Chrysler Stratus Convertible. Manual — part 367

ENGINE DIAGNOSIS—PERFORMANCE

CONDITION

POSSIBLE CAUSE

CORRECTION

ENGINE WILL NOT START

1. 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.

3. Test starting system. Refer to
Group 8B, Starting.

4. Faulty coil(s) or control unit.

4. Test and replace as needed.
Refer to Group 8D, Ignition System.

5. Incorrect spark plug gap.

5. Set gap. Refer to Group 8D,
Ignition System.

6. Contamination in fuel system.

6. Clean system and replace fuel
filter.

7. Faulty fuel pump.

7. Test fuel pump and replace as
needed. Refer to Group 14, Fuel
System.

8. Incorrect engine timing.

8. Check for a skipped timing
belt/chain.

ENGINE STALLS OR IDLES
ROUGH

1. 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.

4. Faulty coil(s).

4. Test and replace as necessary.
Refer to Group 8D, Ignition System.

ENGINE LOSS OF POWER

1. 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 coil(s).

9. Test and replace as necessary.
Refer to Group 8D, Ignition System.

JX

ENGINE

9 - 9

DIAGNOSIS AND TESTING (Continued)

CONDITION

POSSIBLE CAUSE

CORRECTION

ENGINE MISSES ON
ACCELERATION

1. 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 SPEED

1. 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.

ENGINE DIAGNOSIS—MECHANICAL

CONDITION

POSSIBLE CAUSES

CORRECTION

NOISY VALVES

1. High or low oil level in
crankcase.

1. Check and correct engine oil
level.

2. Thin or diluted oil.

2. Change oil to correct viscosity.

3. Low oil pressure.

3. Check and correct 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 guides 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 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. Connecting rod journal
out-of-round.

5. Replace crankshaft or grind
surface.

6. Misaligned connecting rods.

6. Replace bent connecting rods.

9 - 10

ENGINE

JX

DIAGNOSIS AND TESTING (Continued)

CONDITION

POSSIBLE CAUSES

CORRECTION

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. Oil pump relief valve stuck.

7. Remove valve and inspect, clean,
or replace.

8. Oil pump suction tube loose.

8. Remove oil pan and install new
tube or clean, if necessary.

9. Oil pump cover warped or
cracked.

9. Install new oil pump.

10. Excessive bearing clearance.

10. Measure bearings for correct
clearance.

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.

JX

ENGINE

9 - 11

DIAGNOSIS AND TESTING (Continued)

CONDITION

POSSIBLE CAUSES

CORRECTION

OIL CONSUMPTION OR SPARK
PLUGS FOULED

1. 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 cylinder 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 guide(s).

5. Ream guide(s) and replace
valve(s) with oversize valve(s) and
seal(s).

6. Valve stem seal(s) worn or
damaged.

6. Replace seal(s).

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
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.

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.

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ENGINE

JX

DIAGNOSIS AND TESTING (Continued)