1999 DODGE NEON spark plugs replace

cause of low compression unless some malfunc-
tion is present.
(11) Clean or replace spark plugs as necessary
and adjust gap as specified in Group 8, Electrical.
Tighten to specifications.
(12) Test resistance of spark plug cables. Refer to
Group 8, Electrical Ignition System Secondary Cir-
cuit Inspection.
(13) Test coil output voltage, primary and second-
ary resistance. Replace parts as necessary. Refer to
Group 8, Electrical Ignition System.
(14) Check fuel pump pressure at idle and differ-
ent RPM ranges. Refer to Group 14, Fuel System for
Specifications.
(15) The air filter elements should be replaced as
specified in Group 0, Lubrication and Maintenance,.
(16) Inspect crankcase ventilation system as out
lined in Group 0, Lubrication and Maintenance. For
emission controls see Group 25, Emission Controls
for service procedures.
(17) Inspect and adjust accessory belt drives refer-
ring to Group 7, Cooling System, Accessory Drive
Belts for proper adjustments.
(18) Road test vehicle as a final test.
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.
Clean spark plug recesses with compressed air.
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
according 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.
LASH ADJUSTER (TAPPET) NOISE DIAGNOSIS
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) During this time, 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 pressed into the vertical 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) Faulty lash adjuster.
a. Check lash adjusters for sponginess while
installed in cylinder head. Depress part of rocker
arm over adjuster. Normal adjusters should feel very
firm. Spongy adjusters can be bottomed out easily.
b. Remove suspected rocker arms (sohc) or lash
adjuster (dohc) and replace.
INSPECTION (ENGINE OIL LEAKS IN GENERAL)
Begin with a through visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following 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
approximately 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.
9 - 8 ENGINEPL
DIAGNOSIS AND TESTING (Continued)

ENGINE DIAGNOSISÐPERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT
START1. Weak battery. 1. Test battery. Charge or replace as necessary.
Refer to Group 8A, Battery.
2. Corroded or loose battery connections. 2. Clean and tighten battery connections. Apply a
coat of light mineral grease to terminals.
3. Faulty starter. Test starting system. Refer to Group 8B, Starting.
4. Moisture on ignition wires. 4. Remove moisture from wires.
5. Faulty ignition cables. 5. Replace any cracked or shorted cables.
6. Faulty coil or control unit. 6. Test and replace as needed. Refer to Group 8D,
Ignition System
7. Incorrect spark plug gap. 7. Set gap. Refer to Group 8D, Ignition System.
8. Contamination in fuel system. 8. Clean system and replace fuel filter.
9. Faulty fuel pump. 9. Test fuel pump and replace as needed. Refer to
Group 14, Fuel System.
ENGINE STALLS OR
IDLES ROUGH1. Idle speed too low. 1. Test minimum air flow. Refer to Group 14, Fuel
System.
2. Incorrect fuel mixture. 2. Refer to Group 14, Fuel System.
3. Intake manifold leakage. 3. Inspect intake manifold, manifold gasket, and
vacuum hoses. Refer to Group 11, Exhaust System
and Intake Manifold.
4. Incorrect ignition wiring. 4. Install correct wiring.
5. Faulty coil(s) 5. Test and replace as necessary. Refer to Group
8D, Ignition System.
ENGINE LOSS OF
POWER1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap. Refer to Group 8D,
Ignition System.
2. Contamination in fuel system. 2. Clean system and replace fuel filter.
3. Faulty fuel pump. 3. Test and replace as necessary. Refer to Group
14, Fuel System.
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust system. 8. Install new parts, as necessary.
9. Faulty ignition cables. 9. Replace any cracked or shorted cables.
10. Faulty coil(s). 10. Test and replace as necessary. Refer to Group
8D, Ignition System.
ENGINE MISSES ON
ACCELERATION1. Dirty or incorrectly gapped spark plugs. 1. Clean spark plugs and set gap. Refer to Group
8D, Ignition System.
2. Contamination in Fuel System. 2. Clean fuel system and replace fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty coil(s). 4. Test and replace as necessary. Refer to Group
8D, Ignition System.
ENGINE MISSES AT
HIGH SPEED1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap. Refer to Group
8D, Ignition System.
2. Faulty coil(s). 2. Test and replace as necessary. Refer to Group
8D, Ignition System.
3. Dirty fuel injector(s). Test and replace as necessary. Refer to Group 14,
Fuel System.
4. Contamination in fuel system. 4. Clean system and replace fuel filter.
9 - 10 ENGINEPL
DIAGNOSIS AND TESTING (Continued)

ENGINE DIAGNOSISÐMECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level in crankcase. 1. Check for correct oil level.
2. Thin or diluted oil. 2. Change oil to correct viscosity.
3. Low oil pressure. 3. Check engine oil level.
4. Dirt in tappets/lash adjusters. 4. Replace rocker arm/hydraulic lash adjuster
assembly.
5. Worn rocker arms. 5. Inspect oil supply to rocker arms.
6. Worn tappets/lash adjusters. 6. Install new rocker arm/hydraulic lash adjuster
assembly.
7. Worn valve guides. 7. Ream and install new valves with oversize
stems.
8. Excessive runout of valve seats on valve faces. 8. Grind valve seats and valves.
9. Missing adjuster pivot. 9. Replace rocker arm/hydraulic lash adjuster
assembly.
CONNECTING ROD
NOISE1. Insuffient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil pump relief
valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Excessive bearing clearance. 4. Measure bearings for correct clearance. Repair
as necessary.
5. Connecting rod journal out-of-round. 5. Replace crankshaft or grind surface.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil pump relief
valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Excessive bearing clearance. 4. Measure bearings for correct clearance. Repair
as necessary.
5. Excessive end play. 5. Check thrust bearing for wear on flanges.
6. Crankshaft journal out-of-round or worn. 6. Replace crankshaft or grind journals.
7. Loose flywheel or torque converter. 7. Tighten to correct torque.
OIL PRESSURE DROP 1. Low oil level. 1. Check engine oil level.
2. Faulty oil pressure sending unit. 2. Install new sending unit.
3. Low oil pressure. 3. Check sending unit and main bearing oil
clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Excessive bearing clearance. 7. Measure bearings for correct clearance.
8. Oil pump relief valve stuck. 8. Remove valve and inspect, clean, or replace.
9. Oil pump suction tube loose. 9. Remove oil pan and install new tube or clean, if
necessary.
10. Oil pump cover warped or cracked. 10. Install new oil pump.
OIL LEAKS 1. Misaligned or deteriorated gaskets. 1. Replace gasket(s).
2. Loose fastener, broken or porous metal part. 2. Tighten, repair or replace the part.
3. Misaligned or deteriorated cup or threaded plug. 3. Replace as necessary.
OIL CONSUMPTION
OR SPARK PLUGS
FOULED1. PCV system malfunction. 1. Check system and repair as necessary. Refer to
Group 25, Emission Control Systems.
2. Worn, scuffed or broken rings. 2. Hone cyinder bores. Install new rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check grooves. If groove is
not proper width, replace piston.
5. Worn valve guides. 5. Ream guides and replace valves with oversize
valves and seals.
6. Valve stem seal unseated or faulty. 6. Repair or replace seal.
PLENGINE 9 - 11
DIAGNOSIS AND TESTING (Continued)

The exhaust ball joint consists of two bolts, two
springs, and a ball joint seal ring, which is a sepa-
rate part from the exhaust pipe.
EXHAUST FLEX-JOINT COUPLING (LEV)
An exhaust flex-joint coupling is used on Low
Emission Vehicles (LEV) (Fig. 3). This coupling is
used to secure the catalytic converter to the exhaust
manifold. This coupling actually moves back and
forth as the engine moves, preventing breakage that
could occur from the back and forth motion of a
transverse mounted engine.
The exhaust flex-joint is welded to the catalytic
converter.
CATALYTIC CONVERTER
There is no regularly scheduled maintenance on
any Chrysler catalytic converter (Fig. 4). If damaged,
the converter must be replaced.
CAUTION: Due to exterior physical similarities of
some catalytic converters with pipe assemblies,
extreme care should be taken with replacement
parts.
The combustion reaction caused by the catalyst
releases additional heat in the exhaust system. Caus-
ing temperature increases in the area of the reactor
under severe operating conditions. Such conditions
can exist when the engine misfires or otherwise does
not operate at peak efficiency.Do notremove spark
plug wires from plugs or by any other means short
out cylinders if exhaust system is equipped with a
catalytic converter. Failure of the catalytic converter
can occur due to temperature increases caused by
unburned fuel passing through the converter.
The use of the catalysts also involves some non-au-
tomotive problems. Unleaded gasoline must be used
to avoid poisoning the catalyst core. Do not allow
engine to operate above 1200 RPM in neutral for
extended periods over 5 minutes. This condition may
result in excessive exhaust system/floor pan temper-
atures because of no air movement under the vehicle.
Fig. 2 Ball Joint Connection
Fig. 3 Flex-Joint (LEV)
Fig. 4 Exhaust System ComponentsÐTypical
11 - 2 EXHAUST SYSTEM AND INTAKE MANIFOLDPL
GENERAL INFORMATION (Continued)

(10) Inspect the electrical and hose connections at
the duty cycle purge solenoid (Fig. 39).(11) Check the electrical connection to the radiator
fan.
(12) Inspect for corrosion on the electrical connec-
tions at the starter motor solenoid. Check the ground
cable connection below the starter motor (Fig. 40).
(13) Inspect the air cleaner filter element. Replace
as necessary. Check the air induction system for
restrictions.
Fig. 35 PCV Valve
Fig. 36 MAP/Intake Air Temperature Sensor
Fig. 37 Fuel Injectors
Fig. 38 Ignition Coil and Spark PlugsÐTypical
PLFUEL SYSTEM 14 - 37
DIAGNOSIS AND TESTING (Continued)