The internal combustion (I C) engines

are common in every vehicle. There are numerous

troubles associated with it. Many troubles

 Overcome many troubles by learning properly the

starting and operating the engine. It is

prescribed in the manufacturer catalog.

Experience is the best teacher to sense

the trouble. Take appropriate action to

tackle the trouble.

The procedures for trouble shooting of internal-combustion engines are somewhat similar for both diesel and gasoline engines. Do not overlook major differences. Overcome many problems by inspection. These may not require major repair or overhauling of the engine. Identify troubles from the engine erratic operation. Warning comes from the readings of the various instruments. Successful troubleshooter recognizes the trouble symptoms. He locates the trouble with ease.  Take the corrective action.  Various troubles are mechanical, electrical, chemical, noise and air pollution.   Common problems are

  1. Engine starting problems-Engine fails to start

  2. Bad Air fuel mixture- Engine do not start the fuel system

  3. Lack of compression- No ignition

  4. Combustion problems

  5. Rusting problems

  6. Belt problems

  7. Coolant problems

  8. Detonation

  9. Knocking problem

  10. Air Pollution problems

  11. Noise problems

  12. Stopping problems

  13. Battery problems

  14. Braking problem

  15. Clutch problem

  16. Accelerator problem

  17. Lubrication problem

  18. Air Filter problem

  19. Radiator problem

  20. Thermostat problem

  21. Alignment problem

  22. Balancing problem

  23. Governor Problem

  24. Fuel injection problem

  25. Visibility problem

  26. Emission problem

  27. Lower thermal efficiency

  28. Lower volumetric efficiency

  29. Leaking problem

  30. Sealing Problem

  31. Lighting problem

  32. Steering problem

  33. Gear box problem

  34.  Idling not smooth

  35. Engine pick up problem

  36.  Smoke problem

  37.  Overheating problem


    Scavenging consists of two steps *intake and exhaust).

      1. pushing out completely exhausted gases out of the cylinder

      2. Intake of fresh charge of air or air/fuel mixture for the next cycle


    Engine sucks a mixture of exhaust gases and fresh charge in incomplete scavenging. It is not complete fresh charge of clean air. This leads to incomplete combustion of fuel. There is loss of fuel and power. Scavenging is equally important for  diesel and petrol engines  with four and two strokes cycles. It is difficult to achieve in two-stroke engines. The overlap in their suction and exhaust strokes is small. Modify exhaust and inlet layout to achieve complete scavenging. Increase the velocity of fresh charge to push the exhaust gases out.


          1. Loop scavenging / Back flow scavenging

          2. Cross flow scavenging

          3. One directional / Uni flow scavenging

    Loop Scavenging / Back flow scavenging

    In this, the suction and discharge valves are on the same side of the engine cylinder. The fresh charge on entry into the engine cylinder forms a loop and pushes out the exhaust gases.

    Cross flow scavenging

    In cross flow, install suction and exhaust valves on opposite sides of the cylinder. Suction is in cylinder head and the exhaust valve in side wall. Intake is vertical and exhaust is horizontal. It is very common in four stroke engines.

    One directional or Uni-flow scavenging

    In this, inlet and exhaust valves are located on opposite sides of the cylinder. The inlet and exhaust gases move in the same upward direction and exhaust gases completely go out of the cylinder. Used in two stroke diesel engines.

    https://www.mesubjects.net/wp-admin/post.php?post=7680&action=edit         Testing Internal combustion engines

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