ASE A1 Engine Repair Practice Test

51. A wet compression test is being performed on a four cylinder engine. The number two cylinder's compression is below specifications and remains the same after injecting oil. This result indicates:

  • A. Worn piston rings.
  • B. A faulty valve.
  • C. A hole in the piston.
  • D. Excessive carbon buildup on the piston's dome.

51.

Answer A is wrong. If compression increases after injecting oil into the chamber, the piston rings are worn. This is because the oil fills the gap caused by the worn rings increasing the cylinder's compression.

Answer B is correct. If there is no change in compression after adding oil, the cylinder has a faulty head gasket or valve.

Answer C is wrong. Answer B is correct. There would be no compression is there were a hole in the piston.

Answer D is wrong. Answer B is correct.

52. A vehicle has blue colored exhaust. Technician A says this may be caused by weak piston rings. Technician B says this may be caused by a leaking fuel injector. Who is correct?

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

52.

Answer A is correct. Oil is burning in the combustion chamber causing blue colored exhaust.

Answer B is wrong. A leaking fuel injector results in black colored exhaust from the excess fuel burning in the combustion chamber.

Answer C is wrong. Technician A is correct.

Answer D is wrong. Technician A is correct.

53. Technician A says to remove the ridge on the engine block before removing the pistons. Technician B says a block's ridge will damage the new piston rings during installation. Who is correct?

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

53.

Answer A is wrong. Both technicians are correct.

Answer B is wrong. Both technicians are correct.

Answer C is correct. Remove the damaging ridge with a ridge reamer before removing pistons. This also prevents damage to the new piston rings when it comes time to reinstall the pistons.

Answer D is wrong. Both technicians are correct.

54. A vehicle briefly blows blue/gray smoke from the tailpipe when it's first started in the morning. The MOST likely cause of this condition is a:

  • A. Worn piston ring.
  • B. Lean fuel condition.
  • C. Leaking fuel injector.
  • D. Leaking valve seal.

54.

Answer A is wrong. Worn piston rings would result in blue/gray smoke at all times, not just in the mornings.

Answer B is wrong. Both a rich and a lean fuel condition will result in excessive HC's in the emissions.

Answer C is wrong. A rich fuel condition will result in black smoke emitting from the tailpipe.

Answer D is correct. A leaking valve seal will cause oil to leak into the cylinder's chamber over time, usually overnight.

55. Two technicians are discussing an engine with a collapsed radiator hose. Technician A says this is caused by a faulty radiator cap. Technician B says this is caused by insufficient coolant level. Who is correct?

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

55.

Answer A is correct. The vacuum valve in the radiator cap is sticking. A radiator cap acts as a two way valve that allows coolant to flow to and from the coolant reservoir.

Answer B is wrong. Insufficient coolant levels can result in engine overheating.

Answer C is wrong. Technician A is correct.

Answer D is wrong. Technician A is correct.