valve stuck open. Check/replace valve.

Plugged
oil
filter.
Change
oil
filter.
Oil
filter
change
interval
may need to be
revised.
If cooler was replaced, shipping

plugs
left
in cooler. Check/remove shipping
plugs.

If pump replaced, four cylinder
oil pump installed in a six
cylinder engine.
Verify
that
the correct pump is installed. If not, install an oil
pump for a six cylinder engine.

Loose
or
missing
cup
plugs.
Check and replace cup
plugs.

Worn oil pump. Check and replace oil pump.

Suction
tube
loose or seal leaking. Check and replace seal.

Loose
main bearing cap. Check and
install
new bearings and tighten cap to proper torque.
Worn bearings or wrong bearings installed. inspect and replace connecting rod or main bearings. Check and
replace piston cooling nozzles.

J9109-237

•
• —
ENGINES
9 - 15
CONDITION

POSSIBLE CAUSES
CORRECTION

LUBRICATING
OIL

PRESSURE
TOO
HIGH
Pressure
switch/gauge
not

operating
properly.
Verify
the
pressure
switch
is
functioning
correctly.
If not,

replace
switch/gauge.

Engine
running
too
cold.
Refer
to
Coolant
Temperature
Below
Normal
(Engine
Diagnosis-

Performance)

Oil
viscosity
too thick. Make
sure
the
correct
oil Is
being
used.
Refer
to
Group
O,

Lubrication
and
Maintenance.

Oil
pressure
regulator
valve

stuck
closed
or
binding.
Check
and replace valve, and/or oil cooler cover.

LUBRICATING
OIL
LOSS
External
leaks.
Visually
inspect for oil
leaks.
Repair as required.

Crankcase
being
overfilled. Verify that the correct dipstick is being
used.

incorrect
oil specification or

viscosity.
(a) Make sure the correct oil is being
used.

(b)
Look
for reduced
viscosity
from dilution with fuel.
(c) Review/reduce the oil
change
intervals.
Oil
cooler
leak.
Check
and replace the oil cooler.

High
blow-by
forcing oil out
the breather.
Check
the breather tube area for
signs
of oil
loss.
Perform the
required repairs.

Turbocharger
leaking
oil to the
air intake.
Inspect
the air
ducts
for evidence of oil transfer.

Repair
as required.

Worn
valve
seals.
Inspect
and replace the valve
seals.

Piston
rings
not
sealing
(oil

being
consumed
by the
engine).
Perform
blow-by check. Repair as required.

COMPRESSION
KNOCKS
Air in the
fuel
system.

Poor
quality
fuel.
Bleed
the fuel
system
(refer
to
Group
14, Fuel
System).

Verify by operating from a temporary tank with
good
fuel. Clean

and
flush the fuel
supply
tanks.
Replace fuel/water separator

filter.

Engine
overloaded. Verify that engine load rating is not being exceeded.
Incorrect injection
pump
timing.
Check
and time injection pump
(refer
to
Group
14, Fuel
System).

Improperly
operating
injectors.
Check
and replace inoperative injectors. J9109-266 SERVICE DIAGNOSIS (DIESEL ENGINE) - MECHANICAL (CONT.)