Dodge Journey: Engine diagnosis

ENGINE DIAGNOSIS - INTRODUCTION

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).

See ENGINE DIAGNOSIS - PERFORMANCE and ENGINE DIAGNOSIS - MECHANICAL for possible causes and corrections of malfunctions.

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that cannot be isolated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the following:

  • Cylinder Compression Pressure Test
  • Cylinder Combustion Pressure Leakage Test.
  • Cylinder Head Gasket Failure Diagnosis.
  • Intake Manifold Leakage Diagnosis.
  • Lash Adjuster (Tappet) Noise Diagnosis.
  • Engine Oil Leak Inspection.

ENGINE DIAGNOSIS - PERFORMANCE

CONDITION

 POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery.

2. Corroded or loose battery connections.

3. Faulty starter.

4. Faulty coil(s) or control unit.

5. Incorrect spark plug gap

6. Contamination in fuel system.

7. Faulty fuel pump.

8. Incorrect engine timing.

 1. Test battery. Charge or replace as necessary.

2. Clean and tighten battery connections. Apply a coat of light mineral grease to terminals.

3. Test starting system.

4. Test and replace as needed.

5. Check and adjust gap as needed.

6. Clean system and replace fuel filter.

7. Test fuel pump and replace as needed.

8. Check for a skipped timing chain.
ENGINE STALLS OR IDLES ROUGH 1. Idle speed too low.

2. Incorrect fuel mixture.

3. Intake manifold leakage.

4. Faulty coil(s).

 1. Test minimum air flow.

2. (Refer to Appropriate Diagnostic Information)

3. Inspect intake manifold gasket, manifold, and vacuum hoses.

4. Test and replace as necessary.
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped plugs.

2. Contamination in fuel system.

3. Faulty fuel pump.

4. Incorrect valve timing.

5. Leaking cylinder head gasket.

6. Low compression.

7. Burned, warped, or pitted valves.

8. Plugged or restricted exhaust system.

9. Faulty coil(s).

 1. Set gap as needed or replace plug(s).

2. Clean system and replace fuel filter.

3. Test and replace as necessary.

4. Correct valve timing as needed.

5. Replace cylinder head gasket.

6. Test compression of each cylinder.

7. Replace valves.

8. Check exhaust system restriction. Replace parts, as necessary.

9. Test and replace as necessary.
ENGINE MISSES ON ACCELERATION 1. Dirty or incorrectly gapped spark plugs.

2. Contamination in Fuel System.

3. Burned, warped, or pitted valves.

4. Faulty coil(s).

 1. Set gap as needed or replace plug(s).

2. Clean fuel system and replace fuel filter.

3. Replace valves.

4. Test and replace as necessary.
ENGINE MISSES AT HIGH SPEED 1. Dirty or incorrect spark plug gap.

2. Faulty coil(s).

3. Dirty fuel injector(s).

4. Contamination in fuel system.

 1. Set gap as needed or replace plug(s).

2. Test and replace as necessary.

3. Test and replace as necessary.

4. Clean system and replace fuel filter.

ENGINE DIAGNOSIS - MECHANICAL

CONDITION

 POSSIBLE CAUSES CORRECTION
VALVETRAIN NOISE 1. High or low oil level in crankcase.

2. Thin or diluted oil.

3. Thick oil

4. Low oil pressure.

5. Dirt in tappets/lash adjusters.

6. Worn rocker arms.

7. Worn tappets/lash adjusters.

8. Worn valve guides.

9. Excessive runout of valve seats on valve faces.

10. Missing adjuster pivot.

 1. Check and correct engine oil level.

2. Change oil to correct viscosity.

3. (a.) Change oil and filter.

(b.) Run engine to operating temperature.

(c.) Change oil and filter again.

4. Check and correct engine oil level.

5. Replace rocker arm/hydraulic lash adjuster assembly.

6. Inspect oil supply to rocker arms.

7. Install new rocker arm/hydraulic lash adjuster assembly.

8. Ream guides and install new valves with oversize stems.

9. Grind valve seats and valves.

10. Replace rocker arm/hydraulic lash adjuster assembly.
CONNECTING ROD NOISE 1. Insufficient oil supply.

2. Low oil pressure.

3. Thin or diluted oil.

4. Thick oil

(b.) Run engine to operating temperature.

(c.) Change oil and filter again.

5. Excessive bearing clearance.

6. Connecting rod journal out-of-round.

7. Misaligned connecting rods.

 1. Check engine oil level.

2. Check engine oil level. Inspect oil pump relief valve and spring.

3. Change oil to correct viscosity.

3. (a.) Change oil and filter.

5. Measure bearings for correct clearance. Repair as necessary.

6. Replace crankshaft or grind surface.

7. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply.

2. Low oil pressure.

3. Thin or diluted oil.

4. Thick oil

(b.) Run engine to operating temperature.

(c.) Change oil and filter again.

4. Excessive bearing clearance.

5. Excessive end play.

6. Crankshaft journal out-of-round or worn.

7. Loose flywheel or torque converter.

 1. Check engine oil level.

2. Check engine oil level. Inspect oil pump relief valve and spring.

3. Change oil to correct viscosity.

3. (a.) Change oil and filter.

4. Measure bearings for correct clearance. Repair as necessary.

5. Check thrust bearing for wear on flanges.

6. Replace crankshaft or grind journals.

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. Oil pump relief valve stuck.

8. Oil pump suction tube loose.

9. Oil pump cover warped or cracked.

10. Excessive bearing clearance.

 1. Check engine oil level.

2. Install new sending unit.

3. Check sending unit and main bearing oil clearance.

4. Install new oil filter.

5. Replace worn parts or pump.

6. Change oil to correct viscosity.

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

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

9. Install new oil pump.

10. Measure bearings for correct clearance.
OIL LEAKS 1. Misaligned or deteriorated gaskets.

2. Loose fastener, broken or porous metal part.

3. Misaligned or deteriorated cup or threaded plug.

 1. Replace gasket(s).

2. Tighten, repair or replace the part.

3. Replace as necessary.
OIL CONSUMPTION OR SPARK PLUGS FOULED 1. PCV system malfunction.

2. Worn, scuffed or broken rings.

3. Carbon in oil ring slots.

4. Rings fitted too tightly in grooves.

5. Worn valve guide(s).

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

 1. Check system and repair as necessary.

2. Hone cylinder bores. Install new rings.

3. Clean pistons and install new rings.

4. Remove rings and check grooves. If groove is not proper width, replace piston.

5. Replace cylinder head(s).

6. Replace seal(s).
    Cylinder compression pressure test
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