ASE A1 Engine Repair Practice Test

41. A broken timing belt on an interference engine can result in damage to:

  • A. The intake valves.
  • B. The exhaust valves.
  • C. The pistons.
  • D. All of the above.

41.

Answer A is wrong. Interference engines have a high-compression, small-displacement design.

Answer B is wrong. If the timing belt or chain breaks, the valves and the pistons collide, causing severe engine damage.

Answer C is wrong. The valves can strike the pistons when an interference engine is out of timing. Freewheeling non-interference engines have enough clearance between the valves and the dome of the pistons to prevent this catastrophic event.

Answer D is correct. A broken timing belt on an interference engine will cause the engine to spin out of time, causing the pistons to strike the open intake and exhaust valves.

42. A technician is checking for piston ring groove clearance. The proper technique includes:

  • A. The old ring and a feeler gauge.
  • B. The new ring and a feeler gauge.
  • C. Only a feeler gauge.
  • D. No feeler gauge is required.

42.

Answer A is wrong. Technician B is correct.

Answer B is correct. Clean the pistons in a cold tank and then clean the grooves with a ring groove cleaner before measuring.

Answer C is wrong. Technician B is correct.

Answer D is wrong. Technician B is correct.

43. A cylinder power balance test on an engine with sequential fuel injection indicates that the #5 cylinder is underperforming. Technician A says this could be the result of a clogged fuel injector. Technician B says this could be caused by leaking secondary insulation. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

43.

Answer A is wrong. Restricted fuel injectors and leaking secondary wires will reduce the cylinder's contribution.

Answer B is wrong. Both technicians are correct.

Answer C is correct. An underperforming cylinder could be caused by a mechanical malfunction like a faulty valve, electrical issues like the ignition, or a problem with fuel like a faulty fuel injector.

Answer D is wrong. Both technicians are correct.

44. A turbocharger wastegate is sticking. Technician A says a stuck open wastegate will result in an overboost condition. Technician B says a stuck closed wastegate will result in an underboost condition. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

44.

Answer A is wrong. A stuck open wastegate (P0299) results in poor performance and a lack of horsepower because the exhaust pressure bypasses the turbine wheel.

Answer B is wrong. A stuck closed wastegate produces overboost. Overboost results in detonation from the excessive cylinder pressure.

Answer C is wrong. Neither technician is correct.

Answer D is correct. Neither technician is correct.

45. An engine has excessive crankshaft endplay. Which of the following is MOST likely causing this condition?

  • A. Camshaft bearings
  • B. Thrust bearings
  • C. Crankshaft main bearings
  • D. Rod bearings

45.

Answer A is wrong. Thrust bearings locate and keep the crankshaft from moving forward and backward in the engine block.

Answer B is correct. The thickness of the thrust bearing indicates crankshaft endplay.

Answer C is wrong. Answer B is correct.

Answer D is wrong. Answer B is correct.